Please help me fix my transom - advice needed!

[Matt B]

Item 1: I’ve got an early 90s riveted aluminum smokercraft that a previous owner drilled into the transom, and screwed and glued on some wood blocks. (Maybe for sonar? And also for wheels I think) some of that hardware is corroding, and I don’t have the wheels, so I want to just get rid of all that stuff. How do I fix the holes in the transom that will be left?

Exterior views:





Item 2: I want to replace all the wood that the motor mounts onto, as well. There’s the plywood part on the outside of the transom, and also a board on the inside that the motor mount clamps screw down onto. For the plywood can I assume I will want to get marine plywood of the same thickness? Do I have to buy a whole sheet? And for the board on the inside, what should I use?

Also, hardware—I’m guessing I’ll want grade 8 stainless? Where can I find what I need?

Inside views:





Thanks for looking!

 

[Scudley Do Right]

You can remove the hardware and pop in a stainless rivet covered in 5200. Another route would be getting a new short bolt, fenders and lock nut and cover them in 5200. For the transom you can get small scrap pieces of starboard or UHMV from some commercial suppliers for little to no cost. My buddy got me a piece of something stiffer and lighter than those two for my boat but I don't remember the name.

 

[Salmo_g]

I'm not familiar with stainless rivets, but that sounds like a good idea. My boat has transom holes that didn't match the new outboard, so the dealer filled those holes with stainless nuts, bolt, and washers smothered with through-hull caulking compound. They've been on there for 10 years now, and look the same as when first installed. I like the idea of using UHMV instead of plywood. You can get the pieces at Taps in downtown Seattle.

 

[Matt B]

Apparently the previous owner didn’t bother to source all stainless hardware, as indicated by the heavy corrosion of some pieces. I appreciate the tips.

 

[SurfnFish]

Helped a friend with a similar project. We used UHMV for the transom, plugged smaller holes with rivets, cut slightly oversized ovals from sheet metal, coated them with JB Weld, and bonded them over the bigger holes.

 

[Matt B]

Helped a friend with a similar project. We used UHMV for the transom, plugged smaller holes with rivets, cut slightly oversized ovals from sheet metal, coated them with JB Weld, and bonded them over the bigger holes.

The oval patches—inside, outside, or both?

 

[SurfnFish]

The oval patches—inside, outside, or both?

installed on the inside with enough JB Weld to completely fill the hole, sanded flush with the hull once dry. Repairs finished off with two coats of Tuff Stuff epoxy primer to fill any rivet gaps (boat had mild leaks), followed by a finish coat of Rustoleum. Looked great when done, bone dry once back in the water.

 

[Squatchin]

Obviously

 

[Matt B]

Gee whiz, that took me longer to complete than I anticipated. Life!

 

[Eastside]

View attachment 67545View attachment 67546
Gee whiz, that took me longer to complete than I anticipated. Life!

Very nice job! It always take longer for me….

 

[Matt B]

Very nice job! It always take longer for me….

Thank you. A few of the bolts are longer than I would’ve liked, due to selection at HD and not wanting to drive around and likely encounter the same choices anyway, and just wanting to get the job done. So I might hack some of them off shorter.

Also, realizing the majority of that $20 bottle of 3M 5200 is going to set up, I wish I had more stuff that needs gluing up!

 

[SurfnFish]

looks great, Matt, well done. Would definitely reccomend zipping those bolts flush.
5200 can be kept indefinitely if placed in a ziplock bag and stored in the freezer, even if it's just overnight, have had tubes last over a year treated such.