Replacing a transom on an aluminum boat

[Comoxsam]

Hello gentlemen,

I know there are a million different ways to do anything but I would like to hear some thoughts on the best way to replace a transom on an aluminum boat.

1. Material - I've read different things about exterior grade plywood and marine grade plywood. What is the difference? Do they both need to be sealed? Is one better than the other?

2. Laminating - Two pieces of 3/4" plywood laminated together seems common. What is the best method of laminating these pieces? Type of glue? Type of screws?

3. Sealing the wood - If you are going to seal the wood what is the best product? Epoxy? Fibreglass resin? Brand names? What is the best method? What is the best way to seal the holes where the motor mounts etc?


If you were going to replace a transom on an aluminum boat and wanted to do it right, how would you do it?

 

[jasoutside]

Re: Replacing a transom on an aluminum boat

Hello gentlemen,

I know there are a million different ways to do anything but I would like to hear some thoughts on the best way to replace a transom on an aluminum boat.

1. Material - I've read different things about exterior grade plywood and marine grade plywood. What is the difference? Do they both need to be sealed? Is one better than the other?

Hotly debated topic! Marine grade is BEST, and you'll pay for it (must be sealed). Exterior grade is absolutely fine (as is MDO) so long as it's sealed up properly. Many of us have been using Arauco Plywood and it's a great compromise. Just about MG quality at 1/2 the price.

2. Laminating - Two pieces of 3/4" plywood laminated together seems common. What is the best method of laminating these pieces? Type of glue? Type of screws?

Titebond III Waterproof, PL Premium, Gorilla Glue, thickened epoxy, straight epoxy - all very acceptable methods. Clamp em up and/or throw a bunch of weight on. A couple of screws help keep the two pieces lined up.

3. Sealing the wood - If you are going to seal the wood what is the best product? Epoxy? Fibreglass resin? Brand names? What is the best method? What is the best way to seal the holes where the motor mounts etc?

Fiberglass and poly resin is probably best. Most of us skip the fiberglass and use epoxy resin instead which is great. US Composites and Clarkcraft are the favorites for epoxy around here.

For the holes - overdrill, fill, re drill is the best. Or, you can also just drill and coat your fasteners with 3M 5200. Not as good but still very acceptable.

If you were going to replace a transom on an aluminum boat and wanted to do it right, how would you do it?

Click on the "Starcrafts Being Rebuilt" thread in my signature and you'll see exactly how a whole variety of guys put theirs together. Enjoy!

 

[lakelover]

Re: Replacing a transom on an aluminum boat

Yes, there are menay ways as evidenced on this board!

I can't tell you the best way, but here's how I did mine:

Two pieces of 3/4" exterior ply, glued with Gorilla glue (clamped and screwed with drywall screws). After it cured, and all my holes were drilled, I applied 2 or 3 coats (can't remember which) of epoxy resin that I bought from US Composites, using their 3:1 medium hardener. You can see some photos in the thread in my signature.

After that, I sanded and applied Rustoleum marine primer, then Rustoleum marine topside paint, buiding up several coats, lightly sanding between coats. Pay particular attention to the edges!

Good luck.