What is the best way to clean and store an electric blanket?
I am not sure that you can get marine grade aluminum rivetsIf not, monel metal will probably be your best option.
I would just use standard pop rivets and seal them with a paintable filler, or you could seal the backside of the rivet if you have accessThose crush rivets mentioned above are a pita if you have alot to rivet together, but you can get them more flush (we used them a lot when i worked in aviation)
Go to ol paws boat motor websiteThere is a forum that talks about repair and maintaining aluminum boats.