I recently bought a used aluminum boat and it looks pretty rough. I was just wondering how would i go about painting it? The previous owner also put some silicon around some areas and i was wondering how would i smooth them out so that it looks good. I was also wondering if i could just scrape all the silicone off and just get those areas welded? What do you think?
Welding would indeed be the preferred repair. After welding, it can be ground smooth and sanded for painting. After fixing all the bad spots, leaks, rough edges etc, use a paint that is made for aluminum and water, maybe a marine paint. And if you want it to look really good and last a long time, use a suitable primer before painting. If you need to do it as cheap as possible, you can scrape out the old silicone and repalced it with some waterproof epoxy that bonds good to aluminum. Then just sand it down by hand, and paint it with the cheapest aluminum paint you can find. Use a rough tectured anti skid paint on the floor, so you wont slip and fall when its wet.
If the aluminum skin is cracked, then silicone caulking is NOT the proper way to repair the cracks. Yes, by all means, remove the silicone and have the hull welded if at all possible. Just make sure that the person you hire to do the welding is experienced in welding aluminum sheet. It takes a very delicate touch.
it would be useful to know if the silicone patch was on a rivet line or split sheet, but either way it should be removed. if its on rivets they need replacing, if its split sheet it should be welded. bed liner can be applied and if it is the slick type can even eliminate the need for rivet repair or slight cracks in sheet applied to the hull (basically making an aluminum reinforced plastic boat), though it will add alot of weight to the boat! textured bed liner would make a fine floor coating, but no matter what is going to be heavy. also you must sand everything down and precoat with a good aluminum primer whether you use the bed liner or proper paint! otherwise it wil seperate and peel off. And for the love of god do NOT use any antifouling paint with copper directly on the aluminum or try to make your own rivets with steel or stainless bolts! It will eat the boat (electrolysis)
Get a TIG welder and do it correctly. Aluminum vessels use Aluminum Rivets or are Welded properly. Just be very very careful, Aluminum is very very toxic material when heated. The dust from sanding/scraping it can cause all sorts of problems. If it were my boat and was failing that bad, I would scrap it and use the monies, plus some savings to get a decent vessel in good condition and USCG approved. I think you are talking about Rhino Liner, may as well use that goofy Flex Seal junk, will last a season, then will fail, miserably. Any paint on any surface requires proper preparation, time and knowledge. If the vessel is 14', you will have more $ in repairs and supplies than the thing is worth. And then it would be a repaired vessel that might not be stable enough to do hull speed. If you are planning on using an OB motor on it, the transom, that is the back should be carefully examined for weaknesses and defects. If any scraping is to be done, let the person that is doing the welding do that. Always get an estimate. That is what I know. The bed liner is a bad idea, yeah it kinda works for Decks, but is designed to be applied with Primer and Base onto Steel or Sheet Metal. Not many Truck Beds are Aluminum. There are Marine outlets that sell the correct chemicals for that, just be careful.
