my corroded transom, and restore. advice needed! PICS!!

this is what i found under the wood on my 1963 starcraft. all the bolts had been replaced with regular steel bolts, and two drains for the bilge pump were made from copper :? :shock: :evil: sooo, as you can see, the entire transom has corrosion and pitting, but around the bolt holes is are the worse places. the corners have very little to no pitting. the thickness of the transom was 1.5" with the original wood, 2 sheets of .75" ply on the inside.
should i put one piece on the inside, and one piece on the outside, sandwiching what little aluminum is left, or put both pieces inside, and use large washers on the heads on the outside?
or should i scrap it? thanks, mike,
starboard

port

as soon as the sun goes down i bit and there is no glare, ill take some pics of the corners.

i would put 1 piece on the ooutside and 1 on the inside

here is each corner and the entire stern

bassboy can probably give better advice...

but, I would find me some aluminum to put on the inside (cut to fit the transom down to just below the lowest holes).. I would use some 3m 5200 sealant to attach the new piece of aluminum to the transom (especially around the holes). Then I would attache another 2 pieces of .75" ply like what you took off. I would use deck paint on both pieces of wood (all sides and edges)... I would use ss bolts to attach the wood through the outside of the transom, dabbing each hole and bolt with the 3m 5200.

I'm just thinking how I would do it, so it may work for you, but I'm sure you'll get some more ideas.

russ010 said:

bassboy can probably give better advice...

Click to expand...

I was going to pretend I missed this thread....

Anyway, most of my boat dealings have been with freshwater boats, so I haven't been around much corrosion like that, and while I do know what to do to prevent corrosion, as in what alloys of bolt, and aluminum to use, especially in saltwater applications, I am not sure exactly the best way to repair it.

I am going to see if anybody else on here has a better idea than I, and if nobody does, I have a couple places to send you, that will know the answer.

ive said it once and ill say it again street signs lmao

What Russ said is a good idea. Other than that, do you know anyone that can work with and weld aluminum? An entire new transom might be the answer if the metal of the sides (where they meet the transom) aren't too thin/corroded to accept good welds.

Waterwings said:

What Russ said is a good idea. Other than that, do you know anyone that can work with and weld aluminum? An entire new transom might be the answer if the metal of the sides (where they meet the transom) aren't too thin/corroded to accept good welds.

Click to expand...

And use stainless steel hardware sealed with 3M 5200 marine sealant.

Sooooooo, how did this turn-out? I'm currently working with a very similar condition on a Grumman 1446 Jon and am trying to avoid replacing the aluminum on the transom. Today I scrubbed off all the corrosion with Barkeeper's Friend and Scotch-Brite, then CLR and then another scrubbing with white vinegar. The metal is now nice and shiny. Was thinking of filling the holes with Marine-Tex. The wood on the inside of the transom is being replaced with two layers of 3/4 ply bonded with PL and coated with epoxy. I am going to add a single layer of epoxy coated 3/4 ply to the outside installed with 3M 3200 and then bolt it all together with aluminum bolts and put a good coat of steelflex on the transom before and after all parts are installed.

I didn't see this one. I do boat repair for a living and I have several ideas in mind, but they all depend on your level of skill and what tools you have available to you.

Putting wood on the outside of a hull in usually a BAD idea. There is no need for wood on the outside of a hull. The transom gets it's strength from the wood on the inside. If the wood on the inside is not strong then it will fail. Wood on the outside just transfers the stress to the bottom edge of the wood and allows the transom to bend there.

Putting a new piece of aluminum on the inside of the hull with 5200 is one way to strengthen and seal the transom up. If I did not have access to a welder this is how I would do it. My transom was corroded and I did not want to pay for the aluminum to have it welded, so I just cleaned the aluminum real good, sanded it with 80gr. and fiberglassed the transom and all around all of the corroded holes. I went past them about 6-10". This reinforced the transom, and sealed everything up in one shot. I then built and replaced my transom.

If I had the time and money I would have rather put a piece of aluminum inside, I was just being cheap, and since I work with fiberglass for a living I had it on hand and it only took about an hour to do the job.

Cut two pieces of 3/4" plywood and bond them together. (I prefer fiberglass) Then I prefer to round the corners and fiberglass the transom. Install the new transom and use 5200 to seal the screws/bolts.

I would highly recommend pouring a new solid glass transom. (I am doing one right now for a customer and he has a bunch of corrosion in his aluminum) The solid glass transom is a lifetime transom and you only have to worry about sealing it to keep the water from leaking.

I have probably just confused you more, but good luck and if you need some suggestions send me a PM.