After cleanup, the next job was to rebuild the transom. The outer skin, although it had a lot of holes, was in good enough shape to re–use. The previous owner had done a good job removing the wood core and grinding the outer skin flat.
I made a transom template out of craft paper, and used it to layout and cut two pieces of 1” Coosa Bluewater 26 for the core. It’s a very cool material. Of all the core materials I considered, Bluewater 26 has the best compressive strength, almost as good as plywood, and weighs about half as much. And it holds a screw much better than structural foams.
I decided to try some vacuum bagging, and so far the results are very good. To complete the transom core, I thickened some epoxy resin, glued the two pieces together, and wrapped them in a vacuum bag to keep uniform pressure on them until the epoxy cured. It worked great and was much easier than conventional clamping.
I also wanted to vacuum bag the core to the transom skin. I cut two layers of 2415 to go between the core and the outer skin and got my vacuum bag ready.
2415 wet out:
Thickened epoxy applied to the transom core:
Vacuum bag in place with some screws and clamps just to make sure:
And the core in place after debagging:
Before laying up the inner skin, I cut the engine notch in the transom core.
That's it for now.
Dave