15' Aluminum Transom Repair

[Churak]

Hello everyone!

Just started a repair / restoration of an aluminum boat that was my great grand fathers. Completely gutted the thing yesterday and today, rinsed, brushed , and vacuumed out the hull to assess damage and hull viability. Overall I think the hull looks great save some surface corrosion on the inside and some serious stuff on the stern hull / transom. Everything is riveted together and from what I've read so far, I think a repair is well within my capabilities with some learning. The edge of the transom looks to be solid and the rest of the hull that isn't directly beneath the transom tresses looks good so that's what I'm aiming to replace. See attached imgur album for a better look at the problems and my proposed cuts: http://imgur.com/a/tvbY5

The only change I might make is pulling the cut in the hull to before the rib to remove the need to replace that. The rest of the transom will undergo a full rebuild as well, new plywood and support structures ( If the current structures aren't in as good a shape as they seem ). My first goal is to get this boat sea worthy / running again before tackling the rest of the rebuild. This boat will be salt / fresh water, as something to keep in mind. As a side note, if anyone knows of a company that does soda blasting in/around the Northshore of MA, I would love to hear about it!

 

[gm280]

:welcome: Churak to iboats. Always nice to have another boater on board...

I have to admit, that transom area is in serious condition. It absolutely needs to be replaced. And since this is an aluminum boat, that will take some special care to do. If you really are serious about repairing this boat, then we are here to offer suggestions and ideas. But before jumping into this project, look over the entire hull top, sides, bottom and everywhere first to verify there are no other serious issues. Because if there are other areas of such condition, I myself would have to really think about repairing this verses looking for a newer newer boat. But that is just my personal opinion. If you do still want to tackle this project, then you have to meticulously remove that transom at its present attachments places so you can use it as a perfect pattern to make a new one or have one made. JMHO!

 

[Churak]

Thanks for the welcome gm!

Yes, I know the transom is in some detrimental shape. However I work from home at my desk for 11-12 hours a day doing programming and design work. I've needed something like this to get me out of the house and keep me sane so this is less about just getting a boat and more of a stress reliever and having a project of my own. If I have to put time into the repair it's something I'm 100% willing to do. I've done limited metal work before and I'm up for a challenge and some learning!

Overall the rest of the hull looks to be in good shape. The only other concern I have is on the keel. It's a bit beat up, but it doesn't leak and the metal seems nice and strong. You can see the keel in the last two pictures in this new album: http://imgur.com/a/sbzfS
This is a concern for me, but not nearly as much so as the transom. My first goal will be to ensure that the transom can / will be replaced then tackle the keel and verify the possible damage there.

Thanks for giving the me heads up about the nature of the project! I look forward to digging into it and making this boat something I can be proud of!

EDIT: I just wanted to add after re-reading your response. I know I mentioned the keel, but nothing else on the boat is as bad as the transom. That's 100% by far the worst portion of this boat. Overall the two problem spots I see are the transom (super bad) and the keel (minor, seems strong with the scientific screw driver stress test, though I will reserve total judgement till I can get the paint off the keel and see what it looks like).

 

[TruckDrivingFool]

:welcome: to iboats Churak! That's the kinda nightmare that wakes me from a deep sleep.

If you hadn't mention Great Gpa I'd of already told you get your scrap value and sell the trailer to buy a decent fish finder for your next boat and moved on and I would seriously consider this plan.

I say this with all due respect, ask yourself would GGpa be proud to see her float again or cuss you for being on a fools errand?

You don't mention how you plan to replace the cut out metal but I'd try my hardest to stay away from welding in patch panels for fear of cracks.

If it were mine to do I'd forgo the cutting out of anything, remove the first floor rib and knee braces for reuse (provided they aren't ate up), remove the rivets from the keel and strakes up to the to the same point, and plate over the bottom from side seam to side seam on the inside with the same thickness Al that you have in the non ate up spots. The transom - Straighten it out as best as you can and plate over the outside. You can then go back and fill in and fair the corroded spots with JB weld/Marinetex or the likes. There will be some fussing/fitting either on the top or bottom of the knee braces to retain the right hieght for you SW to go back in correctly but that is the best way I see to repair it.

 

[Churak]

I like to think I serve as a grim reminder to what too much aspiration and free time can do to a person's expectations. Honestly he'd probably curse me for taking her apart because she was perfectly good before! :laugh:

My plan was to rivet a new piece of patch aluminum in place of the old stuff. So rivet to the sides of the old transom after the cut. What kind of consequences would I be facing if I just shored up the old metal with new stuff? Wouldn't that potentially lead to corrosion getting stuck between the two sheets and cause further issue down the line? Or would that issue be a non-issue if I clean up the area and let a layer of oxide form before slapping on that repair piece?


I do think I need to grab some paint stripper, a wire brush, and some goggles to reveal what the boat has in store for me on the hull to decide if the transom replacement is all that's necessary.

 

[gm280]

I like to think I serve as a grim reminder to what too much aspiration and free time can do to a person's expectations. Honestly he'd probably curse me for taking her apart because she was perfectly good before! :laugh:

My plan was to rivet a new piece of patch aluminum in place of the old stuff. So rivet to the sides of the old transom after the cut. What kind of consequences would I be facing if I just shored up the old metal with new stuff? Wouldn't that potentially lead to corrosion getting stuck between the two sheets and cause further issue down the line? Or would that issue be a non-issue if I clean up the area and let a layer of oxide form before slapping on that repair piece?


I do think I need to grab some paint stripper, a wire brush, and some goggles to reveal what the boat has in store for me on the hull to decide if the transom replacement is all that's necessary.

I can see a possible laminated transom if you can clean off all the corrosion and treat it with something that will stop any further corrosion. But the transom has to be able to support the engine and the thrust output as well. So more then just a laminated application will be needed too. Can it be done? Of course it can. But only you can make that decision. Safety has to be the number one decisions and then cost needs to be factored in. But anything can be repaired, it is usually the coat that helps make that decision. If you do decide to move forward, post your decision and we will certainly offer help, ideas, and suggestions to achieve the best results. JMHO!

 

[Churak]

I think I'm going to move forward with the laminated transom. I took a wire brush to it today, and while there is a lot of corrosion in the middle areas, the outer edge is in good shape and strong. I removed the knee supports today and the corrosion at the base looks solvable with some digging out and epoxy fill. As far as strengthening the transom goes, I know it's usually 1-1.5" plywood which I can run the full height of the transom. On top of that the knee braces there is also a bolt pattern that will hold a horizontal 2 x 4 to brace the transom even further. I'll start the corrosion removal process and start posting progress pics I guess!

 

[gm280]

I think I'm going to move forward with the laminated transom. I took a wire brush to it today, and while there is a lot of corrosion in the middle areas, the outer edge is in good shape and strong. I removed the knee supports today and the corrosion at the base looks solvable with some digging out and epoxy fill. As far as strengthening the transom goes, I know it's usually 1-1.5" plywood which I can run the full height of the transom. On top of that the knee braces there is also a bolt pattern that will hold a horizontal 2 x 4 to brace the transom even further. I'll start the corrosion removal process and start posting progress pics I guess!

Okay Churak, post your progress. We really do love pictures on these fourms. :thumb: