Transom work on a riveted tin boat

[Bows Up]

Is it possible to weld to a riveted boat ? Transom cap on my 18' Lund has been cracked by previous owners over tightening transom bolts on motors and I am wondering about the integrity of the plywood in the transom. Love the boat. Good power and kills fish so I'd like to hang on to it.

Garage stored but I'm thinking if I don't get after this I'll be screwed down the road by water intrusion. The net has lots of examples of people carving out the old plywood but zip about the possibility of welding.

Thoughts, anyone ?

 

[NautiGirl]

The welders on here would give you the expert opinion. My research says welding the thin aluminum is a very delicate task to only be considered by the very experienced aluminum welder with the right equipment if at all. I've seen bad attempts ruin the area. For the transom, if the wood is not rotten, put some 3m5200 over the crack, then get some bendable alum plate bent as a new transom cap to fit over the old one transom as a protective cover and remount your motor.

 

[Dave S]

If wood is dry and solid, I'd just get one of those plastic transom saver plates or some thick aluminum like nauti mentioned, and create gasket with 5200.

 

[FishWhisperer]

Sounds cosmetic to me but regardless, you can't weld it. You would have to grind whatever aluminum that is there down to paper thin to get the impurities, salt, etc off. Also, the existing aluminum has no doubt been subject to a certain amount of electrolysis. Prob can't weld to it anyway. And, you'd start your transom on fire under where you're trying to weld if you're doing it in situ.
As Nauti and Dave stated, pull the existing cap off and throw it away. Check the integrity of the wood under it, if it's structurally sound, seal it up and cap it with a shiny new piece of aluminum.

 

[Sculpin]

It is weldable but as fishwhisperer pointed out not worth it to do what you want. I remember reading a comment from Lund boats once and it was something along the lines of "we will start welding our boats when they start welding airplanes". The riveted tin boats are designed to flex a certain way and if you weld on them you are creating stiff points and can apparently cause issues by doing so.

 

[cullenskink]

GLUVIT

http://www.marinetex.com/gluvit.html

I used on a leaky riveted boat, made the thing tight asa drum. Industrial plastics and paints has it.

 

[Bows Up]

Nasty job ahead, perhaps. Doubt that it is dry under the cap as there is corrosion. Oh well, have to finish the house and deal with a daughter's wedding before that project gets to the top of the list.

I can clearly forget any option that involves welding. Thanks gentlemen.