Have some damage to the hull where the motor attaches. Going to weld a 1/4" aluminum plate to red till the holes for the motor. Do I need to cut out the damaged part? Do I need to do anything to keep this from happening again? Any tips?
I think the first thing you need to do is find out what is causing it. Anodes are probably history on your motor. If it were mine I'd cut out the affected area, patch it and then put a plate over it. All the work you do won't be worth spit if you don't find out the cause though.
Ding ding ding! We have a winner! Treated wood eats aluminum. I've seen some dandys that were left on treated bunk boards. I'm not 100% sure, but I think that actual marine treated wood is ok. Might want to Yougoogle it.