Re: Questions on transom repair 85 16 seaswirl outboard
From looking at the few pics you show of your boat, I would do either one of two methods to rebuild that transom.
The first option would be to remove exterior rubrail from transom towards bow around three feet up each side, enough to get to narrow section of gunwales. At this point on gunwales I would cut cap on each side, unscrew cap in rear, and lift this section off. This will give you clear path to interior transom repair job, and make it so you can actually epoxy layers of plywood, or whatever type material you will be using, together, and then install as one unit. Much easier than buiding transom one layer at a time. Only drawback is, you must do a nice finish job to the cut seam when reattaching the rear cap section.
Second option that may be available to you is this. You may be able to cut and remove those two thin (2 1/4"?) sections of transom side notch areas, like you have the section where outboard mounts. This may allow you to install layers of plywood, if they are cut in half, staggering cuts. It would probably be pretty messy, trying to install epoxy coated plywood to interior coated transom, but it sure would save a ton of labor in the long run.
There may be at least one other option, depending on how high from bottom plywood goes up on interior transom. That would be to install, epoxy, etc., from underneath that cap section. Again, messy, but will save a lot of labor.
Looking at your exterior transom, I see various holes where items were attached. Each one of these holes can be used to pull new layers of wood tightly against transom interior wall with screws. After it all dries and cures, remove screws and fill holes with pigmented epoxy paste. You can even drill more holes if you need. Don't be worried, when you patch these holes with epoxy, they will be stronger and denser than what you are replacing. If done correctly, it willl never ever leak a drop of water.
Good luck, Mike.