Idea Drive

I'm always looking for things to investigate, either product reviews or engineering problems.


A few that are in progress.

• Bucket dust collector. I made a trap for bottom sanding dust that goes between the sander and the shop vac, keeping the filter clean. Also good for pumping liquids.
• Tall step disease. How boats have more access issues than they need to.
• Outland hatch covers. I like them.
• Gaffers tape. Good stuff, outlasts duck tape years vs weeks. 
• Mooring. Quantitative testing of the effect of spring lines and such.
• Catnip oil as fly reppellant.
• Aluminum and zinc anodes. 1-year test starting soon, brackish and fresh.
• 
• Spill prevention. A few tools to prevent spills while refueling. So far I really like the shaker siphon.
• Affect of additives on polishing. Some make filtration easier, some make it worse.
• Stitched eye and thread UV follow-up. I'm going to break samples after 2-years in the sun.

 A few in the thinking stage.

•  Boot drier. There are commercial systems and home-built.
• Aluminum treatments (Alodine1201, zinc chromate, TefGel and more. Salt humidity chamber and old mast sections.
• New Stiletto 27 review. They are going back into production!
• Kayak review. Trying to get a line on some inflatables.
• AC installation.
• Seafurl bearing maintenance.
• Climbing mast from a climbers perspective. 
•  

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Ideas? Questions? I've got too much time on my hands and I need to do something with it.

Product Review--Mantus Bottle Opener

As you know, I write serious product reviews. When I read this on SailNet.com I was devastated that I didn't think of it first:

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(from SailNet.com)

Mantus Review

The other day I received some equipment from the guys at Mantus. Note, I have no affiliation. I do have one of their anchors, yes, but this review isn't about their anchor. There are enough threads out there on them. I'm talking about the Mantus bottle opener. It was actually free for a clever begging campaign, so any negative comment on my part is rude, however, there are no perfect tools for boaters; the opener has its faults. The product came well packaged and in a timely fashion for an overseas delivery. After unwrapping the package, I could easily see that it's a beautiful design and fitted well in my hand. Storage would not be complicated which is an asset for any boat owner. It also had a clever loop for a chain to possibly be used as a cool bling bling necklace, but I digress. It worked very well for the first 6 beers or so, but as the evening's enjoyable extensive testing progressed, and interesting attempts to keep notes for this review proceeded, it became increasingly difficult to operate; however, not insurmountable, they were enough however to give me a powerful headache in the morning because I couldn't totally figure out the problem. For some reason, it kept slipping off the bottle tops and wouldn't properly set. After 4 or 5 more beers (I think) it became useless to operate so I went to bed. The tests were inconclusive (actually I misplaced my notes), so it looks like I'll have to do further testing to retrace my steps again this evening. For now though, I am impressed overall with the design and would recommend it to fellow Sailnet members. Thank you Mantus. 

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I'm too old for this particular type of testing, so I'm thankful that younger sailors are willing to step up. I'm not sure the above tester is qualified however; I can't recall any opener failing me at any point, but perhaps I was very determined... or perhaps I just can't recall.



 

Tying-up

As I begin work on a mooring project (related to anchoring--it seems easier to the sailor, maybe, but it's longer term and the boat is unsupervised), I consider what is work teaching. It's easy to point at bad knots--and I will do that--but serious failings are often more subtle. Take these owner's manual drawings for the PDQ 32:

Note: I have BOLDED the lines in each case to draw the eye to the triangular patterns. Perhaps it makes it easier to visualize the load sharing.

Between Pilings. Very conventional, but still there are obvious failings. All of the lines should be nylon, roughly the same size. Some authorities suggest that the springs can be lighter, based I suppose on the fact that the bow-wind and stern-wind loads are lighter. However, in the event of a breast line failure, you'll wish they were full strength.

1. The bows are too close to the dock. There will certainly be slack, to allow for tide and wakes, and this boat will hit.
2. The slip is too small. I'll assume this was illustrator license, but clearly the stern piling are a problem.
3. The bow line and stern line angles are too perpendicular tot he boat. They would take some strain off the springs if the angle were less. Additionally, the boat would be safer if any one line broke.
4. Where does the dingy go (the lines are going right through it)? The answer on the PDQ is to add deflectors down low, inside the stern, to run the lines under the dingy.

There are also many positives. A lot of redundancy, more than seems obvious.

1. Greatly reduced motion and loads. I'm waiting on windy weather to take load readings both with and without the springs.
2. If any one lines break, the boat is still well controlled, depending on slack.
3. With any 2 lines broken, even next to each other, the boat will not hit anything, if the slip is properly sized. I've tested this both with models and full scale.
4. With any three lines broken it may rub on one piing, but will not go far enough into the next slip to strike another boat. With good rub rails, you are probably OK. 

Alongside. Also conventional, with some of the same failings.

1.  Where does the dingy go? Same solution.
2. No fender boards. While not needed on floating docks, they are mandatory if tied beside pilings. 
3. Bow an stern line angles should be greater, in case the spring fails.
4. I believe the springs (alongside only) should be polyester. There is no need to absorb shock and the main purpose of the spring is to keep the boat positioned properly for the fenders to match pilings. Even with fender boards, sliding fore and aft is asking for trouble. As it is, the boat will still move fore-aft a foot or two with the tide, since the spring will describe an arc of a circle, where the radius is the half length. 

The bad thing is that a single failure will move the boat enough to pop a fender out. What Would I do for storms?

1. 2 fender boards. for pilings, lots of fenders for floating docks.
2. Additional springs. Either from the bow and stern forward and aft, or if length does not permit, from the mid-point of the dock to the bow and stern cleats.
3. Additional breast lines But I would not change the angle much; An angles breast line increases the pressure on the fenders in an end wind.

But mostly, this is a good plan. There are no short lines, so shock and tide are attenuated. No single failure is fatal (assuming the slip is a little bigger).

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This advise from West Marine, is just lame:

• The power boat should have springs to both sides.
• The stern lines should be crossed
• The Sailboat should NOT have a spring line anchored to the chain plate or the winch!
• The breast lines should be perbendicular to the dock (less leverage on the fenders.

In other words, not much is right. I sure hope it is a floating dock, but even so....

Check Your Gear

This is climbing gear, failed years ago, but the message applies to sailors. I have cracked toggles, cables, and shackles. These sit on a book shelf, across from my favorite chair, as visual reminders.

Fatigue. In this case it seems clear that the latch pin was fitted a bit too tight, and after some years, started a crack. since the strength of a carabiner is dependent upon gate integrity, this one was retired, certainly only a fraction of it's rated strength.

Open gate strength. This biner snapped during a fall when the gate was pressed open by a bump on the rocks; with the gate open biners loose 50-80% of their rated strength, depending on the design and how they are loaded. Fortunately there was a back-up and there was no serious consequence, just a clear lesson; the gate MUST be protected from even light contact.

Wind, Fetch, Height, and Period

A steady swell is a rare thing for most sailors. We spend most of our time in confused seas, the result of variable winds, diffraction affects from shorelines and bottoms, tidal currents, and wakes. Still, when working through the anchor testing series it was sometimes necessary to predict what I would find at a certain place and time, so I could be there and test what I wanted, when I wanted.

For example, a steady 40-knot squall lasting 30 minutes (fetch is the distance waves could have traveled during the squall, or about 4 miles) will generate steep waves of about 3 feet with a period of about 1.7 seconds. Those same waves generated by a 15 knot wind over a long time would have a period of 6.5 seconds and would be far more pleasant, and 40 knot winds given a long blow will generate mountainous waves I hope never to see; the largest I've sailed in were about 10 feet, and that was enough. I think I could go the rest of my life without winds over 20 knots.

A Poor Solution to Non-Problem

For most of us with all-chain, simply getting the chain straight between the anchor and the gypsy will keep the anchor coming up straight, perhaps with an occasional un-twist (lower and re-hoist) if we have spun. Some like swivels. But then there are bad solutions:

While this gem is only offered up to 22-pound anchors, the leverage  in a side pull, should the anchor get stuck, seems pretty rough on the bolt at the anchor end. Worse, it adds 6 inches more length to the anchor shank, increasing the odds of bending or breaking out.

Raspberry Award.

More Jacklines

Vertical Jacklines

Who says they all need to be on the deck? I installed a pair of vertical lines to deflect the genoa sheets away from the mast-mounted halyard winches (one on each side), around which they loved to foul during tacks. They are anchored to strong points and the line is 1/4-inch Dyneema, selected because I had it and it was non-stretch. At first I was concerned that the deflectors would be in the way, but I soon realized that they were handy holds and clipping points when working at the mast, much better than clipping to the mast base. I can even lean on the tether in rough weather, allowing for better 2-hand work.

Jacklines and Lifelines as Hand-Holds

It is often said that using the lifelines as handholds is a bad habit. While there is truth to this on a monohull (the leverage on the stanchion bases is cruel when hauling to one side from the deck of a leaner), I disagree for catamarans. The difference is that cats do not heel and that most of the motion is vertical. In heavy going cats pitch, and sailors near the bow can be nearly weightless. Additionally, my jacklines are relatively high at the beam, since they are secured to the hard top. Thus, the safest way to traverse the side decks between the hard top and the tramp is to hold the lifeline in one hand, the jackline in the other, and pull up. Not to the side, not push down, but pull straight up such that your feet are held firmly on the deck. There is little bending stress on the stanchions because the load is vertical, and the support is steady rather than surging roughly as the boat moves. Intuitive to a lifelong climber, something may lubbers and sailors have to be shown.

Pulling up (not to the side!) on lifelines may be a little hard on them, but it is easier on me. Not a mistake, but a well-reasoned standard practice.

Probably just a catamaran thing.

Ducklings always Follow Their Mothers

I guess it is a universal rule.

Cay of Sea and tender, Unnamed cove

The Chesapeake Bay is a small world sometimes. This week we ran into friends we had met over the internet, who dock only a few hundred yards away in Deale, but had never met, face to face. Good stuff.

Chafe

Rev. 10-13-2015.

While I am nearly always complimentary of the PDQ and the attention to detail of the designers, everyone makes mistakes. But in this case I can't imagine what they were thinking. It is not just a yard fitting error, since the starboard bow is identical. It's a design error.

For the record, it never did damage either the webbing chafe guard or the line,since the webbing stay stationary relative to the edge, and the rope glides inside. But I still did not like the look of it. A really strong wind could change things. But it does make a strong statement about the benefits of free-floating chafe gear.

With heavy docklines and my normal heavier bridle this little slot between the rub rail and the deck is too small to be accessible and in 6 years has never cause a problem. However, as I started experimenting with lighter bridles for a Practical Sailor article on mooring loads, I found the thinner 8 mm line could slide right into the slot and that the slot is quite sharp, able to slice a line in minutes to hours, depending on the load.

The chafe gear does a fair job of keeping it out of the slot, but I would rather eliminate the slot. My first thought is to fit a block of something into the space, matching the rubber and secured with a screw and 3M 5200. I'd rather not obscure the forward beam bolts.



Rev. 10-13-2015.
While not the prettiest fix--I may trim this to make it purty--this does solve the problem. I cut a rectangle of 3/8" thick mud flap, laminated it to 3/4" thick, and trimmed it to fit the space. I then glued it in with Loctite PL S30. This sealant has virtually the same properties as 3M 5200, with slightly better elasticity. It is also available in white as Loctite PL S40, the only difference being color.

More Active Anode = More Growth?

I read this in a guidance document by maker of lower potential anode material, and I admit it didn't make obvious sense. Then I started soaking a few trial anode/pipe combinations to help develop a test method for an up-coming anode review.

By December it became clear that unprotected copper fouled less, no doubt the result of more free copper near the surface.

Clearly the more active anode has more growth (aluminum on left, zinc on right, same brand).

Why?