Tuesday, November 25, 2008

Bit and pieces

Lately time to work on the boat has been scarce with the holidays upon us and other commitments. Nevertheless a little progress has been made, lately. In an effort to stiffen up the largely flat sections in the aft two compartments, I glassed in some structural members half way between the chine and the rail. Between f124 and f169.5 I tried encasing half of a piece of foam pipe insulation in two layers of biaxial. It ended up looking good, but only stiffened the panel a little bit. Not enough surface perpendicular to the hull panel, I think. Based on that result I glassed in a ~2" wide strip of plywood into the aft-most section---rock solid. I may go back and grind out the foam half-round, but there is a lot more to do in the short term. We'll see...


I also glassed in a sort of sheer clamp along the transom. The 3/4"x3/4" poplar ripped in the diagonal will provide a little more than an inch of surface to glue the deck down which will be good since I won't be able to tape back there.
My main focus is working on the keel. The handheld electric planner I bought has worked a treat thus far. I just requires the patience to only take off a little at a time. Get too aggressive and you will have many evening alternating between filling and fairing! I also got a 30" longboard that has been great to fine tune the shape. I bought a flexible longboard which will come in handy for fairing the hull, but modified to to make it rigid for fairing the keel. At $50 ea. for the rigid and flexible longboards, the modification was a good solution. I will post a pic when I can.

4 comments:

Unknown said...

Interesting result with the foam as a stringer. I was considering doing this (using 1/2 wrapping paper rolls), but your result has made me reconsider. Do you think it was a result of not having enough tape contacting the hull?

Jeff Dalsin said...

TL-

I think the biggest issue was not having enough surface perpendicular to the hull panel. I suppose I could throw on another layer or two of glass and that might stiffen it up a bit more, but I may have defeated the purpose of going with foam for less weight. Plus, plywood is a lot cheaper the epoxy!

Unknown said...

I have just always read that the way you did it with the foam (or cardboard) was the way to go to add stiffness with minimal weight. Hmm. Besides a curved surface like yours (did you use a pool noodle?) I have also heard about using a triangular shared piece of cardboard. Maybe the straight edges (still not perpendicular) would add stiffness and increase the surface area contacting the hull panel.
If the 1/4" ply is the way to go, that's fine with me, I have plenty of scrap pieces. Just curious.

Jeff Dalsin said...

TL-

I used foam pipe insulation (a bit smaller than a "pool noodle"). I was optimistic about the approach since it did a great job of conforming to the curved surface. I thought is might be somrthing to do all the way fore and aft. But alas, back to the drawing board. Perhaps if we could find the same type of foam in a rectangular form, it would work better.

I like your thought about the cardboard triangle, though.

JD