Re: Glue, caulk, Strip Planking on small craft, Some Observations

 

To build something like a Katydidn't, at 6 1/2 ft. long, it wouldn't be much trouble to get the strips out of ordinary lumberyard wood, cutting around the flaws. The strips don't need to be perfect anyway. The wood is just a core. You'd put the bad spots between the good parts of the adjacent strips, to keep the shape. It's also kosher to cut out the bad spots and butt shorter strips together when putting them on the boat, but kinda finicky with 1/4" strips, I imagine.

I've got a bead and cove router bit I'd loan to the Boathouse for a strip build.

What was that Elmer's waterproof glue, Cal? I don't much like their "Gorilla Glue" type polyurethane, and I haven't seen an Elmer's "modified" PVA on the shelves. Lots of strip builders just use carpenter's glue, even though it's not water resistant, because it's easy to use. The boats survive fine because they don't live in the water and it takes quite a while for moisture to get through the glass and epoxy. Titebond II and III are as easy to use as carpenter's glue though, so that's what I'd use.

Modern lightweight strip construction is really wood-cored composite construction and doesn't work as intended without glass on both sides of the core. For one thing, glassing just the outside of a light, frameless (the glass acts as the frames) boat isn't a good idea, because if the inside isn't thoroughly sealed the wood can move with changes in it's moisture content, warping the boat out of shape. It's even recommended not to wait very long between glassing the inside and outside because of the risk of the wood moving. It's also the glass on the inside that does almost all the work resisting knocks, bangs, and punctures from outside, since glass is strong in tension, but week in compression. Best to do what the designers say to do...

On 1/8/2020 5:56 PM, Electri-Cal wrote:
First off, I did an 8 ft round bottom dink with old growth cedar cut to just over 5/ 16 ( to allow for some error ) pretty cost effective for a dink.  Used a couple dry 2 X 8 clear cedar boards picked from Jerrys, for grain that laid flat to bend correctly cause I could se it easy.,  NEW saw blade, cur all with a mask to avoid cedar dust, nasty stuff. I ended up with enough to get me well under way,  Then used a small ball and router table to "C" out one side, sand the other to fit that radius, so the edges overlapped and rotated slightly as laid up over a couple bow, and stern frames L left as was, removed one center frame former.  The bead and cove made alignment almost automatic, and was a pretty stiff hull.
I glassed both sides, but it added unnecessary weight, outside is enough, in my experience,,  Maybe a floorboard inner pad for steeping aboard, or not.  I used elmers waterproof for everything except  glassed areas, I epoxied those.  Again I would use lighter than 3 oz. glass and less of it, the hull was really stronger than needed.
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--
John <@Jkohnen>
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