Wednesday, December 25, 2013

Got Rope?

I've had this 30-year old anchor rode hanging in a tree for 15 years, serving a second life as a Tarzan swing. I've got a Kevlar genoa sheet with a shattered core, no longer trust worthy for anything critical.

The rope ladder was a simple project. I've wanted something that was compact, couldn't harm gelcoat, and could be used climbing in or out of the tender. This took about 20 minutes and about 30 feet of line (2x the length + 3' for each rung). A fun night-before Christmas project, complete across my lap, with a glass of hot tea at my elbow, while watching The Polar Express with the family.

The door mat required 100 feet of 1/2 inch line and about 2 1/2 hours to complete. The knot in the middle is rather a lump underfoot, but it looks very traditional. The wrap and sewing took the real time. I soaked it with the borax/washing soda/baking soda anti-mildew blend when finished. My mom thought it a charming gift; since we had enjoyed it on the boat and in the backyard for many years in previous incarnations, it has history with her children and grandchildren.

And 2 lumps of old rope were thus consumed. Good.


Via Ferrata Tethers--Some Good Ideas, But Not for Sailing


Via ferrata trails, literally iron ways in Italian, are climbing trails equipped with rungs and safety wires that allow fit but unskilled personnel to move quickly and safely over difficult terrain. Though they date back into the 19th century, they are best know from their use during World War I, moving troops through the mountains.  Since then they have expanded to thousands of tourist routes in Europe and the United States. Since tether technology is the focus of this post, I'll leave history research to the reader; the internet is great for that.

The climber is protected falling all the way by a pair of tethers that follow a safety wire to the side of the rungs. Periodically, the wire is fixed to the face, and this is the challenge; these points are generally  10-20 feet apart, allowing for  serious falls before the tether takes, and requiring the tether to absorb a great amount of energy, more than a dynamic rope alone can handle. Dynamic ropes are rated for a fall factor of 1.8, whereas a via ferrata fall can be fall factor 5 or more.


The solution is a more extensive energy absorption system, including either friction through an aluminum plate or a tear-type energy absorber, like a Screamer.


Why wouldn't these make useful sailing tethers?
  • The allowable impact force is much greater, since the load is taken on a seat harness rather than a chest harness; the human tail can take a lot more force than the ribs. Sailors need a softer catch.
  • The falls are really much greater. A sailor will never see an impact beyond fall factor 1; the ISO drop testing required by the ISAF rules is based on a FF1 with a 100Kg mass.
  • The end clips on via ferrata tethers are applicable and gaining popularity. The West Marine tethers are now Kong Tango via ferrata biners (pictured on tethers to right), and I like them very much. Fast on and off, one-handed even when cold and wet, locking, light, and fit over most handrails too. Because they are aluminum, they do require periodic lube and rinse. Mine have held up very well, like new after 2 seasons.
  • Harness attachment. Sailors like a quick release on the tether, something that can be removed under load. Climbers opt for a locking biner, since no possibility of accidental release is acceptable. Most often the tether is cow-hitched to the harness.
  • Length. Sailors like dual lengths (2-3 feet and 4-8 feet) while climbers are restricted to 2 matching arm's length tethers; they never want the clip to move out of reach (if it snags below you this is a real drag).
Certainly there are some ideas here, some worth adapting, but the application is different.

-------

Note on recalls. Because of the extreme nature of the falls and untrained nature of many users, there is some history of failures, most often fatal. In general, the causes have been:
  • Fall too great. Anything of 10 feet is trouble and over 15 feet is beyond the equipment rating. The via  ferrata trails generally recognize this, placing tie points ever 10-15 feet, but risk is often part of  climbing; if it looks too scary, go down.
  • Worn friction rope. Some designs rely on a rope slipping through a plate with many holes. If the rope wears through use--tour groups use them daily--the rope slides more easily and insufficient energy is absorbed. This type has gone out of production because they are too difficult to inspect.
  • Poor or worn stitching, or any other construction fault, though this type of failure can result from too long a fall.
ALL via ferrata falls are bad, far more dangerous than falls on a climbing rope. They feel safer but are not. The impact forces are high and there is much to hit on the way down.

Monday, December 23, 2013

Fids

When we need something, we run to the corner store store, or worse, the mall. When we some thing for the boat, we run to the chandlery, West Marine most probably. What we need is on the shelf. Seldom do we give a thought to making simple tools, though isn't that capability what made us human? Back in the day, for a workman to make his own personal tools was central to the craft. What sailmaker bought his fids from a store? Seam rubbers and wooden fids were crafted as needed, to the individual taste and hand of the worker. Some made fids with a handle or a turk's head worked in a turned grove; this probably worked best for large course hemp lines, but on a small boat with synthetic line, needs have changed. Even my wooden fids are smooth, so that they can pass through one line, towing another. The point is they were made by me to work best for me.

My finishing bench is of my own creation, fits nicely next to my favorite chair, always holding what I need near at hand (I have another sewing kit on the boat). It is a bit smaller than old-time benches, better suiting the size of my projects.

My wooden fids were turned from scrap hardwood dowel in a drill press (I have a lathe, but the drill press is handier for this) and have been worn smooth. There is a hole in the butt to accept a towed line, when that is required.They took perhaps 15 minutes to make, and I enjoyed the process.

My hollow fids are discarded knitting needles. Ask your wife or daughter--I'm they have a few mismatched needles about--or go to a thrift store. Cut to length, smooth the outside edge with a file or sandpaper, and clean the inside edge with a hand held drill bit. I seriously doubt the commercial hollow fids were purpose built, as the volumes are far too low--they are re-puposed knitting needle blanks, I'm sure of it.

Wednesday, December 18, 2013

Tangier Island Seeking More Cats--Who Would have Thought



When we first visited Tangier, we were greeted at the Park's Marina by about 50 cats, all fed by the owner. At some point, someone had a problem with this state of affairs, and the town’s leaders brought in a SWAT team of veterinarians to spay and neuter their increasingly out-of-control cat militia. Unfortunately, they hadn't done all of the math.

RiverottersMDNR
Now the otters have the upper hand, stealing soft crabs so conveniently placed in shedding tanks, available nightly under convinient work lighting.

Some of the waterman have gone back to keeping cats on their shedding platforms. Though a cat is no match for an otter, a group of cats is sufficient deterrent.

I suspect we'll see more cats during our next visit.

Read the full text here.

 

Sunday, December 15, 2013

Heater Efficiency

Marine space heaters are not typically rated for efficiency by any approved method, and Internet folks are forever commenting on what is efficient or not efficient, without any engineering basis or understanding of the math. But it isn't complicated and engineers have long known you can calculate everything you know from the stack conditions. After all, what goes up the stack didn't go into the room.

I described my heater installation and early experiences, but I only estimated the efficiency without rigorous measurement. Time to fix that.

Stack Temperature. Obviously, cooler is better. Since the stack temperature on my Dickson P9000 is 185F on a cold day (40F), that gives me a starting point efficiency of 88.5%. However, since the Dickson unit preheats the combustion air with flue gas, this gives a 4% increase to 92.5%. So little, you say? In effect, I'm simply moving the exhaust temperature 200F. It is worth doing simply to keep the hull fitting cooler and to reduce burn potential on-deck. More importantly, while dropping the temperature of the exhaust 200F is not a big deal in terms of efficiency, it means the P9000 exhaust can't damage a nylon rope. That is a big deal.


Excess Oxygen. However, the easiest way to get a cool stack is plenty of excess oxygen. A few percent is desirable, but the rest is energy wasted heating air. I get a reading of 5% on the Dickson heater, and that costs me 2% on heater efficiency; down to 90.5%.


Ambient Temperature. It is also necessary to do a correction for ambient temperature, compared to the base temperature used int he first graph (70F). Colder inlet give the impression of higher efficiency. By observing performance at 40F vs. 70F I gave myself some false credit. Subtract 1%. Down to 89.5%.


Overall Efficiency. Just start at the top and add them up. 88.5% + 4%(preheat) - 2% (excess O2) - 1% (testing temp correction) = 89.5% thermal efficiency.

AFUE (Annual Fuel Utilization Efficiency) Rating. This rating, found on every home furnace, is a bit different, as it includes losses up the stack when the unit is not firing; for example, fire places can be great heat wasters since warm air goes up the stack even when not in use. However, all of this is irrelevant to a simple marine heater such as the Dickon P9000 (it runs steadily without cycling--it can be turned down), I have not considered it. However, for the purposes of comparison, the AFUE is generally about 15% lower than the thermal efficiency. However, since the Dickson is sealed (all combustion air comes from outside) only a minimal 5% penalty is applied. Electric heat is assigned no penalty, so I am being conservative. 84.5% estimated AFUE.

Bottom Line. So how does this "stack-up?"  This little marine furnace rates as mid-efficiency. Not too bad for something the size of a toaster and much better than more primitive predecessors.


Saturday, November 23, 2013

Singlehanded Kayak Loading--Onto the Car with a Bad Back...

... or if you short, or even exhausted after miles of paddling.

This is so obvious it should be in the owners manual. They should use it as a sales pitch. But it didn't occur to me until after returning from a trip with our stuff piled in the driveway, that most kayak wheels look kind of like a bike rack with wheels instead of arms. They have the same padding and the same angle, and at least one strap for securing wheels to the boat.



  1. Secure the existing strap to the roof rack with the padded arms straddling the break in the roof line.
  2. Secure a second line to the bottom of the hatch to hold it down. I had to add this one, a few minutes work.
  3. Roll it up and then flip it over to better secure.



Yes, this can be done simply with a blanket or large towel, but by the time you secure the towel that takes time. Fail to secure the towel and you'll lose paint for certain. The heavier the boat and the higher the roof, the better the wheels work.

 While I don't have any trouble simply lifting kayaks onto my Forrester (pictured), the wheels are a BIG help when loading onto a high SUV or van, which is nearly impossible for a 5'8" guy; I simply run out of height by the time I reach over the rack.

Saturday, November 16, 2013

Marking Furler Line

I had always marked one spot on the furler line; the 100% setting, which I used when reefed. However, adding the inside genoa track prompted me to refine the system.

  • Wide band: 110%, just short of touching the shrouds and spreaders. While it is possible to run a full genoa between the shroud and the spreaders, it risks sail damage and is more trouble than it is worth.
  • Medium band: 90% Just short of lapping. A nice setting if single or double reefed, going to weather.
  • Narrow band: 70%. Small, only 25 % of full area. Good for double reefed and blowing like stink.
To insure the whippings are tight and can pass the jammer smoothly, they should be smaller than the line. This is easily accomplish by holding the line stretched between 2 winches while whipping.

 
Yes, you can always adjust as you go, but rolling sail in a breeze isn't good for you or the sail. Advancing the furler line to the correct setting before unfurling is MUCH easier.

Fog


Sunday, November 10, 2013

Amsteel... or Not?

Some folks are so stuck on Amsteel that they probably use it for shoe laces (I've seen soft shackle key rings). Others treated as some new fangled nuisance, like polyester sail cloth, that will soon go away. I've been using soft shackles on my genoa sheets for a little while now and I like them. Are there other applications I should consider?

In use

Genoa Sheet attachments. Why? I recently add an inner track which requires changing sheets occasionally (there are 2 sets now). I didn't trust snap shackles on a flogging sail, couldn't justify the expense of  J-locks, didn't fancy getting whacked on the head or having the mast pummeled. I could have used stropes tied from polyester line (I did use these for a time), but the strength is close and there is a slightly greater chance of opening (they never did). The hollow braid and slipperiness of Amsteel permits some unique splicing options.

Genoa sheets. I recently installed some line that was donated to me (testing left overs). Turns out it was 1/2-inch Warpspeed (21,000 pounds BS, $5.67/foot). Stiff as hell but good in this application, should last a very long time. Nice hard on the wind, where stretch means the sail gets full when a gust hits, which is when you want it flat. But I would not have spent $300 for it! I didn't realize it wasn't Staset until I saw how it handled and looked more closely at the core.

When something wears out

Lifelines. Certainly, in a few more years. I will go 1/4-inch with 9/16-inch webbing on the wear spots, which even with UV should be good for 10 years. Easy to do, nice hand, and light.

Jib halyard. My jib halyard has one tight spot where it passes through the masthead. I think the smaller size will resolve the pinch. I will have to splice to something larger for the jammer.

Spin head attachment. If it breaks. Not likely. Or if I need it elsewhere (more likely).

Spin tack. The metal shackle snags and scrapes on the forward lifeline. This will be converted to a soft shackle soon, certainly before the lifelines are changed.

Bridle to chain. If I lose the Mantus hook I'm testing, Amsteel as either a loop or a soft shackle will be next. Easier than the plate I was using. Honestly, for me a sling and carabiner work very well.

Main Halyard. Lower stretch would be nice, but that will be some years.

Topping lift. Light, don't often adjust.

Bad applications (to me)

Spin sheet attachments. Snap shackles are faster.

Main halyard. I prefer a knot. Easy to trim a few feet every few years, to move wear spots.

Jib halyard. Only pin shackles fit furler.

General block attachment. I would be open to this, but in any cases there are sharp edges. Pin shackles generally last forever.

Lashings. Generally nylon or polyester are strong enough when passed many times. Amsteel knots poorly, giving no increase in security over a good lashing.

Main sheet. I want some stretch during jibes; a high mod line increases the stress on the traveler bearings. I wish my traveler was not Spectra and I will change it if I find something cheap.

Jib sheets. Good application, but not cost effective for this boat. I have polyester for my reaching sheets, which is fine, and Warpspeed for the windward sheets which is perfect for that.

Spin sheets. Again, I like some give.

Tying things on deck. Poor knotting, simply don't need the strength.

Anchor bridle. You need the stretch of nylon with chain. But if you are using all-nylon rode, Dyneema may be just the thing to limit yawing; I've tested it, it works.

Jacklines. It depends. On smaller boats the stretch of polyester reduces forces. On larger boats, Dyneema is perfect.

-----------

And so it seems to be limited in application. Neat stuff, though.




Wednesday, November 6, 2013

Sucking Bottom

I never thought of my PDQ as a freighter, but they have a few things in common. I keep expecting--hoping--her to behave like a beach cat, but she's not.

Something we all keep any eye on, at least occationally, is maximum speed under power. It 's an indicator of whether the engine is tuned well and the bottom is clean. If she reaches top speed, we know those things are fine.

Yesterday as I was motoring back in I pushed the throttle wide open and she went... 6.5 knots. I've been seeing 7.4-7.5 knots since I extended the transoms, so something had to be amiss. I looked over the stern at the transoms; they were 6 inches under water unde conditions that should have them just above! Am I taking on water?

And then it occurred to me that I was sprinting across 4.5 feet of water and the hull was feeling the bottom, both in terms of excessive stern wave and reduced pressure under the deepest part of the hull. In fact, I was much closer to the bottom than my nominal 3.5 feet of draft would suggest. I suppose I might have touched, though I didn't feel it. Perhaps sprinting across shallows is not so smart.



As soon as I moved into the channel--8 feet--the speed jumped to 7.5 knots and the transoms came up. I think that's fooled me a few times over the years, wondering what I'm dragging.

------------


Pilots bring freighters into port often reduce speed in shallow areas to avoid what is called squat. It is more than simple caution and is calculated before entry.

Sunday, November 3, 2013

The Poisoned Pen

In every town there is one critic that with a reputation for ruthlessness, possessed of an acid pen that can find nothing good in the world of the arts. New careers are gleefully smashed and that critic feels a quickening each time some new talent cries out.

My first career was in small business, and though I have worked for giants, I've had a few toy ventures on the side. We all want some success that is "us." I have a sensitivity for small businesses, and most marine products vendors and manufacturers are, in the scheme of things, tiny.

A few days ago I submitted an article to my editor; the closing sentence of the e-mail stated that "so-and-so is not going to be happy with me." I had bashed his product a bit. I didn't say it was bad. I explained that my test was in fact, a bit severe... but that other products had passed. I explained the product did no harm. But in spite of the fact that this man and his customers believe the sun rises and sets on his product, I could find nothing significant to recommend it. So I didn't. And my editor told me not to worry about it.

We have five choises when grading a product, and a product can be more than one of these.
  • Best Choice
  • Best Budget Buy, reserved for products that are cheap and work.
  • No comment given
  • Not Recommended, reserved for products with significant flaws
Awarding Best Choice and Best Buy is always pleasant, particularly when a product surprises you with great value. I can think of some fuel additives, vent filters, holding tank treatments, sanitation hoses--the list is long--where awarding top rating was a pleasure. They were impressive product, doing more than I expected. There are always some products in the middle of the pack that are still a good value that just don't merit a recommendation. Sometimes I feel bad about that. I hope they take it as a suggestion that they look more closely at their competition and improve. We all need to strive.

But I never enjoy awarding Not Recommended, not even when the product has manifest flaws. Did I miss some virtue? Why would anyone bother to bring something useless to market? Unfortunately chandlery's shelves are filled with products that simply don't work. Cleaners that don't or that are over priced for what they do. Fuel additives that make corrosion worse. Mildew treatments that don't work as well as common chemistry. Things that are cheaply made, not worth carrying home. I wish that the West Marines and Defenders of the world would help by kicking some of the junk to the curb, but they sell whatever people will buy, though they must know that some of the fender-holders and clothes pins and fuel additives are complete rubbish. When I give a Not Recommended rating, I really mean it.

I hate that in addition to boosting up the innovators, I must shine a bright light on non-performers that so often tell a convincing story. Some take their lumps with quiet dignity. Some have told me that their products "can't be tested in the laboratory" or even simply that it "can't be tested." But they have testimonials a plenty, they say. Never mind other passed the tests. Often the biggest names cry the loudest assuming we are a group of non-technical tinkerers, surprised when we can back-up our findings with a better understanding of the engineering and chemistry behind their product than they have; a bunch of babies, they should test their stuff better and not rely on a big name. And of course, some of the big names are good.

And even when I make recommendations that I am completely sure of, there can be distortions. 
  • A "great review by so-and-so," proclaims the add. Only I didn't review that product.
  • A "rave review," only that review was for a different product, not everything they make.
 Sometimes I'm told the writing is dry, lacking enough opinion and personal judgment. Can you not understand why? Science needs to be dry, even when it cries out for opinion and theorizing.

So I moderate my poisoned pen, while I still call em' as I see em'.

_________


I really wish I could have given concrete examples. But not in this context.

Not every product that claims a "great review by so-and-so" is telling the truth; sometimes that review was for only one product they make, while the others are useless.

Thursday, October 24, 2013

PDQ 32/34 tacks through less than 90 degrees--Or Sheeting Angles Part II

Rev. 11-16-2013

Ever since I stretch the hulls from 32' to 34' I guess I've been on a performance quest. I'm not a racer but I do like sailing efficiently and I like doing it by proper tuning, not hurling money at the problem. No Kevlar sails, tapered sheets or high-tech halyards.

In Sheeting Angles and Keels I proposed that by moving the genoa track inboard to a better sheeting angle I could get the boat to tack through about 92 degrees over ground vs 120-128 degrees with outboard leads   and see a 21% improvement in VMG. Great expectations. And that is exactly how it turned out.

Tacks through 85-90 degrees full-and-by.
VMG up 20-25%



Yup, I gave up a little boat speed, but now she points the right way and is much easier to steer to windward, not so twitchy on the edge of shaking sails and irons. With the inside lead position there is a MUCH wider bucket of acceptable VMG, from 45AW to 55AW; even 60AW is a little faster with the new lead position, since it is full sail instead of near luffing. I'm sure there are many times when higher pointing will mean fewer or no tacks, and that increases the gain further. It is helpful that the PDQ 32 actually has slightly greater draft and keel area to sail ratio than the PDQ 36. It is also similar to the sheeting on the Stiletto27 and 30, also beach cat rigged boats. Anyway, it works and this should have been the factory layout with a few tweaks. Much faster and better balanced than the self tacking jib.


Note that the outside sheet is still attached but slack; I will be putting a soft shackle on this to make it removable. I like the low-profile Garhauer snatch blocks; a great value and a lot of strength in a small package. I switched to low lead cars later; snatch blocks are too high and cause winch overrides.

A bunch of notes for those who might want to try this. First, the basics:

Do other things to make the boat fast. Anything that makes the boat move better will reduce leeway by increasing flow over the foils. 
  • Clean bottom
  • Watch the weight
  • Watch the windage
 Outhaul. Many cruisers set-and -forget, but this is wrong. A full main gives more power reaching, but a flat lower main is mandatory for pointing high. With a full lower main...
  • The jib will back wind the main and the slot is closed.
  • The mainsail leach will hook to windward (slow) when the boom is properly located near amidships (the traveler will be about 6-12" above the center line when beating, depending on the wind).
The outhaul is typically adjusted with the winch on the mast. If you have a main with an attached main (factory) you REALLY have to crank up the tension to get it flat; you're stretching cloth. With a loose foot it is easier, but the result is the same. IF you are going to set-and-forget, leave it flat. With the reefing points, make certain the foot is pulled flat with each reef; there is no good reason for a full reefed sail; you are trying to de-power and reduce drag. There is a too-small cleat on the boom for the outhaul and it is tricky (lead the line under the cleat) to cleat the line without loosing tension; I may add a jammer to the boom; I'll see how the new sail fits in a month.

Lead location. The fore-aft location is critical. There must be some provision for twist; the upper genoa leach must be able to open. If the existing location is proper, the new location will be a few inches aft. I used a 2-foot track, but in retrospect I should have used a longer track in case I get a new genoa with a different geometry. Monohulls will often use an extreme forward position reaching to limit twist when the sheet is eased, but this is seldom done on multihulls; if you take the trouble to adjust for reaching on a multihull you use your beam and move the sheeting point forward AND to the rail, nearer the midships cleat for the PDQ 32. Monohulls don't have the beam to do this, unless they use a wisker pole, which will probably drag in the water and break if reaching in  breeze.

Sheeting. There are several option with an inside tack and I have played with them all. The best choice depends on what sort of sailing you are doing.
  • Use a 15-foot utility line as the inside sheet. Grind the sheet in with the outer sheet, hook on the utility line, release the outside sheet and grind the inside sheet. In fact, the 15-foot line can be left attached and allowed to flop through the tack; it's too small to matter. This is what you see in the picture above.
  • Use a spinnaker sheet. Again, it is used as a utility sheet, released for tacking. Or the outside sheet can be removed and the spinnakar sheet becomes the working sheet and tacking becomes normal. I'm going to try this, attaching the outside sheets with Amsteel soft shackles. One down side is the sheets are one size too small for this duty and there is one more turning block.
  • Dedicated inside sheet. At first I thought that would be too much mess, but today I tried a removable inside sheet (attached with strope) that was rigged continuous, like a beach cat; this shortens the line and makes for quicker tacking. Definitely a good plan for a boat that does not have a spinnaker; there is no need to install the outside track, particularly if a 120% genoa is selected.
  • Note that on starboard tack the mainsheet must be on the forward winch and that grinding is hindered; you cannot turn the handle more than 120 degrees. However, if the main is already mostly in, a rocking motion works fine for trimming. If your genoa sheets more forward the track will be further forward and the problem goes away. 
Update: I've gone to using a complete separate set of sheets, detaching the set I'm not using. This is much handier when beating to windward, which is practical with the new found pointing ability. I have also chosen to rig them as continuous, as seen on beach cats. This combination seems practical for single handing in breezy fall conditions, though it does seem to leave more rope in the cockpit. While there is more of it, however, it is easier to manage since it doesn't tangle (no ends to make knots) and can be reached from one spot for either coiling or tacking.


Furling. While it is possible to sheet a 150% genoa inside the shrouds, it is really simpler with a 120% genoa (one that ends at the shrouds). Sheets hang-up less too. Alternatively, you can do as I did during this test and furl the 150% genoa slightly. To save trial and error, it is a handy practice to mark the furling line with a thread whipping at 40%, 80%, and 120% (different colors or different number of stripes).

Tighter sheeting angles. The sheeting angle is now ~ 16 degrees vs. the 10-12 degrees found on some monohulls. While tighter angle swill work on a boat wit low windage and a deep keel, that would be a mistake on a cat with high windage, shallow keels, and better footing speed potential. Even my Stiletto with a deep board would often go up wind better (rough conditions) when I hauled the lead out to about 16 degrees. The inside positions were only for smooth water.

This has been greatest performance enhancement for the dollar I have found for the PDQ. If you have a genoa, this is a no-brainer. With Gauhauer parts it was ~ $280.

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(although this is not the gear I used, it is what I should have used and what I ended up with.)
  • Garhauer 1 1/4-inch track, 2 feet long.
  • Garhauer low lead block LLC-2. (I started with Garhauer 30 SN snatch blocks on cars and got horrendous over rides.)
  • Backing plate (under the ceiling; I threaded 1" x 1/4" aluminum strip I had, but other things will work.)
This is a Garhauer LLC-3 on 1 1/4" track, but the LLC-2 would be better.

And don't forget to drill/remove core/epoxy/re-drill/butyl the track mounting holes.

----------

I need to build a new speed polar. I'm working on it.

Friday, October 11, 2013

Oh Dear...

In order to listen to a movie without inverter hum (I've got Bose speakers but my inverter puts out square wave power) I decided to plug in. I spent the night on the boat in order to be closer to Annapolis for the morning boat show.

But all the GFIs were tripped.


Let's see...
  1. Only 4 non-water proof plugs, in addition to the 2 plugs on the box.
  2. One unrestrained hot plug that can be kicked into the water.
  3. One plug that had enough tension to pull the box off the piling (fender was rigged against it).

After unplugging the GFI-trip offender I left a note gently explaining why this is collection of cords is dangerous and non-functional. The boat has not left the dock since the new owner bought her, and I doubt if it ever will. I've not heard the engine run. He did ask me if the problem with the tap water could be that the tank was empty....

Ordinarily I rely on solar and and inverter and only plug in for a few hours when I am present. I am quite glad of that.

---------

When I came back 10 days later...
  •  The note was still in place, unread.
  • A cord had been added, reaching to the next outlet over (2 slips, not in use).
  • The outlet was still tripped. I'm guessing it was either still wet and couldn't be reset (probably not) or didn't know how to reset it (probable). Since there was nothing plugged in, it should not have tripped even if raining. 
  • The outlet worked fine, after I reset it.
It had not rained since. Perhaps that outlet is less sensitive. Perhaps it will trip next rain.

Wednesday, October 2, 2013

Searching Forums and Blogs

Perhaps everyone but me knew this trick already, but here goes....

Often forums, blogs, state government sites and even many commercial sites have lame search engines. Blogger's search engine is pretty good, but even a plural (boat vs. boats) will throw it off the sent. Today I learned a very simple solution. For example, to find posts on genoa sheeting angles on Multihulls4us...

site:www.multihulls4us.com genoa sheeting angle

or 

site:sail-delmarva.blogspot.com genoa sheeting angle

... will take you right there with much greater accuracy and fewer false leads than the search engine on the site or Google without the site: command.

Tuesday, October 1, 2013

Saturday, September 21, 2013

To Cover or Not to Cover?

Cover, obviously....

This boat is a poster child, the upper portion of the enclosure covered for a time, then niether part covered. The lower portion has become barely translucent:


Often the bird dropping are an even larger problem; the vinyl must be cleaned every trip and residue that sits for more than a few days etches a permanent mark.

The covers on the fixed windows (polycarbonate) have cause no additional scratching, have slowed UV damage, cool the cabin, reduce window cleaning, and reduced scratching. Simple enough.

But what to cover the soft windows with? Concerns abound that without some padding or lining the canvas will eat the vinyl whole, perhaps worse than UV sun exposure. Others use plain Sunbrella with success. I've taken a hand full of Sunbrella, rubbed it on Strataglass and seen no damage.

On the right is a weather beaten 16-year old cover, the edging eaten
right off by the sun. Under it is pristine 16-year old Strataglass. The rest of the dodger has been replaced twice and is not as good.Could the skylight have been better protected? No, I don't think so.

On the front windows I have a non-contact cover. It was simpler to build and seemed like a better idea... though I don't know that it was. The front and side windows are already far worse, the result of scratching from rolling and kayaks sliding by.


Would a lined Sunbrella cover be better, as many have suggested, or would it only hold more grit and be more prone to scratching? Would it be like cleaning the glass with a grit-encrusted rag? Always puzzlement. I pretty sure plain Sunbrella is the answer.


Or not to cover....
In very windy anchorages I've been told that covers can flap and scratch the vinyl. No question, if you take Sunbrella and rub it against vinyl, at acts like a fine rubbing compound. Clean cotton, by the way, will not do that and so it can be used for cleaning and polishing, but as a cover it wouldn't last and certainly wouldn't stay clean.

-------

No universal answer, it seems.





Sunday, September 15, 2013

Sheeting Angle and Keels


rev. 9-18-2013

Cruising cats are not generally weatherly, and the PDQ 32 is no exception. But encouraged by the fact that some fine tuning (transom extensions clean bottom and a weight loss program) has made the speed polars quite attainable, I'm encouraged to move on.

The transoms helped. Less drag equates to higher speeds and higher speed, even a little, means higher lift on the foils. This is critical with low aspect keels, something I learned well in my years of sailing no-keel beach cats; they only point if you keep them moving.

New sails. My genoa sets perfectly (other than the sheeting angle, which we will get to). My main on the other hand, is a bag. But I still want to get a few years more and I'm patient. Jessica's just starting school and I still feel guilty about spending. It will pass. No question, a flatter and faster main will aid pointing, though I wouldn't expect any change off the wind, hence the low priority.

Sheeting angle. A few quick calculation show I use a self-tacker angle of 12 degrees but a genoa angle of 24 degrees. For comparison:
  • Very weatherly keel boats: 7-9 degrees.
  • Cruising monohulls: 9-12 degrees.
  • Dingies: 9-12 degrees.
  • Stiletto 27: 9 degrees.
  • Prindle 18: 12 degrees
While the PDQ doesn't have the best foils,clearly we can do better than 24, which is a reacher angle. But with beach cat rigging (3 shrouds, no back stay), I can't sheet tighter than the shroud.

I will probably add a short run of 1 1/4-inch track between the winches and just outboard (about 2 feet behind where the green tape is, the result of more test sailing) (both winches are the same size). Figuring the space will be tight and the lead may interfere with grinding if not tweaked just so. Most probably I will use the spinnaker sheet as the alternate jib sheet, which will require using a snatch block; I found a compact one from Garhauer that I like. I've got to be certain nothing interferes with normal genoa and spinnaker operation. I suspect a mock-up will be required, to get it right the first time. And more testing.

The track will be out of foot traffic and no new lines are needed. Unless the spinnaker is used, everything can be left in place. If the spinnaker is used, the line transfer should take only a minute, making use of a snatch block on the inner track.

I intend to replace the fixed aft block with another slider, so that both can be adjusted. The cross haul line in the photo is only to hold the snatch block in place during the photo and is not a part of the proposed system.


A side view shows that to get the same lead angle on the higher deck I can be somewhat forward, though any time you move inboard you move aft. The tighter the jib, the greater the risk of hooking the leach into the main up high.



If we were to bring the sheet inside the shrouds, I can go as close as 17 degrees before the cabin top gets in the way. Although 7 degrees sounds minor to the non-sailor, it equates to about 20 degrees of potential pointing, which is huge. We have tested this by barber hauling to an opposing winch (awkward--the line splits the cockpit) (would need to be reset on each tack) and after leeway found about 8-10 degrees course-over-ground improvement, and about an 30% improvement in VMG (velocity made good to windward), which is huge. Additionally is the promise of fewer tacks, which add to that improvement. Yup, gotta do it. We will need to add a short track just between and outboard of the winches with very low profile blocks (to get a good winch lead).

While we certainly must consider rough conditions (the below is based upon semi-protected water observations), the calculations below show the potential benefit of inboard leads. Also interesting is the relatively small change in VMG over a range of angles, thought that simplistic analysis ignores the reduction in the number of tacks required.
 



Keels. Of course, this will be further helped if the keels were optimized. PDQ designed the keels for balance on land, not in the water; nice when dried out, but way too far forward under sail. She loves to weather vane into irons when you're not looking. More area aft might help.

This is a more radical way to add area; a center board that would drop down when needed for leeway and balance. Certainly there is room in the under bunk storage, but I think the added wieght might cost more than the leeway, to say nothing of the complications in construction, operation, and mainatance. This has been done on both cats and monohulls.


PDQ keels are also not very efficient, being low aspect. Several sources suggest that about 5% of the sail area is good for this type and this sort of boat. With about 620 ft^2 of up wind sail area, that would suggest 31 ft^2 or 15.5 ft^2 on each side. Since the existing keels are more like 12.3 ft^2, we are seriously lacking in area. With the factory self-tacking jib, the up wind area is only about 506 ft^2 and the factory keels make perfect sense (12.6 ft^2 suggested). On flat water with a wide lead angle it also works with the large genoa, but when it gets rough, not so much. If I tighten the lead angle to 14 degrees, even more trouble.

The existing keels have a very blunt trailing edge, perhaps 5/8-inch wide. What if we extended this out to a fine edge? that would add about 1 ft^2 per side. What if we add a low angled fence keel for a short distance behind the keel, perhaps 30 inches long? Another 1.8 ft^2; not efficient because low aspect, but thin and very low drag. Both would be simple to do while out for painting and cost very little. No additional draft and nothing to snag on the bottom. I have a chain rode, so keel wraps are a non-issue. This would get the area back into the design pocket.

Note: I did fair the keel, 10/2015. Yup, really helped with balance and VMG. See Good Old Boat Magazine, 2016, for the story.

----

The plan? I think the inside genoa leads may appear within a few months--a little more testing and figuring. The new main and keel mods will wait for the next haul-out; I think they will make a fun 1-2 punch. While she will never be a reaching machine like my old Stiletto, I think she will be getting up and down the Bay a good bit quicker than stock, and smoother too; a very fast cruiser for her size. I'll have to calculate new speed polars!

Speed isn't everything. Efficiency means I can also reef earlier without loss, and that makes for easier, safer sailing. 

Friday, September 13, 2013

Reeving

You'd think reeving a block would be second nature to an old sailor, but I'm always forgetting how to reeve a 6-part tackle at 90 degrees. Weave the rope in any other order and you're just throwing money away.



Look Mom... nothing touches!


The problem is friction. For the same reason that you can hold a 2,000-pound load on a winch with 2 fingers by virtue of 3 wraps, a tackle where the line going up rubs against the line going down  will waste energy from the start and virtually lock-up when it gets within 6 block diameters of finished.



I keep this cheat sheet handy for when the davit tackle gets tangled; typically a well meaning guest detaches it and drops it to one side, unknowingly passing the block through the tackle. Oops.

4:1 blocks have a trick too:

Wednesday, September 11, 2013

You would think after 30 years of messing about in boats I would know what basic terms mean. But it seems they mean different things to different folks.






I always assumed "wind" meant the actual wind. The true wind. The first texts I read on catamaran sailing made it quite clear that is what the author believed. Something like this:

Pinching. Probably closer to the wind than Close hauled suggests.
Close hauled. As near the wind as good VMG indicates.
Full and by. Just eased a tick. Full sails. Often better VMG in steep chop or performance multihulls, but depends on the boat.
Close reach. Between close hauled and beam reach, about 67 degrees off the true wind. On fast boats this can be a lot like full-and-by, while slow boats have eased sheets.
Beam reach. True wind on the beam.
Broad reach. True wind about 135 degrees, apparent wind generally on the beam. Still forward of the beam on fast boats.
Deep reach. Deeper than Broad reach. Apparent wind will be on a the beam on a fast boat, perhaps 135 degrees on a cruising boat.
Run. 180 degrees, true and apparent.

I started a discussion on a forum here that resolved nothing. Plenty of references on both sides.






Wiki takes my view; not an authority, perhaps, but I'm hanging my hat there...



-----

All I can say is that if I make a course reference it is relative to true wind. How my specific boat requires the sails be set is to me of less importance to the story than telling the reader the direction of the waves and the nature of the sailing. That is enough and it is better related by the true wind than some artifact of how fast I'm moving.

Sunday, September 1, 2013

Long Bridles

Rev 10-29-2013

I'm still working my way through this topic--I think many cat sailors are--so this post is a work in progress.

There are 5 conflicting requirements asked of a catamaran mooring bridle and I have yet to hear of a perfect solution. Partial solutions that work, but always prone to some critical flaw.

  1. Turning Leverage. First, cats need a relatively long triangular bridle to keep them into the wind at anchor. If anchored to the center beam they skate all over, with a bridle they are placid. Legs equal to the beam provide sufficient leverage and allow working from either bow, if needed. Longer legs also place less stress on the bridle (basic statics/trigonometry).
  2. Shock Absorption. Actually, this applies to all boats, but more so to cats as they are more inclined to anchor in shallow water. Waves, particularly if breaking or simply steep, impart tremendous energy that the typical all-chain rode cannot absorb. Folks say the catenary absorbs shock, but only true in deep water with several hundred feet out; in a 50-knot squall anchored in 6 feet of water (60-70 feet of rode would be conservative) the rode is so close to straight--within 1 foot-- that chain has no absorptive capacity. What is needed is a nylon bridle long enough to absorb a wave, that is to stretch 2-4 feet. That will require a 30-foot bridle leg. This is even more vital for monhulls, which see severe impacts if a wave strikes the front beam or bridge deck.
  3. Apex of Bridle Must be Off the Bottom. If a very long bridle is used the apex will be on the bottom during slack conditions, subject to chafe. While this is not critically important in the Chesapeake mud bottoms, with rock or shell it would be. Even on the Chesapeake oyster shells eventually take a toll.
  4. Chain Hooks Like to Stay Off the Bottom. Even the the Mantus hook, one of the most resistant to getting flung off, stayed on when I used a short bridle but frequently fell of when I used a long bridle.
  5. One-size-fits-all Would be Nice. What boat has extra room for extra stuff?

In a recent Practical Sailor Magazine one multi-huller suggested using a long bridle, but anchoring the legs far back on deck, to the midships cleats or behind. The bridle then goes through a turning block and forward to the rode. The legs are thus over 30' long for shock absorption, but the legs between the hulls not so long that the apex of the bridle rests on the bottom. Another experienced contributor poo-pooed the practice, citing extra chafe points and rigging. True enough. He was a monohull sailor, of course.



I thought I would try it for a night.  My new Mantus Hook testing bridle is long enough and the wind was gusting over 20 knots. I was protected from waves but not the wind. It kept the bridle off the bottom.
  • The boat rode well, without any jerking or surging.
  • There was certainly movement of the rode through the chocks during the gusts--4-6 inches in the stronger puffs--proof the stretch was working. Webbing chafe gear seems to work, but anything that generates friction also reduces the effectiveness of the side deck portion of the bridle. Additionally, the line could jump out of the chock in rough conditions. A turning block is the right answer, but it must be well placed. For my boat and circumstances it is not needed.
Food for thought. It looked neat and it worked, but with turning blocks there is really too much to set up nightly and there is no go location for a turning block on my boat anyway. For now, it has become my standard method.

Relocating Jacklines

Formerly the jack lines terminated at the forward beam; simple and strong, but cause a tripping hazard. After far to long a wait, after a suggestion by my daughter, we relocated them to the edge of the tram, where combined with a small back-up plate and the natural strength of the hull flange and trampoline track, there is a natural strong point.

The aft end is still anchored to the hard top railings, the spliced end of the dockline cow-hitched around a center point attachment, spreading the load.

The forward end is lashed (many passes of parachute cord adding up to a 5500-pound line) to a 316 SS bolt hanger. The chafe gear is for UV protection.

Less of a trip problem, equal access, easy to re-tension.

--------------

Why rope instead of webbing, as is the conventional wisdom? Though I've discussed this before...
  • UV. We leave them rigged 365 because we believe night comes every day, the water is cold in the winter, single-handers need to stay on the boat, and thunderstorms give little warning.
  • Under foot? We don't worry about stepping on them because they do not run on the deck.
  • Stretch. We like the stretch of nylon dock line because we have a cat and used long tethers. If we were a mono-hull we would use something lower (but not zero) stretch.
And we use 2-arm tethers. One about 84" and the other about 30". Fit them to YOUR boat.



Wednesday, August 21, 2013

Big Changes...

... perhaps the greatest since getting married.

This morning we are packing our only daughter, Jessica, off to college. It's going to be strange not having my many time hiking, climbing, skiing and sailing partner with me, at least not so often. I'm going to spending a lot more time with my wife, but different time. Quieter time with a different focus. Time to remember who we were before children, consider what changes we have experienced, and decide who we are to become. Seems better than mourning what is perceived lost.

I will miss each age, but the whole point was moving to the next age... wasn't it? Some days I wouldn't mind being 12 again. Except I doubt my folks would have let me sail into the sunset with my wife.

Friday, August 16, 2013

Navionics on a Tablet?

rev. 9-17-2013

While the chart plotter on my PDQ certainly works well enough, it's 1997 tech, the only maps loaded are for the PO's stomping grounds, and the disk and adapter have failed. The base map is +/- about 200 yards and lacks depth and day mark info. But since I'm an old school coast piloting guy, I really never worried over it; I have paper charts, know the Chesapeake fairly well, and it gives lat/long and speed very well. But then I was given a tablet.

I'm not into gadgets. I've got a dumb phone, no I-anything, and I don't text, tweet or Facebook. I blog and that's about it. My daughter thinks I don't understand these things, when in reality I simply don't care... and she does come to me whit computer problems. Go figure.

Simple slide-down mount made from an old car phone bracket and some bits of aluminum and FRP.

And now you know exactly how to find my home slip.


It always occurred to me that I might simply use a tablet when time came to upgrade. Far cheaper than a large screen chart plotter, the cockpit on the PDQ is quite dry, and multifunction. I was given a tablet by my office for time-in-service, so I'm experimenting. It is a low-end 10.5-inch tablet (Coby MID 1065) that lacks internal GPS, and so Navionics (Marine US HD) does not link up with locations. But it does have a very nice map set that is resident in the tablet (not Wi-Fi) with FAR greater detail than the NOAA paper charts, so it has earned a place. On a tablet with internal GPS I think it would earn 2 thumbs up. As is, a solid 1 1/2 thumbs for being free and for how much better a touchscreen makes Google Maps.

Notes August 31, 2013.

I'm drawn to comparing the tablet and marine chart plotter to an smart phone and standard phone. Which is easier to operate if someone ties one arm down and shakes you vigorously by both shoulders? The dumb phone can still be dialed. How many of those menus can you access? can you place your finger in just the right spot to type a text? Can you read it?

Someone suggested "well, you can change the settings." When? While I was still in the harbor? Certainly not out on the waters once it gets rough.
  • Thumbs down for touch screens in rough water. While blasting into 3- to 4-foot square chop on the Chesapeake I found the touch screen completely unusable. Every time I tried to perform any function I missed, slid, or touched several things. I've asked around and numerous sailors feel the same way. At the same time I had no trouble operating the existing GPS chart plotter that depends on buttons with few menus. Hard to miss a button.
  • Thumbs down on small type while underway. Same problem; if the screen is jerking up and down, anything smaller than 14 points is unreadable and high definition means nothing.
  • Thumbs up for navigating small creeks and rivers. With smooth water, all of the touch screen functions and the high resolution have value. Much easier than flipping chart pages.
  • Thumbs up for the Google Earth overlay. Just WOW. However, turn this off while you're navigating; it really slows things down and can cause fatal lock-up (not just reboot but reload).
  • Thumbs up for vertical orientation, at least for the Chesapeake, and perhaps for most coastal areas. Most of our sailing is north/south, not east/west. 
  • Thumbs up for the twin ball and socket mount. Works perfectly, no movement.
  • Thumbs up for the top slide-in mount. Though a boat can be rough, we don't have the same high frequency bumps. Very easy, one-handed. Put the power switch on the top. Make certain the charging outlet is accessible.
  • Accuracy: Better... and worse. While there is better resolution on the charts, some of this comes from user input--crowd sourcing--and some of it is just plain wrong. And this isn't just a matter of sand an mud that might have moved. I visited a small cove where Navionics indicated and 8-foot entrance bar and 23 feet inside. In fact, it has always been a 6-foot bar and about 8 feet inside. I noticed other discrepancies of this sort. Is it glitches or crowd-source data? When I turn "user comments" off the errors are still there. Keep your paper charts.
I think I like it enough to upgrade to a top end tablet when this one goes. But I may still choose to replace the marine chart plotter when it goes, probably for a small screen version with buttons. It is actually rather nice to leave the GPS on a nice big, readable NAV screen while I stroll through possible destination and zooms on the tablet, planning the day ahead of me without having to page through disjointed chart books.

Thursday, August 15, 2013

Harness Creek

With my daughter heading off to college in a week, a last family outing was required, even though or perhaps because the home scene was getting crazy; it seems we are remodling the kitchen in the midst of extending the transoms, doing other boat maintanance, and of all this other transition. I needed a break from endless painting, sanding, plastering fitting.

Initially I had a cross-the-Bay trip to Cambridge in mind, but 2 days of bashing straight into 20- to 25-knots headwinds didn't feel relaxing. So we adjusted and picked a destination that would give us 2 days of broad reaching in the lee of land with few waves. 8-10 knots of boat speed without even trying. Much nicer.


An uneventful trip, which can be nice. A summary:

The Sailing. A moderate winds, 10-25 knots but protected. not intersting navigation; I've been there before.

The Crew. Our newest member didn't contribute much really, but he did keep folks busy. A 3-week old grey squirl found by a friend who was going in for surgery, we had no alternative but to bring the fella along. He hid away in his shoebox, all except for feeding times--sleeping in a fleece blanket, warmed by a heating pad to a perfect 100F. Feeding is no more than a few ml of special formula every few hours, with a longer break at night--I'll get up in the night for a small human, but a rodent will have to just hang tough a few more hours.
The Equipment. The genoa sheet developed an interesting failure, the Kevlar core failing from fatigue while the sheath
remains intact. The thing of it is, and the reason Kevlar core ropes have fallen out of general use, is that the fibers are prone to cracking when repeatedly flexed, such as the attachment to a genoa clew when it flogs during furling. I've used Kevlar very successfully for halyards, where the turns are gentle and there is little motion, but I would never chose it for a sheet or frequently adjusted tackle.

We got home with the bad spot cut out and bowlines. I expect the rope will last at least a few more years.

For the 3rd time, the Mantus chain hook spontaneously disconnected while lying on the bottom during a period of slack wind and tide. We returned from a dingy exploration to find Shoal Survivor anchored only by the chain, at the odd angle to the wind cats take when anchored to only one bow. When the wind came up in the thunderstorm that night, we would have skated all over the cove, possibly jerking the hook out. While I will continue to use the hook during the day as part of a Practical Sailor trial, it will not be used at night in the future. I will be using a girth hitched sling.

The Exploration. In the morning we anchored in Almshouse Creek, just 2 miles away, in order to make a brief visit to the London Town Historic Area, a nice park and garden area on the South River. Interestingly, the main brick structure in the old town--the only surviving building--was an almshouse (poorhouse) for the local area, after the town and the tavern in the brick house failed. This creek, lined with multi-million dollar houses, is named for the almshouse. Ironic. Bet the the houses wouldn't sell quite so well on Poor House Creek.

We also explored the park, the coves, fed the duck, swam, and enjoyed a picnic dinner on the foredeck on a perfect evening. Easy livin'.

And now I must return to work, to kitchen remodeling, and to packing my daughter for school. Sailing is better.

 


Sunday, August 11, 2013

Credit Where Due

While preparing review articles I often get some help from manufactures and vendors. To defend our objectivity we avoid giving citation to those that have helped. However, in many cases these were just good folks, helping out, with no dog in the fight. I no particular order....

Atlantic Rigging, Deale, MD. Some new and old line for testing, and some antidotal expereince.
When asked about the occational practice of powerwashing lines, in their words, "some customers would rather replace a rope because it's dirty than because it needs it."

Canvas Conection, Deale MD. Some advise and some scraps for testing.
They built a new enclsure for me. Best price, on-time delivery, installed on the boat.

New England Ropes. Some new line for laundry testing and lab services (breaking line that we had exposed to bleach).
They actually replaced the first 100-foot donation with another 100-feet of line, after the washer destroyed the first samples. I think they were glad enough that we would publish proper washing instructions and relieve them of some complants.


Potomac Sailmakers, Alexandria, VA. Some advise and some scraps for testing.
I've been taking sails there over the years, for additional reef points, restitching, and UV covers. Always a pleasure to deal with and always timely.

Herrington Harbor North.
Though too pricy for me to keep my boat there, I have used it as my DIY yard for years, as their hauling and dry storage rates are reasonable and they are very DIY freindly. Have they ever made a mistake, over 25 years? Yes. But I've never seen them hesitate for 10 seconds in making it right. When selling my last boat there were 2 tasks (carrying the deck a short distance and lifting the mast onto the trailer) that were made reasonable by 10 minutes help of a travel lift crew; no bill. They've brought me extention cords when I was placed too far from power. They've moved the boat for me when they realized I might get spray from washing operations and I was painting. Once I hit a submerged dredge pipe that had drift out into the channel, damaging my dagger board. They only asked where my boat was. They hauled it, repaired it (and invited me to come review the repairs and offered a survey), and returned it in a few weeks.

Sunday, August 4, 2013

Extended Transoms: The Process


rev. 10-29-2013

I am now the proud owner of a PDQ 34 Altair, the only one, from what I understand. Rather than rehash my reasons, I will refer you to a prior post. Was it worth it? For me, yes, but this is not a small project nor for those not very comfortable with fiberglass. Well, perhaps someone with time to read, fiddle around, and learn, though I suggest learning on something less ambitious first. Perhaps it could be a good step towards convincing you that building a boat from scratch is for the birds, when there are so many good used ones out there.


Preparations

The boarding ladder has to come off (the bolts are screwed into the threaded backing plates, so this is simple). The transom edging has to peal back (secured with polyurethane--not so easy). 500 pounds (as least it seems so) of tools must be delivered to the work site, including many that end up being of no use. The top side of the transom flange requires heavy grinding to produce the 12:1 taper required for bonding (the outside bevel will be ground after molding).


The Mold

A discarded 18-gauge aluminum (0.040 inches) sign provided the perfect flexible form, allowing me to match the existing line of the hull very smoothly, including the sharp turn at the chine (a little manual pre-bending was required at the sharper bends). Extending the form with furring strips allowed it to span the rudder and allowed lines tensioned by secondary winches to provide very firm but easily adjusted pressure, vital to the accurate positioning of the form. However, a ring of self-drilling sheet metal screws (1" x #8 of the sort with the drill bit in the tip--the plain pointed sort would not pull-up properly) placed along the flange was still needed to eliminate all gaps and to insure the form was tight to the hull form. Though originally I had figured on installing a false transom on the form and legs to the ground for support, with the sheet metal screws in place the form became quite rigid and no further bracing was required, even to withstand vigorous laminating roller usage. The form was waxed and coated with PVA mold release; the PVA was almost certainly over kill and I would not use it next time. Keep the PVA and wax away from the flange!


Laminating

Laying up the required amount of triax on the hottest day of the year (100F) was both painfull and a lesson in exothermic reactions. At times my daughter rubbed the back of the form with wet towels and ice while I worked fast. One of my favorite hot weather tricks is to keep the epoxy and hardener in a cooler with ice, so that at least the mix pot does not heat too quickly, and it also helps to keep the pot off of hot surfaces.

Triax seems to be the best choice to build strength and thickness when working with epoxy. Mat has a binder that dissolves in polyester resin, allowing the material to go limp, but this does not happen in epoxy resin. Roving is too lumpy and bonds poorly on its own.The triax wets nicely, goes limp, and conforms very well for its weight on all axis. My source was Jamestown Distributing.

I used 8 layers of 17 oz. triax for the basic lamination, with 3-4 additional 4-inch strips of triax over the joint and edges, sandwiched in between the large triax sheets. A natural lap also created a beam down the beam centerline (I used sheets for the right and left, rather than one sheet, for handling reasons and to better fit up to the existing transom).  In retrospect, this may have been slight overkill, but I've thumped the stern into a dock before and will again, since I back into my slip every time.

Use a grooved laminating roller to squeeze excess resin from the laminate and remove air. It is also very benificial to have a helper during the main laminating step, to mix epoxy and cut glass, particularly if things begin to heat up. If you like to work more slowly, use a slow hardener for this process.

No coring. The complexities and structural compromise makes little sense, to save a few ounces in such a small area with hardware mounting and impact potential.

Drill limber holes. I did not include a leak-prone access hatches, so there needs to be a place for air pressure to go, plus any possible water leaks from the hardware. I drilled a 3/4-inch hole for each extension at the lowest point, sealing the edges (curiously starboard was cored with Corecell, port with mahogany plywood). They have not leaked a drop, and if they do, it will be into a crash tank.


Pulling the Mold

Self explanatory; with just the slightest tug on one corner it falls away. The poorly wetted fabric is in the sections that I was planning to cut away. Somewhat wasteful of materials I suppose, but time efficient.

The form literately fell away. The port form hit the ground  before we could get a picture!




Trimming

At first I feared trimming a bit, since I would be cutting 1/2-inch FRP. However, I found that an 4 1/2-inch angle grinder with an abrasive metal cut-off blade goes through FRP like butter and is very easy to handle, the only down sides being that there is a lot of dust and the cuts must be straight (a series of short straight cuts can approximate a curve, and a grinder with a 25-grit disk makes it smooth). I can't imagine anything much better.

 I have ground the bevel on the outside of the join at this point and am ready to glass that in. The joint should be as strong as the rest of the boat; is is certainly far thicker.


Building the Steps

After bonding and taping, before final fairing

The steps were more like a carpentry project, but with fiberglass materials and methods. I purchased two 2' x 2' x 1/4" FRP sheets from McMaster/Carr and used these for the platform, riser and backing plates. 1" x 1/4" strips were beveled and bonded to the above hull mold in the same manner that cleats would be used to mount wooden shelves, the platform bonded and filleted in place, and then reinforced with glass tape at all joints, inside and outside. The taped areas were ground down both for better tooth and to provide space for the tape without leaving a bulge. All construction is FRP.

Do give the steps enough slope to shed water quickly. I matched the existing slope of the last step and that seems about right.

At first I sought the original PDQ vinyl trim, so that I could match it all the way back. I Googled a bit and learned that some boats reinforce with FRP instead, and that sounded better to me. Stronger. learned that the manufacturer wants a 100-foot minimum order. Perhaps if enough PDQ owners got together, but meanwhile it is simple not available. In the end trimmed the existing molding to fit and called it good. I did not want bumper trim dragging in the water.



Mounting Hardware
Glycerine makes a convinient tap lube that is easy to rinse off.

Without interior access using a simple washer and bolt would not answer. Additionally, since several of the fittings are highly loaded (cleats and bolt hangers for or securing light craft, and the boarding ladder) backing plates would be needed. For backing plates I simply bonded a 1/4-inch FRP plate in the appropriate areas, resulting in 1/2-inch total thickness. In place of a nut I simply threaded the FRP directly, which I have done on numerous occasions. So long as the FRP is greater than 1/2-inch thick (about triple the thickness of a nut) and the threads are well formed, the bolt will fail first. While I could have used nuts, I wanted removability without an access plate. If I am wrong I can always add an access plate later.


While I am a proponent of butyl tape for bedding large items that may require removal (hatches and winches), I prefer polyurethane for smaller items, as it adds to joint strength and helps keep the fasteners tight. The bond is not so great that removability is a problem. On the other hand, 3M 5200/4200 are too expensive, so I've generally switched to Locktite's PL S40 window sealant. Since I began using it 8 years ago, I'm comfortable with its durability in a marine environment. I used to patch a fishpond 6 years ago, and it is still doing fine.

Ready for paint. The trim conformed nicely. Note the inside edge is smoothed for sitting comfort. The bolt hanger (one on each side, only $3) is for clipping kayaks and tenders while at anchor; more compact and less painful to sit on; I heard stories of small cleats tearing very substantial holes in very tender places.

I had to cut 2 shallow indentations in the starboard transom rim for the ladder, to get the deployed angle I wanted. I had placed the step riser at a greater angle than prior because I liked the look better, the step is much lower, and thus the angle is different. With the indentations I got the ladder angle I wanted and the ladder gets side support. A 1 1/2-inch hole saw did a nice job, drilling from both sides.



Paint
The extension mold faired very well to the existing hull lines.
Nothing to disturb smooth flow or to increase transom suction.

Matching is the eternal challenge, made more challenging by stained gel coat. Match the lightest spot and it looks like a suborn clean spot. Match something more realistic and you better never compound the gel coat. Interlux's "off-white" turned out to be a fair match for my stained and faded gelcoat, as though a Chesapeake boat is ever going be without a few tannin stains; my marina is too close to the marsh for that to happen.

Then there is balancing solvent with temperature. Add considerable extra when hot or the paint will dry too quickly to self-level and maintaining a wet edge will be impossible. I started with a new "flagship" brush from West Marine, but went to an  old favorite varnish brush From Home Depot as the brush marks were less; a new brush seems to get finer over time if well maintained. Once you get it reasonably level, don't go back, you will only make it worse; have faith it will level if left on its own. Keep it thin on vertical surfaces and consider tipping off with vertical
strokes when working in tight places or really any time, as i feel like I get few sags that way.

Other than that, pretty straight forward. Three coats topsides, 3 coats bottom paint (normally I would only do 2 coats of bottom paint, but this is a fresh start). No barrier coat is required with epoxy construction.

Don't forget non-skid on the steps--fresh gloss paint is "slicker-n-eel-sh_t," as they say in these parts. Sprinkling coarse salt on a thick cost of wet paint (the salt dissolves in the rain leaving little holes) will take the shine off and add texture without introducing bathing suit shredding grit. The appearance and function is a very close match to the PDQ gelcoat non-skid treatment. A very traditional method, seldom discussed.

I may add some hull graphic or additional striping to further hide the transition, or perhaps simply to highlight her new tail feathers. I haven't decided.

Zoom as close as you like--no sags

Sailing

A few pictures tell the tail. The Results (below) put it to numbers. One thing we noticed immidieatly was that you can now hear the wake from the helm, as it is just a few feet further back. But is is quiet.

Very close reaching at 7-8 knots. The platform goes under a wave now and then, which hurts nothing.



 Broad reaching at 8 knots. Dry enough that I'm sitting on the other side to capture this image. At this point 2 crew members had moved onto the tramp, lifting the stern. Sitting on the port platform (no ladder) underway is very cool, though someone certainly ought to keep an eye on you.





The steps in summary form. I hope you get tired just reading this.
  1. Pull boat and block.
  2. Sand the bottom as needed and prep for bottom paint. Might as well do it at the same time.
  3. Compound  (do not wax)  the last few feet of the boat or you will never get a good paint match (you won't be matching the true color).
  4. Grind off 6 inches of bottom paint in front of transom.
  5. Bevel the inside of the transom flange 12:1 with angle grinder and 25 grit disk.
  6. Remove boarding ladder.
  7. Construct metal form. Wax.
  8. Install metal form. Tighten the lines with the secondary winches. Lots of screws to insure tight fit.
  9. Coat form with PVA, just to be sure. Make CERTAIN you stay a few inches from the flange; the wax will be enough.
  10. Mask the edge molding and the SS handrail. Way up, as epoxy loves to spatter.
  11. Lay-up hull extensions with strips of 17 oz. triax. 8 layers average, with more on the edges, joint and rim. Depending on how fast you build this up the epoxy will exotherm, so be prepared to cool the form with wet towels as needed. If using West Systems, use 206 hardener in hot weather.
  12. Pull forms. Easy. They practically fell off.
  13. Remove mold release agent (water and scrub for PVA, xylene for wax).
  14. Fill bumps left by screws in forms.
  15. Grind 12:1 bevel at seam on outside.
  16. Fill bevel with triax and 6 oz. cloth as needed to fill. About 6 layers. Cloth leaves a nicer surface finish.
  17. Trim extensions to shape (grinder with cut-off wheel). Shape with course sanding disk.
  18. Add 1/4" FRP rim to last 14" of outer edge. Grind to shape.
  19. Rough-cut platform from 1/4-inch prelam FRP. Test fit and mark locations of supporting cleats. Make certain there is enough slope to shed water.
  20. Add any backing plates required for boarding ladder and cleats. Bond with thickend epoxy.
  21. Bond and tab 1"x1/4" cleats with thickened epoxy and glass tape. Short screws can be handy for holding while curing.
  22. Trim platform and place on cleats in thickened epoxy. Smooth epoxy underneath (you will be tabbing over this and so need a fair surface).
  23. Tab in with triax from underside. Not fun.
  24. Add additional thickened epoxy and form filets on all corners and joints.
  25. Repeat same steps for step riser.
  26. More thickened epoxy to smooth joints. Like finishing drywall, but harder to sand.
  27. Grind all transitions smooth. Go for your finished shape at this time, as the glass tabbing will be relatively thin and should not be ground away.
  28. Tape all seams. There are lots of them; both sides, aft edges, platform to lowest step.
  29. More fairing. Start using finer cloth on angle grinder and finish sander.
  30. Paint. 3 coats Perfection using a fine brush and great care. Sand lightly between coats. 
  31. Non-skid on the steps. Coarse salt in wet paint works very well.
  32. Mount hardware. I chose to thread the FRP directly, as 1/2-inch FRP holds threads very well. Seal with polyurethane sealant.
  33. Paint the bottom.
  34. Tape boot top. Replace the whole strip if you have the energy. Xylene and a sharpened drywall knife.
  35. Pay the yard and launch.
  36. Go sailing. Compare numbers with the last time you had a clean bottom (doesn't sound right...).
  37. Write blog post. Share the pain.

The Cost. While I didn't keep a detailed log, the rough consumption was this:
  • 12 yards 17 oz. triax
  • 3 yards 6 oz. cloth
  • 2 gallons epoxy
  • About $1200.00 in total "stuff."
  • About 45 hours labor + 12 hours of helper. I labor at a kinetic pace and I made very few false starts; if you like to relax or if this is new to you it could be double or triple. 
I figure this comes to about $600/ft vs $3,125/foot for the entire boat. If you have to pay a vendor (I got a quote of $7,800) the economics are less appealing. If I count my labor at a standard shop rate and worked  slower (I would have if paid by the hour), I can see how they got there.


Things I would do differently (advice to the reader--a very short list)
  • Use slow hardener if working in the summer.
  • Countersink and fair the screws holding the furring strips to the form. Saves faring later.
  • Mask off the hulls and trim better before starting. I was hot and my brain was cooked.
  • Dimensions: Perhaps 30 inches, but no longer than that for docking reasons. There is no sailing advantage and I'm happy with 22 inches. Perhaps a few inches higher would be drier, and some might prefer to run the outside higher for appearance.
  • Lay-up schedule; no changes.
  • Materials; no changes. 

Higher Sides?

Would higher outboard sides be better, like those on the Seawind extensions? Perhaps the higher sides give a better line and they certainly make the boat look bigger, if that matters to you. However, since one of the primary reason for the extensions was to ease boarding by my elderly parents (and the rest of us when carrying things)from low docks, the higher sides are a non-functional impediment. As for the passage of water and waves, very few strike above the first step and I can see no hydrodynamic reason for the extensions to be any higher. Some mono-hull sailors have argued that sugar scoops make no sense for offshore work at all, but cat sailors have not found this to be true and it is certainly of no concern to the coastal sailor. Making the forms higher on the outside would be a trivial matter, only a little more glass would be needed and the fairness of the sides before I trimmed them down was very good. The difference in labor and weight would be slight, the major concern being more critical paint matching. As boarding/swim platforms and for cleaning up the wake, they work just fine.

Though they are clearly well out of the water at rest, at speed the boat drops several inches into a displacement wave "hole" and further yet if everyone is in the cockpit or aft. Another foot would be good.


The Results
The dingy is lashed to the hull at 2 points.
There are good reasons to cu the inside edge low.
  • The hull form came off the mold true within 1/16-inch of anything I could have planned. Two thumbs up for the sheet metal mold.
  • The finish and detail fairing deserves only one thumb up. I will revise this in 2 years when I haul for bottom paint. But I got a good color match and it passes from 20 feet and closer, perhaps, if your glasses are scratched. 
  • Boarding is greatly improved. This is a major plus for family members with mobility issues. But even for the rest of us, loading the dingy with "stuff" is simpler and boarding kayaks is now a breeze, even in lumpy conditions.
  • The ladder now lies flat on the bottom platform rather than up the steps.I hated having to work around the ladder when it was on the steps.
  • Access to dingy and access to the water. This goes beyond simple boarding. Want to fish with your feet in the water? Wash out a pan? Work on the tender outboard or simply pull/replace the drain plug? Everything is easier.
  • Pitching. Certainly it must be reduced, but controlled measurement is impossible.
  • Weatherlyness. Any reduction in drag, resulting in better water flow over the foils, has to help. The net improvement in VMG is more than the sum of the parts.
  • Speed. Motoring at full throttle we have increased from 7.3-7.4 knots to 7.5-7.6 knots (measured by GPS, average 2 directions, both times with fresh bottom paint). The waterline length increase would suggest about 0.25 knot increase is possible, but since the hull form was not changed, 0.2 knots is more realistic and is what we saw. A small improvement, but worthwhile. The fuel savings at a constant speed to should pay for the upgrade in ... about 120 years.
  • Length vs. speed. Would even longer be faster? I don't think so. I have not changed the entry and the extended transoms are out of the water ~ 2 inches at rest with this 2-foot extension. Other boats with transoms that drag more, or cruisers that load more heavily may find additional length would help. But since the rudders are not typically relocated the affect on handling should be considered before going too long. Though sail boat extension are generally successful, there have been stories of extended power boats that lost steering control.
  • Load carrying. Though most of my sailing to this point has been with a rather light load, when we go cruising I notice the drop off in performance as the water line is pressed 2 inches lower at the stern. I believe the streamlining will help even more when overweight. If I had a very over weight boat or cruised full-time I would go 30 inches.
  • Docking. Since the extensions are 50% out of the water at very slow speeds, just sort of rounding the transom, there is perhaps a reduction in both yaw drag and backing drag. The docking length is not affected, as the dingy still hangs ~ 18 inches past the transoms.We can't feel any difference.
  • Handling. We've noticed no negative affects. More speed means faster tacks (positive), any drag aft should lead towards better balance (positive--comes out of irons faster too), and we haven't noticed any negative affect in quartering seas. It seems like it might be inclined to surf a little sooner, but controlled observation is impossible.
  • Irons. Seems less prone to getting caught and comes out more quickly, simply backing up with the helm over. I think there is clear improvement, the result of length aft.
  • Weight increase. About 35 pounds each, or about 35 pounds per foot of water line (the over-all figure for the PDQ 32 is about 230 pounds). I over built them, but I envision backing into a few docks (note as of 10/2013; I have. the pilings have dents, not the boat).
Was it worth the time and money? For me, yes. Though the process was an exhausting mid-summer exercise (we picked the 3 hottest days of the year--stupid), everything went as smoothly as could be expected with very few surprises and with the level of effort I expected; not my first FRP project.

I always find it fascinating to watch a large pile of money turn into a large pile of glass, epoxy and disposables, and then into some rock-hard shape that we have beheld only in our imagination. Like so many projects, if you do it right the work blends in with the existing and somehow it seems like little was changed, like it was always that way; both the reward of good work and its curse. By comparison, mount some new toy, like solar panels, and in a few hours you can see what you've done, though even then the finer details are subtle or hidden entirely. But do something sloppy and it will be obvious forever.