I just purchased a used 14' aluminum boat with a 15hp Yamaha, Minn Kota All Terrain TM, Lowrance X47, and a trailer.  The boat just needs some minor TLC in some areas.  The back of the boat has a bunch of white stuff on it (I forge tthe boating term) and at certain spots around the tie down hooks it seems to have eaten a bit of the metal away.  There is some JB Weld in some of the holes but there is 2 screws below my water line where it looks like it is pitting as well.  Honestly I don't want to dump a ton of money into the boat because what I paid for is really the motors and that's it.  What would be best to seal these problem areas up?  My goal is to seal them and find the best spraypaint (yes spray paint) primer and top coat to cover it.  Let me know if you have any "Marine Bondo" type recommendations as well as an ok spray pint brand that will somewhat adhere to aluminum with some prep.

Thanks!!!

Corrosion on aluminum can be a bad thing but stopping it is easy

Step 1

A good scuff sanding; don't remove to much metal, unless it's over half the thickness of the metal I wouldn't worry too much about it.

Step 2

Apply Alodine 1201 without dilution by brushing or swabbing with sponge. Rinse with water and surface is ready for paint. This is a visible coating which leaves the surface with a golden coloration. The alodized surface provides protection against weather and firmly bonds paint. 1 quart treats about 100 sq. ft.

Step3

Epoxy putty, Ready-to-use metal repair putty, dent filler and patching compound. A good one is Alvin Products Lab-metal

Step 4

Painting it is also easy Kraylon spray paint

ALUMIPREP #33 or METAL PREP #79 before the ALODINE #1201 application???

Neither scuff sand, clean toughly with water, dry and apply alodine

Catt thank you very much for all your help!!!  What grit is good to scuff sand?  Also if it makes any difference the boat is painted but chipping (attached picture)  When I take a rag over the paint if i spray it with a cleaner my towel tunrs the color of the paint so you can tell it's old paint.  Let me know.  I ordered everything you recommended so far.

Here is the boat

I would cut that part, not to much just enough so theres no rust. If you have or know someone who can weld, that'd be perfect. But jb weld is just as good. If you do, cut it, prep it, and put the jb weld on there. Jb weld is probably, if not harder than the metal itself. I know for a fact from experience its really good.

Thanks Bow.  If I were to use the jbweld would it stop the corroision you think? Along with filling in the holes?

Scuff sanding then applying alodine will stop the corrosion; do not cut the corroded section out unless the pits are over 50% of the depth of the original metal thickness.

Use at least 180 grit sand paper to remove the corrosion followed with 220 grit sand paper. Fill in the pits with Epoxy putty, sand, and paint

I am backing up Catts suggestions and will add that a quick shot with a fine grain from a sandblaster gets all the pitted parts nice and clean before hitting it with the Alodine.

You are just looking to remove the existing cancer, THAT"S IT!!  As soon as you have new metal showing, clean it and begin Catt's suggested process.  Just my .02, good luck with her!

It looks like a great platform to perform some mods on...keep us posted w/ pictures of it.

Wayne