I haven't really wished the transom height was taller in all the time I've had this boat, so I decided to stay with 20" transom, to avoid making a motor project out of my transom repair. Also went with polyester resin, after talking to a few more guys I know that have done this. I'll let you know later if I regret it!
Anyway, I know this will fall short of the works of art I've learned so much from on this forum, but I'm itching to get the boat back in the water. Here's what I got done so far.
I made a cardboard template from an old freezer box.
Bought 2 shts of 3/4" AB marine grade plywood from SPS in Jensen Beach (thanks, fdheld34), cut to size, dry fit, and laminated them together.
Also against the advise of many on this forum, I got advice from others I know and I decided to use polyester resin. I can feel the spears already!
Coated the surface of the core to be laminated to the transom with resin, layed a layer of 1 1/2 mat on transom skin, troweled some thickened resin on the transom skin with a tile trowel, and clamped the core to the transom. I didn't have enough thickener to make a bed all around the core, so I had to add that later. I would have liked to have had more putty on the transom, too. I miscalculated on the short side.
After loading up on cabosil and glass balloons, I made some more putty and stuffed it in the gaps around the core, and dragged a fillet in it for the inner skin glass to lay down nicely. I was kinda surprised how much cabosil was needed to get a decent putty consistency. I used about 1 1/2 cup cabosil and 1 cup glass bubbles to 16 oz of resin to get a good thickness.
Did some grinding/sanding to prep for laminating inner transom skin. Was going to lay the glass today, but it looks like the weather is no cooperating. There's always Sunday