MarineTex. I built a whole skeg out of it once. Held up as good as the original..

Countersink both sides of the holes before filling them. The countersink will keep the filler from possibly falling out.

Bondo will not work. It would be a temporary fix at best. Have some one weld them up it is not going to be expensive at all and will be permanent.

Jon

Been there done just that! JB Weld worked just as good as new. That was 3 years ago.

I went to get some JB Weld and I saw another product. PC-Metal by PCProcucts http://www.pcepoxy.com It is a putty type epoxy. I just kneeded it up and plugged the holes. It hardens in like 5 minutes. You can sand after 30 min. (The JB weld takes up to 15 Hours to set up!) The PC Metal is also waterproof or so it says. I sanded it down and it looks great! Now to prime an paint.

I used marine Tex on my nose cones. worked better than any thing else

When welding is to be done on an outdrive , it must be heliarc (TIG) welded. Aluminum can be easily welded with aluminum mig wire and pure argon, But the weld will be too soft and will not stand up to electrolysis and corrosion in a marine environment.Aluminum also can be gas welded but is a poor choice do to excess heat/ distortion. My 2 cents,
Big Block Billy

ttt

Bondo used under water does not hold up. Over the course of a season it absorbes water and becomes less hard. It is a little hard to describe but I have used it for I/O repair and would not do it again. Try one of the other epoxy fillers.

Doug

Ive used both epoxy and bondo. Epoxy doesnt shrink and I think it works better. Niether have come off. Greg