Bondo for repairs

Okay I may be a little late with this question. My buddy sandblasted my boat for me and I used Bondo for some repairs (minor holes, pitting etc..) Will the bondo hold up? Or should I have used something else?

Thanks,

Clint

Hey Clint,

Bondo usually doesn't play nice with Aluminum boats, as the aluminum tends to flex and bondo won't, which may cause the bondo to simply come loose. I guess the success of it will be dependent on the prep work, amount, and location of where you applied it. I'd have a stick of aluminum epoxy on board if it's just for a few small areas and was used below the waterline just in case.

Darn I was afraid that would be the answer. Shucks.

Thanks for the feed back.

USC All-Metal is the way to go - people over at Iboats seem to be using it with great results. I am looking to buy some to have on hand.

https://www.autobodytoolmart.com/usc-all-metal-premium-aluminum-filled-auto-body-filler-p-14787.aspx

Okay so here is my next ?

The bondo area is basically all over the transom (inside/outside). I used it during all stages of the process (after sand blasting, boat primed, after priming and before top coat).

If this stuff flexs and breaks/cracks etc. My new paint job is basically shot? Correct.

What are my options now that I have used this wrong stuff (darn it)? Can I put a piece of aluminum on both sides of the transom (maybe with marine adhesive and stainless screws)? Or use some marine grade plywood on both sides?

Thanks.

What are your goals with this boat? Do you want it to look as pretty as possible? Are you trying to just fish it? Are the pitts deep and possibly going to break and leak? I would not try and add aluminum inside or out. Unless that is really your only option. Adding wood is only going to give you more wood to rot.
If it were my boat and I had done what you did and then found out what you have found, I would probably look at something like a truck bed liner over the paint. That stuff is pretty tough and would probably hold what you have done in place.

But honestly I would tape off the transom and sandblast it again and get rid of the bondo. I would lay some fiberglass over it and once it is set up I would rivit it to the aluminum and then spray it.

( I actually did this on my boat)

Huntinfool. Thanks for the response. Functional fishing boat. The transom had some minor holes through out for years that I just left alone. When I took the motor off and sandblasted the area the holes were more noticeable, so I figured (not bright looking back) to use bondo and apply over it to conceal the holes before priming and painting.

Yikes fiberglass scares me even more than bondo.

I don't think my buddy will give me a do over for the transom. He gave me a good deal as it is.

Hey Clint,

Could be that you don't have a problem with it, and if you do it might be years. Then again it might be in weeks. Lots of factors I suspect will contribute. The way I look at is, you've fixed the problem (for now). Time to get that thing on the water and use it, knowing that if it ever does become a problem, you'll no how to fix it right the next time. In the meantime, like I said, carry a stick of aluminum epoxy, and make sure you have a bilge pump on the boat.

I'll keep my fingers crossed your ya and hope that it stays put for good! If you ever decide to do a redo on it, it won't have to be sandblasted. An angle griner or drill with wire brush attachment will take it all off.

Thank you guys for all the advice. I will try to post some pictures of before and after.

Before shot of transom
https://i723.photobucket.com/albums/ww234/ClintP_photo/DSC01143.jpg

After shot of transom with bondo applied
https://i723.photobucket.com/albums/ww234/ClintP_photo/IMG_1589.jpg


Aft shot of bondo fix.
https://i723.photobucket.com/albums/ww234/ClintP_photo/IMG_1588.jpg

I have another thread in the Jon boat conversion about a deck. I will post some before and after picks. Could you please assist with my layout?

Thanks,

Clint

I'll be honest. It doesn't look all that good anyway. No offense. Bondo is like an art. I don't think you would need that on your transom. I would like to think you could get most of that off with a sharp putty knife. Then, you could use the wire brush on the remains. Replace the wood with conditioned plywood*, and prime, and paint again.

*Conditioned plywood.*
Those that are non pressure treated, and water-resistant, by other means.

I used a wire brush attachment on an angle grinder for my boat and it works wonders. No sandblasting necessary if you're only redoing the transom.