I've seen some discussion regarding lumber for the keel, and grain arrangement to avoid cupping and warping. Has anyone investigated laying up a keel out of 3/4" exterior grade plywood? It would be just as solid, with no warping/cupping issues, and would save trying to locate decent 12" wide lumber.
You're not getting the length you need and it better be marine ply. Seems like lots more work. Warren
 It seems like we have gone over this a few times in the past, the only way to use ply would be to cover it with glass. Then we get back to the do we glass the keel or not topic. I used std 1x12 pine from Home Depot building my Vacationer the length is not important so long as the joints over lap, I covered the keel ,bottom and sides with three layers of glass. I remember at the time the feeling on the board was not to glass. I did use some 50 2" [attachment=1]screws per sq Ft on both sides of the keel, and installed an aluminum 1"x3" along the bottom of the keel for protection when loading the trailer. After a full season of sailing all seems to be well, I do intend to repaint the bottom this Spring and do a really good inspection. But yes you could use ply but why ?
Hi again, It should have shown 1/4"x 3" aluminum on the bottom of the keel.... Keith
Thank you very much Keith! Photos were very well shot. After all the reading i did on the forum i was asking myself if I'd glass the keel. And I will.
Kieth,
I am curious why you used do many screws? Is there something I am missing? My understanding of epoxy is you only need enough fasteners fo hold it in place while it sets up. I spaced mine about 4 inches apart along the outside edges and only one or two in from the edges where I thought they might provide a more even pressure.
 Morning Terry, I made my keel using 1X12 #2 pine from Home Depot, with Titebond 3. Over the years I have found that 1X12 tends to bow in the width , so as a guard against delamination I added the screws before glassing. So far so good, just finished repainting the bottom and the keel still looks like day one.  Keith W
Keith, That was probably a very wise decision. I had assumed you used epoxy. I am not sure that even epoxy could prevent cupping. I to used quarter sawn southern yellow pine for my keel so hopefully won't cup or bow. Another possible advantage is that my keel is not very deep. It is 4-6 inches along most of it. The deepest spot is only 8 inches.
I used ply for the keel on my weekender. I did so because at the time I wanted to start building, I couldn't find any lumber that wouldn't drive me crazy in the future with all the problems that everybody has been talking about. In other words, the quality of lumber I wouldn't use on a dog house.Â
Using plywood to actually construct the keel was a piece of cake. I scarfed the long boards that were for either side of the keel and laid everything up with epoxy. The only accomodation I made to the plywood was to cover every square inch of end grain with hardwood. I laminated a 3/8 inch shoe over every bit of it embedded in epoxy. I also glassed the keel which was a bit more work than I anticipated, but I figure to inspect the keel frequently, so I'm not too worried about rot. Below all that, I mounted a 3/8 inch thick plastic shoe. To damage my keel now, something sharp is going to have to hit it from an angle. I know I'll feel that and will inspect for damage when she gets back on her trailer.
Al