Do I need bottom paint.

[gazelle]

I will be painting an aluminum 22ft cuddy, the boat will reside in a freshwater lake and will be in a slip for 6-7 months. Do I need to paint with an official antifouling bottom paint?

From what I can tell the antifouling bottom paint helps prevent corrosion in salt water and also makes it easier or even prevents growth on the bottom. I am not really worried about growth, I can wipe down every once in a while with a wet rag while swimming.

So can I use the same paint that I would for above the water line? It is cheaper, it will allow me to paint the boat all at once, and comes in multiple colors. I read everyone saying to use a bottom paint but am not sure why. Will the other paint flake off if it sits in the water?

Second question

When stripping the aluminum I noticed some of the seams on the boat between two different pieces of aluminum had a red colored rubbery caulk. I assume this was used to help keep out leaks. What should I use to replace it with? Should I use gluvit or a 3m product?

Thanks a ton, you guys are great!

Gazelle

 

[tommays]

Re: Do I need bottom paint.

What do they do in your area ?

That would be the best bet


Tommays

 

[gazelle]

Re: Do I need bottom paint.

tommays, my lake is relatively small so there are not many aluminum boats on it that are kept in a slip. Most of the boats are fiberglass or trailered.

 

[reelfishin]

Re: Do I need bottom paint.

I lived on a freshwater lake in PA for a while and bottom paint was rarely seen there, but most people there had boat lifts and the water was fairly cold. I had a smaller aluminum boat there and never had any problems with either corrosion or fouling, and that was a bare aluminum hull, and it had most likely been in that lake for around 30 or more years. (It came with the place).
Usually bottom paint is used simply to prevent barnacle attachment. You have to be careful about using some bottom paints on aluminum, those that contain copper can actually promote corrosion, it actually promotes electrolosys. I am dealing with an aluminum hull now that was coated and used in saltwater, the only pitting is where the bottom coating was.

If your hull needs painting, I would simply clean, sand, and strip as needed, reseal any seams with an appropriate sealer, then prime any bare metal with a self etching primer and then paint with a good marine grade finish paint.
If you have rivets that are leaking, either tighten those or replace them. Make sure what ever you caulk with is paintable and rated for aluminum. You may have to prime the hull before recaulking.
The hull I have here will end up with an epoxy based paint after I repair and fill all the pitting. I'll use Gluvit on the inside, but the outside will get filled and sealed with an aluminum filler epoxy, primed and painted.