Aluminum Boat - paint prep process

[QC]

I am still planning my assault on a little 14' Sea Nymph I am going to paint. I have posted similar, but getting down to the nitty gritty . . .

1) I was planning to simply wash the entire boat with 50% vinegar and water and then go with primer and then Rust-oleum both from cans. Should I wire wheel this entire thing first? I'd love to skip that step, but I'll do it if necessary. I am guessing the wheel would remove the little oxidation burrs all over the hull. Orbital sander?

2) I am going to use Gluvit on the bottom as apparently it is designed for bottoms and I figure I only get one shot per quart. I'd really like to avoid another $40, but I can't figure out how to let the bottom cure and flip it over before this quart sets to do the inside as well. Any bright ideas? Bottom good enough? If you only get one shot, bottom or inside?

 

[CalicoKid]

Re: Aluminum Boat - paint prep process

Uuuh, why not coat the inside first flip it and do the bottom second?? Could set it on wide sawhorses on its gunwales?

 

[QC]

Re: Aluminum Boat - paint prep process

I guess I assumed you wanted/needed gravity to help it work into any leaks . . . If I can do it on its side then done deal.

 

[swimmin' for shore]

Re: Aluminum Boat - paint prep process

I'm not sure if you gave enough information, OC. I've done a handful of little aluminum boats, and the first question is how much old paint or oxidation is on there now? If you just have some oxidation, I'd just clean the heck out of it, prime and paint. You didn't really say how nice you want it to look, either. If you're looking for a showroom restoration, you're going to put in a lot of prep work. All old paint has to come off or be faired in. If you want functional and longlasting, I'd get an epoxy paint. If you want it to stick well to the aluminum, you're going to need a self-etching primer. That does a really nice job of sealing little seams and such, as well, although it's not a leak stopper. I like 3M 5200 as a backup for my seams. I always use it when I rivet, as well. Gluvit will work very well as a sealer, too. Rustoleum and other enamels have never held up well for me, so I've learned to just use epoxy paints now. They cost a bit more, but well worth the cost. Check out www.topsecretcoatings.com. Read some of the blurbs on their marine paints and see what you think.

 

[CalicoKid]

Re: Aluminum Boat - paint prep process

Gotcha QC

 

[QC]

Re: Aluminum Boat - paint prep process

Sorry sfs, fisrt it doesn't need to be perfect. I plan to sell the boat, but am giving my 13 YO a lesson in "don't need new" and some tiller use.

The oxidation is not real bad and there is almost no paint, but this is my first aluminum boat. All fibergalss before this one. It looks like the inside was painted once, but long ago and it is basically gone, there is no need to remove anything but the reg numbers, lake permit stickers and the old Sea Nymph logo stickers.

There are others here that I thought swore you could simply use the vinegar wash as the etch phase and go with primer and rust-oleum. I was headed that way until I started considering the Gluvit use. It only barely leaks as is. I would say a seep as I can't find it, it doesn't get worse after the first little bit shows up in the stern, and it seems to hold water if I fill the hull with water on the trailer. . .

 

[Bob_VT]

Re: Aluminum Boat - paint prep process

Do the seams, joints, and rivits with the gluvit. A good deal of the leaks are probably related to where there is a support brace. Examine the seams under the seats .... that is a spot often neglected. One quart size can will be more than enough to do the bottom. The gluvit takes a good 24 hours to dry.

DO NOT wire brush.... it can cause future problems. an orbital sander is a better bet. Paint remover works great too.

The vinigar wash followed by touch up spray paint (Zinc-chromate) on the bare aluminum spots followed by your paint.

Did you do the transom? Were the bolts coated with 5200 or grease? I would have done that as a precaution to prevent galvonic action.

 

[QC]

Re: Aluminum Boat - paint prep process

Thanks Bob. It is basically all bare aluminum as is and does not really need to be sanded at all if I can get away with it. There is evidence that the bottom half of the inside of the hull was painted green (see Pic), but it is little more than a stain now, no left over paint stuff. I am only concerned about prep for painting and whether the Gluvit would be best applied on the bottom or inside of the hull. If I can apply it on its side and do both, then great. Again, I figured that gravity would be an issue (possibly good) and figured I would only get one working session. i.e. either flipped over and use it on the bottom, or left upright and applied on the inside, but maybe Calico's plan above. This hull is so light I can flip it any way I want to alone.

As far as the transom is concerned I totally removed the existing OB pad and I have made a new one. The reattaching hardware choice is now up to me. I planned to use new stainless hardware for that. I can coat the bolts prior to re-installation. Thanks for that tip. I would've missed it. BTW, there is no electrical whatsoever with this boat. I don't plan to add a trolling motor or battery. Plan is cheap and sell as long as I am being fair to the new owner and giving my kid some good experience. I have a new 5hp POS Briggs & Stratton to mount. It planes it and runs around 12 MPH with two aboard. I got three of them on Craig's list for 600, sold two on ebay for 495 ea., 280 for the hull and trailer. I am basically up 100 as it sits now 8) and would like to keep it that way . . .

 

[swimmin' for shore]

Re: Aluminum Boat - paint prep process

Bob's absolutely right about the galvanic corrosion. I'd just put some 5200 everywhere I was going to put a bolt through the aluminum. Stainless bolts are your best choice.
I didn't say that you couldn't paint with Rustoleum, or that you shouldn't. If I was looking at a boat, though, I'd rather buy it as is then with rustoleum on it. My personal experience has been that it just doesn't dry hard enough to take any kind of beating. If you have a paint sprayer at home, I'd buy a decent epoxy paint, thin it, and paint. If you're putting it on by hand...Well, I refuse to paint by hand anymore, so I'll let someone else chime in on that. Have you considered leaving it bare, though? A lot of people never paint aluminum boats, and it might be just as easy to sell that way. It's not a saltwater boat, so paint is more of a cosmetic thing than a protective coating, in this case. Just a thought, anyway.

 

[Bob_VT]

Re: Aluminum Boat - paint prep process

Do not use the gluvit on the outside. I would concentrate on the seams on one side and do the other side the next day. Gravity is your helper with gluvit and it flows downhill.

 

[QC]

Re: Aluminum Boat - paint prep process

Thanks to both of you. That is now two votes against rust-oleum on the hull and two votes for epoxy based. I think I've got it now . . .