Paint/Coating for leaky aluminum dinghy?

[sealover]

Full disclosure: It's not really a dinghy. I'm technically a power boater... I have a 1950's (?) 14' aluminum row boat that I clamp a 4 HP outboard onto and go crabbing. Except it leaks like a wicker basket. I caulked every last rivet and seam from the outside and and it still takes on water. I'd like to paint/coat it with something (inside or out, or both) that will reduce the amount of water coming in.

ideally whatever this miracle product is, it will:

1. cost well less than the $100 the boat is worth
2. be of a light color if it's going inside of the boat so it doesn't cook me and the crabs on a sunny July day. (otherwise I'd use that black screen-door-in-a-boat stuff on TV?)
3. not require scuff sanding around all the obstructions inside or removing the globs of silicone caulk on the outside.
4. hold up to being beached on rocky/sandy shores, being scratched by metal crab traps, and survive on a boat that is stored upside down on it's trailer under a walnut tree when not in use.

Yes I'm asking for a lot. But I'll concede: I'll touch it up every year if whatever it is will survive in a can in my garage for multiple years, and I will pressure wash the heck out of the boat and let it dry for weeks indoors before applying. And I really don't care what it looks like.

I've looked on various other forums and have received all sorts of suggestions that don't meet any of the above (Why yes, I'd love to have it Rhino-Lined but that will cost more than the boat, trailer, motor AND the car I pull it with...) so I thought I'd take it to my sailing bretheren here. We seem to be a more realistic, thrifty bunch.

Remember, this is a $100 aluminum row boat that was made when there were only 48 states. It's really not worth much time or effort. I just want to get a few more years out of it.

Thanks!

[CaptainForce]

I think I have your answer. Empty one entire caulking tube of the white 3M 5200 into a paint can an thin it to a brushable, yet still fairly thick "paint" with acetone. Adherence should be good if you have wiped off the surface with the acetone first. Take care and joy, Aythya crew

[sealover]

Seriously? That sounds easy enough. Never thought of making my own product. Maybe I'll do that on the inside and house paint on the outside (that's made to go on aluminum trim/siding, right?)

[celenoglu]

Aluminum is difficult to coat. It needs a special primer for painting.

[Faster]

When we painted our mast years back we were advised to wash it down with vinegar before painting (a mild acid wash).. we did and the paint still looked fine 10 years on.

FWIW any sealant/coating will probably work better on the outside, as long as whatever you use won't get worn off by passing water. A membrane preventing water from getting into the rivet cavity will be better than an inner membrane dealing with water that's already made it through that gap.

[tommays]

Use Gluvit on aluminum fishing boats to repair leaky aluminum seams and rivets.

Gluvit seems to have had success

[ewoden]

Soda or shell blast the interior, mild acetic acid wash to etch, haul over to local truck bedliner place for a spray of Rhino or buy a gallon of Duron Herculiner roller and a detail brush.

[jrd22]

Go to Home Depot, Lowes, etc and get a gallon or five of the goop used on aluminum roofs, RV's, etc. Slop it on the outside of the boat, reapply as necessary. I would try to get as much of the silicone caulk off the seams first and wipe down with acetone and stainless steel wool, almost impossible to get anything to stick after you've contaminated it with silicone.

[sealover]

Follow up- someone else suggested a big caulk tube of 5200, but said "heat it first, it'll thin out and last longer. He slides the tube up the tailpipe of his running pickup truck. How's that for ingenious!

[deniseO30]

Did you ever think of having a friend help you block and hammer the rivets?