Monday, August 18, 2014

Dual Rod Holder From Scraps

Or rather from a stern rail motor mount that the the PO liked but I had removed. In my mind, either the engine should be able to stay on the dingy or...
  • The davits or hoist is weak. Upgrade.
  • The engine is too damn big.
  • The dingy moves too much, in which case it should be triced-up.
  • The dingy is vulnerable in rough weather. Not the case on most catamarans, since the davits are forward of the transoms.
The mount has been resting in a might-need drawer for 6 years but now enjoys new life.

It's primary purpose is to hold my 2 mini-outriggers (2 x 6' outriggers give me an effective beam of  26 feet, easily trailing 3-4 lines without tangles) while not trolling. They can't left in place during docking, and placing them in the outboard rod holds inhibits easy boarding and blocks the holders for other uses. I find rod holders handy for other things as well--boat hooks, walking sticks, gaffs, oars--so i can never have too many.

I dislike commercial holders since they only grip the rail without twisting if tightened so much they scar the rail. This never will, since it uses an up-right for bracing.



Construction was simple enough. I had to slot the back to accommodate a brace. The 2" SCH 40 pipe is attached with counter sunk #10 machine screws. In the background are a pair of kayaks lashed to the top of the davits, the most convenient storage space.


The lures are home-made too.

Friday, August 1, 2014

Eco-Trash

(I borrowed some of this from Windborne. It seemed important to share.)

I'm all about eco. I work for one of the largest recyclers, have built multiple re-cycling and recovery plants, and have invented new processes. But I'm not in favor of mis-labling or eco products that don't meet specifications or perform.

This is NOT mineral spirits.


 This is an emulsion blended to comply with west coast VOC rules. What it is good for, I have no idea.

If it were mineral spirits, it would comply with ASTM D235 (the defacto definition of the term), which it does not in many ways. Basically, FALSE LABELING.

Kleen Strip does make mineral spirits. They also make odorless mineral spirits, though plain or rule 66 mineral spirits are better solvents (the KB value of odorless MS, a measure of grease solvency, is only half that of regular and rule 66 solvents, which matches my experience). All of these meet ASTM specifications and can be used to thin paint and clean-up petrol based caulks and paints.
            
                                   Klean-Strip Mineral Spirits, Gallon

 ASTM D235, Type C, class C
* Petroleum-based.
* Clear, nearly water white (25 units is very nearly perfectly clear).
* Does not contain water (300F initial boiling point).







Tuesday, July 8, 2014

Use It Up, Wear It Out, Make It Do, or Do Without

I think these are done. West Marine, don't last too well, but I like the fit best and I have tried many.



From later that evening; un-named cove, far up Harris Creek. Even on July 5th, a narrow and unmarked entrance keeps this place private.



Sharp's Island Light. The winter ice pushed it many years ago. It is no longer an active ATN.


Just a nice over-night cruise, me and the wife. A nice breeze and no unpleasant surprises... other than forgetting to fill the tender gas tank. But we weren't far. And no jellyfish yet, not where I've been, the up-side of a brutal winter.

Friday, June 13, 2014

Freshwater Tank -- Are Bugs Swimming the Back Stroke in There?

According to the plumbing code and AYBC, there should be a screen on the freshwater tank vent to exclude mosquitoes, other bugs and reduce dust. But many builders, including PDQ, leave these off.  On the PDQ 32 the vent line simply goes up and then down through a mushroom fitting under the bridge deck. Yup, I've seen bugs in there, so while I was up-grading my water system, I decide to fix this too.

Clean, huh? Though a strainer won't stop bacteria, it will reduce convective airflow.

The solution was to splice in a simple strainer. The code calls for 16 mesh, but no-see-ums are known to crawl through that, and 50 mesh is common anyway. This strainer is large enough to manage any air venting flow and serve as an over-flow too, though when filling fast, water will back out the fill even without the strainer in place.

Shurflo 255-323. Be warned, PDQ used 1/2" hose on 5/8" barbs. I stayed with the 1/2" hose (cleaned out the gook with a 1/4" rope, soaped up and fished back-and-forth a few dozen times--tie knots in the ends while you're scrubbing) and used a little K-Y to get it back on the 5/8" barb after cutting a fresh end. Great stuff for working with hose.

The PDQ is a catamaran and the pressure water system is located on the bridge deck, between the hulls. Thus, the tank vent actually discharges down, through the floor, about 20 inches above the water line.

A 15 minute fix. No more bugs. Fewer bacteria and mold spores. Mostly self cleaning, every time I over fill the tank, but also easy to clean and easily accessed. I suppose I should clean the tank one last time, but the new filter is doing great.

Catamaran Slip for Cheap in Deale

 



Why catamaran? There's only about 5' of water and about 3.5 at extreme low tide (soft mud bottom). But there is room for 16' beam.


The previous boat was a Gemini.

Phipps Marina
Calvin Phipps
615 Phipps Road
Deale, MD 20751

410-867-0299

An earlier post has additional detail.

Monday, June 2, 2014

Drinking Water Filtration--The Short Version

rev. 6-21-2014

In the midst of researching a 3-part article on water treatment and filtration for sailors I decided to apply what I'd learned to a simple up grade for Shoal Survivor. I'll explain a little--if you want the really long version, it will take 6-months for all of the testing to conclude and for the articles to be published.

The way I look at it, there are 3 parts to the clean water quest:

Filter the incoming water. Skip this step, even with potable water, and you will build solids in your tank. Pipe scale will shed, harmless bio-films in distribution piping will shed, and dockside hoses always grow algae. Build up solids on the tank floor, and disinfectants and the residual chlorine in the tap water can't reach the bugs underneath. Given time, biomass is food for bugs, the tank will be come gross. I've even seen lines plugged. My choice? First, run the water for a few minutes to run the junk out of the hose, perhaps rinsing off the dodger; it needs it anyway. After that, I like the Camco RV filters which simply screw on the end of the hose, $10 from Walmart. The marine store stuff is the same for 2-3 times the price. I put a 4" extension on the outlet so that it hangs easily in the fill pipe.

What about the fact that the carbon filter will remove the beneficial chlorine residual? Opinions vary, but ...
  • We've used these for 10 years and never built any biomass in the tank. If the tank stays clean and the carbon removes most organic material, their not much for the bug to eat.
  • The residual is not going to last more than 24 hours anyway, and...

... Based upon testing (mine), the hose end filters only remove about 10-20 % of the chlorine anyway. The flow rates are simply too great to give the residence time needed for real removal. Honest, it's a hoax, but we're conditioned to buy carbon. Get some aquarium test tapes and run your own tests. You'll be stunned.

    (And don't EVER put glycol in your tank to winterize. It will ferment, it will smell, and there is more than enough food to clog lines. Empty the tank and dry it. the glycol goes ONLY in the pipes. In the pipes it must be installed at sufficient concentration to serve as a biostat (pH >9, >25% glycol). If the winterizing solution pH is less than 9, ad a touch of borax to bring it up. the result will be an effective sterilizing solution and little or not need for spring cleaning.

    Disinfect the tank. Honest, I skip this step, as I have faith in US potable water, faith in my immune system, I don't like chlorine, and I have an NSF 53 certified filtration step downstream. I also clean the tank every fall, before drying it out for the winter, I have always filtered the incoming water, and the PO filtered incoming water (judging by the spare filters and the clean tank and piping). But if you have less faith or are traveling outside the US, the EPA/WHO/convensional wisdom answer is the 1 tablespoon of houshold bleach/gallon is about right, depending on the water (a teaspoon is enough for water with low bleach demand or with any existing residual). That number is based on rather dirty water. For good tap water, 1 teaspoon per 20 gallons is enough to refresh the residual.

    (And make certain the tank vent is secured. Plumbing codes required a 16-mesh screen and a down turn protected from dust, but many boat builders just leave an open pipe--PDQ did. If you look closely, every so often there will be stink bug doing the back stroke or the bones of some no-see-ums on the floor, decomposing. And while your about it, make certain that seawater can't find its way in. Secure the vent.)

    Filter the water prior to the tap. Even if you have followed all of the forgoing, something could have gotten past and the bleach will dissipate in a few days. This is the business of today's post.

    Just how big are microbes we are trying to exclude?

    Organisms Size range (μm) Example (size in μm)
    Cysts (NSF 53 filters                                 4-14                                     Cryptosporimium  (4-8)




    Prokaryotes
    Bacterium: typical rod 1.0-0.5 x 1.0-10 Pseudomonas aeruginosa (1.5 x 0.5)
    Bacterium: typical sphere 1.0 diameter Bacillus megaterium (7.6 x 2.4)
    Eukaryotes
    Fungi: filamentous
    Red Tide
    8-15 x 4-8
    5-75
    Mucor hiemalis (8 diameter)
    (disolved toxins may be present in red tide)
    Fungi: yeast cell Saccharomyces cerevisiae (29-49.1 μm3)
    Alga 28-32 x 8-12 Chlamydomonas
    Viruses (NSF P231 filters)

    Virus 0.015 x 0.3 Poliovirus (0.03 x 0.03)
    Tobacco mosaic (0.02 x 0.3)
    While cysts, fungi, algae and some bacterium can be filtered out with mechanical filters, viruses require either adsorption mechanisms which are hard to define and fade as the cartridge is spent, or membrane filtration (RO through ultra filter). Several carbon block filters have been upgraded with a membrane on the inside, achieving NSF P231 approval (microbial barrier, tested with real bugs to block everything).

    How are nominal and absolute filtration performance defined? There is no agreed upon standard, but generally speaking, nominal filtration requires 70-98% retention and absolute filtration requires >98% retention of inert test particles.

    I could consider UV sterilizers (too much power) or RO (they waste about 4 gallons for every gallon produced and they leak bacteria anyway), but I'm not nearly that paranoid. I've had no filter on the boat for many years, and I drank out of some real mud puddles in my backpacking days without ill effect.

    I could consider the Seagull filter($600-$1000 for a filter--they are completely out of touch with the market) or the equally effective Microguard by Pentek ($129 complete), or better yet, the Pentek DVG-50 (NSF P 231 certified, $131 complete), which are based upon less expensive standardized parts. Both are well tested and rated to remove cysts, bacteria, and viruses. The Seagull filter just costs more. But US coastal sailors don't need either.

    My choice? I like carbon block filters , available in 0.5 micron nominal filtration. They will easily stop of protozoa and cysts, >98% of the bacteria, and >90% of the viruses. True, viruses are smaller than 0.5 microns, but many are attracted to the carbon surface by electrostatic forces, just as other chemicals are adsorbed. Many bacteria and viruses are attached to larger particles and are removed in that way. Although removals vary according the referenced data source, by the combined mechanisms the reduction is still material. WHO has documented 98.5% reduction of bacteria and 88% reduction or viruses by simple sand filters--a depth filter with similar mechanisms and much larger pore size**.  Granted, it may only take one organism to infect you--I'd worry about that traveling in some areas--but not in the US. In fact, testing by both Seagull and Nano Carb support that virus removal is much higher than removal of equivalent sized inert particles, which is how Seagull gets to its claims. This little miracle is only $25 including the housing and replacement cartridges are available through many sources. The time to install? About 15 minutes.

    We later switched to a 10" filter to get more flow--the Pentek CBC-5 was OK for drinking, but slow when filling pots and washing dishes. We switched to the Pentek Floplus-10, which is NSF 53 certified for cyst removal.

    (A note to PDQ Altair owners: that big grey carbon-reinforced beam crossing the forward end of the salon bench is the mast compression beam. Do not drill holes in the flange.)



     This universal housing from Pentek (158203) was $11, the 0.5 micron carbon block cartridge (2 x 5 standard, Pentek CBC-5) was $10, and the fittings were left behind in a bag by the previous owner. It does reduce the flow at 30-40 psi (standard for boats) from a thunderous 4 gpm that splashed all over, to a somewhat slow 0.7 gpm, about like the refrigerator dispenser at home. I will upgrade to a 10" cartridge next year--my original installation spot did not have room, but a 10" housing will fit hear), which will give twice the flow--all I can actually use without splashing. I elected to filter only the galley tap. Pre-filtered US tap water, with pre-filtration and other best practices, is more than adequate for showers. Do place any filter on the pressure side of the pump; the pump will cavitate trying to draw through a carbon block or any other fine filter media.

    The result? When finished we did a blind taste test with 5 sailors along the dock; not one could distinguish the tap water from Deer Park bottled water (based upon mineral content analysis, the two waters are very similar). For the coastal US sailor, we have improved the taste as far as possible, and reduced the biological risk by at least 3 orders of magnitude. I feel I've reached beyond the point of diminishing returns clear to the point of no return. My feeling.

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

    I will be pressing the research further for the benefit of international travelers. Recently a major manufacture developed a cyst/bacteria/virus cartridge with the same ratings as the Seagull... that fits in a the same $15 housing. For the skinny on that you will need to buy the magazine. Still, the further I journey down the rabbit hole, the more I am certain that microbiological barriers will always have limits. Even ROs get minor leaks, UV lamps can be shaded or fouled, and the downstream plumbing can become infected. Chlorinate the water and get you immunizations. Belt and suspenders, when you cannot be 100% certain.

    ** http://www.ncbi.nlm.nih.gov/pubmed/21974872

    Up-date 6-24-2014: I upgraded to a Pentek Floplus-10 because filling pots with the CBC-5 was a little slow. This filter is also NSF 53 certified (removes cysts); It most probably also reduces bacteria and virus almost completely, but it not certified for this purpose.

    Saturday, May 31, 2014

    RO Water--What Are We Missing

     (This is a work in progress. I'll be back)

    There's been a lot of talk on the web about distilled water and RO water being bad for you, leaching minerals from the body, cause heart disease and all that. Although we filter out most of what we read in the tabliod press and web, perhaps there is a kernelof truth, hear and there, accidentally, it seems. As I begin researching drinking water filtration for a serice of up-coming articles, I find there is substance to to concern over the lack of substance in pure water. While I'm not a health researcher, there is enough scholarly work out there by respected organizations to take seriously. I like reading things from the World Health Organization (WHO).

    WHO Symposium on Low-mineral water.
    WHO paper.

    Please read these at length. Google strings with "drinking water," magnesium," and "calcium." Try to read between the fluff and ignore all sites that are selling something.

    There are many concerns; the three that seem best suported by science are:
    • Heart Disease. A sortage of magnisium is well correlated with certain forms. Also stroke.
    • Kidney Stones. It seems that dietary supliments increase risk, while calcium in the water decreases the risk. Differernt absorption mechanism.
    • Heavy Metal Absorption. If there is enough calcium in the system it out-competes many toxic materials. In fact, precipitation with lime is the basic industrial treatment for most heavy metals.
    It seems all of that traditional stuff about healthful mineral waters had substance. Funny how that happens. Funny how your parents get smarter over the years.

    What does this mean to the sailor?
     

    Even though single-stage RO water (typical sailboat water maker) is not ultra low in Ca or Mg, it is considerably lower than most surface waters and lower than the general guidance available to us. I'm not sure what this means at a practical level. If you swim enough swallow a few mouthfuls of seawater, that's actually a good thing (a few percent seawater will solve the problem). Bottled water helps. Supplements may, but a dash of seawater in the cooking is simpler!

    For coastal sailors I think the message is clear; using dock water with some on-board treatment (I'm researching that) is a better bet than running a water maker.


    Monday, May 26, 2014

    Jacklines, Tethers, and Why Monohulls and Catamarans are Different

    Often I post just to help order my thoughts. Some comments are posted and some come by e-mail and are not posted. They all help.

    I've posted on tethers many times, always with caveat that my views were catamaran-specific. Now I have begun with actual drop testing, with an eye towards a published article, and solutions must be more universal. Or at least we need solutions for all boats and all uses.

    A few of my notes. Scary if you can read them.


    The crux is figuring out where sailors actually fall.

    The bow, catamaran. On a cat the bow is wide and you should be on the windward jackline, even if it is long. If very rough and I need to lean out to add something to a clew, I've been known to clip both the leeward jackline with the short tether and something else with the windward line (the windward line will not allow me to lean out). If you do happen to go over, there is no bow wave trying to suck you under and drown you; the hulls are too fine for that. Upwind, waves can come over and wash you around, but a tight line to the weather jackline manages that, and falling on a tramp doesn't hurt. Getting thrown forward is the greater risk, as the boat stuffs a wave and slows suddenly; the cure is to terminate the jacklines some distance aft of the bow, just as they terminate forward of the transom. A clipping point in the center of the tramp is often handy, as many cats lack a forward lifeline, and on many boats the lacings are strong enough and serve very well. Lacking that, adding several strong sewn points 3-5 feet aft of the forestay can be logical and simple. Because the tethers are long, stretch is needed to reduce impacts, but only when clipped to a hard point; jacklines provide cushion. Falling off the weather side is managed by running the jacklines well inboard--we've got wide decks.

    Getting lifted off the deck is also a problem. Catamarans commonly experience negative Gs up front, and the best answer is to have a jackline you can pull up against, keeping the feet on the deck. Again, the jackline should be well inboard, since the lift can throw you to windward or leeward. Again, a hard point on the tramp near the forestay is handy; when kneeling near the forestay it is common to float upwards.  For the longer tether leg, shock absorption is nice; I've been thrown 12 feet before, airborne from the cabin roof, landing on the tramp. Between the give of the tramp, tether, and jacklines, not a bruise.

    Catamaran, aft. The risk here is simply falling off the back, and stumbling cause by a cat's quick motion. Since the tether is clipped to a hard point, there is no shock absorption, and the tethers are long. Getting swept by away by a wave is a minor risk on most cats; forward, yes, but not in the cockpit, not ever. The boats move over and away from waves. However, tethers are needed when working outside and aft.

    Monohull, bow. The scary fall is to leeward, under the bow wave. Folks have drown there. And thus, a quick release is required, something of much less interest to a cat sailor. The answer there is a short working tether to a fixed point to weather, and a secure grip. It gets skinny up there, something cat sailors don't face.

    Monohull, aft. All documented tether failures have been in the cockpit. The helmsman was stuck by a wave, thrown the width of the cockpit, and lacking any shock absorption (clipped to hard point by a static tether), overloaded the system. Broken ribs and other injuries due to tether impact forces were involved. There are 2 answers to this problem: clip short and use a dynamic tether.

    Climber's bolt hangers provide solid, simple, inexpensive hard points.
    Short, working tethers are important, particularly for boats racing in extreme conditions. Very few falls are documented while people are moving; they are holding on. It is when they get to the work station, take their hands off the rails and focus on the task, that they get thrown. Thus, there should be a good anchor for every station, located such that the sailor cannot get thrown. On boats prone to stuffing the bow--some cats and some sport boats--a tether from behind may be prudent.The new AC cup boats have a tether requirement, specifically directed at stuffing a bow when bearing off. Keeping sailors on-station can prevent a capsize, since they can still do their job. The personal tether must have a short leg, or a fixed tether can be provided at each station.

    Dynamic tethers are another part of the answer. ISO standards now required a drop test that should create nearly unbreakable tethers, but they may break the sailor in the process (unlike climbing drop tests, they did not specify a maximum impact force). I'm still using 8mm dynamic rope tethers, which are considerable lower in impact and tougher (can absorb more impact) than ISO  tethers, but they have one drawback; the rope can roll under foot. I would love to find a webbing with required stretch properties, but I'm not certain it exists; the weave may prevent that.

    ----

    There are other issues.
    • The best quick release.
    • The quick releases must be accessible when the PFD is inflated (most are not).
    • Harness design. The ergonomics are terrible, but there is no practical test method, and short of a full body harness, no good way to transfer the load to a body without damage.
    • Where you you park the spare tether leg clip when not in use? Don't clip it to your harness, or you will have no release. But most tethers provide no alternative. My advice is to add something.
    • Folks don't like tethers, particularly if there is crew on board.  But is the crew skilled enough to get the chute down and get back to you? Hmmm.

    ---------

    So what are your MOB concerns? Where can you take a hard fall on your boat? What have you witnessed or read of? We need data to design solutions. 

    Monday, May 19, 2014

    Speed Polar, PDQ 32/34

    Several years ago, after I adapted to sailing my new-to-me PDQ 32 fairly well, I set about developing a speed polar diagram, to help me better understand how she could be sailed to best advantage. I'm a cruiser, not a race, but I like to get where I'm headed. As an engineer, I can't relax on a boat that is not well-trimmed. No, I'm not a trim and grind racer--I'll set things and let the autopilot keep her steady. But I like things set properly.

    A speed polar will never be right and never be finished. Most properly, there would be a family of graphs, one for every combination of load, sea state, and bottom condition. This is just sort of average for me, with a little growth on the bottom, a tender on the davits, family, a mix of new and old sails, and fullish tanks. If you're a little slower, perhaps there is a sail adjustment that will perk things up. If you're a little faster, good! If you here of a speed several knots faster than what is here... I doubt it.

    And if all of this is confusion and frustration, turn the page and don't bloody worry about it. There are days when I can't hit these numbers--perhaps a foul tide or sloppy wave conditions--and it just ain't worth stressing over.

    Speed and course over ground vs. true wind speed. Where the curve ends the heeling force is too great for my comfort; sails will stretch, sheets must be out of the self-tailers, and someone experienced stationed on the winch.



    Apparent wind speed at true wind direction vs course. This is the partner to the above graph. I generally reef when the apparent wind is over 21 knots up-wind, and 10-15 knots off the wind, depending on the sails and waves. I'll reef earlier if I simply don't feel like working so hard, am single handed, or if the weather seems changeable.

    And for those of you with PDQ 36s, I pulled this from a 1991 Multihulls test. I can't vouch for the circumstances, but I'm pretty sure she was factory prepped, fresh paint, empty tanks and no junk in the lockers, no dingy and hard top. Cheating, in other words. A little more weatherly (the jib is in closer), a little faster in heavy winds, and probably just about identical everywhere else when carrying a load.I also clipped the PDQ 32/34 curves where I think cruisers will reef. They did not. For the non-racer, pressing canvass that hard is just asking for stretch.


    For comparison, the speed polar of a typical 41-foot cruising monohull (NTP 41). A different shape curve, weatherly in lighter winds, but slow in comparison in a breeze. An 8-9 knot speed limit; that just when it starts getting pleasant!


    Sunday, May 4, 2014

    The Other Chesapeake

    A year or so ago I started collecting my thoughts for a different sort of Chesapeake guide book, one focused on small places, kayaking, and the stuff cruising sailors often miss. Well, here it is, a work in progress that will remain FREE. I hope you have as much fun with it as I had researching the other Chesapeake with my daughter (lots of kayaking, fishing and generally fooling about).

    See the link on the right side of the toolbar, above.

    Slaughter Creek.

    DIY crabs on Tangier Island.

    Go find it!