ideas for lightweight thwarts

[Alanboc1]

Recently removed the vinyl gunnels from my Caption. Milled ash gunnels a wee bit under factory specs and made the existing thwarts more Kaz ish, for a savings of 9lbs. Because the thwart bolt holes are now a bit off, I really need to remake them. Got to thinking that it would be fun to try and save a few more pounds with some square stock aluminum tubing or other non-wood store bought item. Any ideas for a readily available, reasonably inexpensive product that might work?

[JFC]

I've thought about using 3/4" diameter bamboo for thwarts. It's hollow and it's plenty resilient. It's also an invasive species around here, so replacing waterlogged thwarts wouldn't cost anything.

[PAC]

Find a broken composite hockey stick to see if it matches your needs. Very Canadian too!

[clt_capt]

So an old Carbon Paddle shaft works great - If you don't have one, you can order graphite tubing here and cut to length... http://www.mudhole.com/Rod-Building/Han ... g-0-920-ID" onclick="window.open(this.href);return false;

[Bob P]

I use 6061 aluminum tubing, (usually 1" OD x .065" wall) but I can get it through work for under $3/foot. Otherwise, McMaster Carr is more than twice that much.

[ezwater]

I inherited a bunch of sitka spruce from a biplane builder. Because it was necessary to epoxy and varnish the spruce, they being much less resistant to weathering than the original ash thwarts (MR), the weight savings was about 50%.

Spruce, and douglas fir, also also are more susceptible than ash to rotting when water gets between the mounting screws and the drill holes. One way to deal with this, while one has the epoxy out, is to work some epoxy inside the holes. I then use plastic drinking straws as additional liners for the holes. Seems to have worked well.

Thwarts may be subjected to stress along their length, for which aluminum, spruce, what-the-heck, titanium, work well. As for carbon tube, it will take some extra work to set up a mount at each end that will not expose carbon' fragility. (I recall their being at least one supplier of carbon round and rectangular stuff.)

Thing about ash, when Uncle Bozo steps right on the center of a thwart in the process of boarding, ash is tough. I can see aluminum thwarts bending beyond recovery with such an entry. Spruce should make it OK, if one avoids knots or grain runout.

[vzap]

If the only thing bothering you about the existing ash thwarts is the former bolt holes they can be filled with a good quality epoxy such as west systems epoxy. Aluminum will not flex properly and will bend beyond repair much more easily than ash. Carbon fiber is pricey and may prove to be difficult to work with. Let us know how the project turns out.

[Alanboc1]

The bolt holes were a problem because the 2 different width gunwales caused the holes to be right next to each other. It seems like they could "fail" into one elongated hole. However, I found extra ash thwarts and traded them for the ones in questions and rear and used the problem ones to replace the little ones under the deck plates (same bolt hole problem). That just leaves the center thwart which has a foam pillar coming off the bottom, the top of which makes a great carry yoke. Just need to redo that one and the boat will be ready.

Next question!? Ideas for light material, plastic or otherwise, for a OC Slalom regulation bow deck plate. I have used storage tub lids on my Ocoee but it had to be done in two pieces and tends to buckle in the sun. Plan to check out a plastic supply company in Missoula the next time I'm there. Hate to buy a large sheet for such a small project though...

[Trex]

Next question!? Ideas for light material, plastic or otherwise, for a OC Slalom regulation bow deck plate. I have used storage tub lids on my Ocoee but it had to be done in two pieces and tends to buckle in the sun. Plan to check out a plastic supply company in Missoula the next time I'm there. Hate to buy a large sheet for such a small project though...

There is a company on ebay that sells abs plastic that is used for vacuum forming and outdoor signs. I've used some that is textured on one side and shinny on the back for deck plates and after a bunch of years it still looks like new with a squirt of 303. They sell scraps or ends from jobs so a variety of sizes and thicknesses appear at different times and is way cheaper than buying a whole sheet. Try searching ebay for "plastic sheet"

[Mike W.]

I laid up some Kevlar on a sheet of plate-glass. At the bottom edge I hot-glued a piece of tubing & rolled the Kevlar around it (think cockpit rim). This put the curl at the end of the new deck-plate to shed water. I think the regulation is maximum 1" above the gunnel. Once it cures, cut it to fit & screw it on. If I were ambitious, I would have put 3 curls in it. I'll see if I can find photos & post later.

[vzap]

Excellent idea. What tubing did you use? I'me guessing the tubing was removed after the epoxy set up?

[Fleetwalker]

I just made a deck out of Lexan (polycarbonate). That's different and I believe much more impact resistent than acrylic, although they both tend to get lumped together as plexiglass. I contact cemented ethafoam to the top for water diverters. The lexan didn't really think much of the contact cement, so I then used gorilla glue. It's extremely light-weight, although probably not as light-weight as kevlar. On the other hand, a transparent deck is pretty cool looking. Depending on what size you need, though, lexan can be expensive.

We'll see how it holds up in the long term, but it seems to be doing pretty well so far.

[cheajack]

So why not ABS?

[vzap]

ABS is difficult to come by, especially since it is no longer made. Lexan etc. is readily available. I like the idea of using Kevlar (or fiberglass mat or carbon fiber or a combination of the two) for deck plates.

[Mikey B]

ABS no longer available???? I use it most everyday at work. We have no problem getting sheets in 1/16", 1/8", 1/4", and 3/8." Any plastic supplier should have it or access to it.
I used some 1/8" lexan for deck plates on my last boat...cool looking and takes bends well for curvature of hull, but driving at night with the boat on the racks gives some interesting glare at times