What do I need to do to paint a fiberglass boat

[Jeremiahjohnson365]

Hi I’m looking into painting the bottom of my fiberglass boat and would like some advice. What do I need to do for prep and what paint would you recommend?

 

[docmirror]

Well, this is a pretty big subject. First off, you have a FG boat with a gel coat finish(pretty sure). Gel coat is NOT waterproof. It actually absorbs a small amount of water, and that keeps it from cracking. Which means, if you use a latex paint, you'll be ok. If you want to use an epoxy base paint, you'll need to completely dry, and completely seal the gel coat with the new epoxy paint.

Presuming you don't want to seal it, the project isn't too hard. Scuff everywhere you are going to paint with 400 grit. Choose a primer and top coat of latex paint, and put two light coats of primer on, with a dry sand in between. One more dry sand, then a wet sand, let dry fully and two coats of the color top coat.

For an epoxy or other non-latex finish, the hull must be dried, and the same steps applied, but there can be no voids. I would do at least 3 primer coats, and two top coats of the epoxy. It still might blister, depending on your skill with the drying and painting.

 

[jbcurt00]

Why are you planning on painting the hull?

 

[tpenfield]

Well, it depends on the reason for painting the hull bottom.

If it is for anti-fouling (preventing marine growth), you will want a barrier coat (Interlux Interprotect 2000) and then an anti-fouling paint of your choice (make good choices).

If it is not for anti-fouling, perhaps just the barrier coat.

 

[Scott Danforth]

Hi I’m looking into painting the bottom of my fiberglass boat and would like some advice. What do I need to do for prep and what paint would you recommend?

Scuff everywhere you are going to paint with 400 grit. Choose a primer and top coat of latex paint, and put two light coats of primer on, with a

first, latex paint should not be anywhere near a boat. it will come off in prolonged exposure water

second, assuming you have a project boat and you want to use paint vs gel.... See link 19 of the stickies in the restoration forum. https://forums.iboats.com/threads/how-tos-and-other-great-information.283508/ This is only for boats that live on a trailer and get day-dunked. this is not for any boat that sees any more than a days use in the water.

I personally found that re-spraying gel is the best for me. so I went with gel

now, assuming you have a boat you want to bottom paint
sand the bottom with 80 grit to give the gel bite
2 coats of barrier coat
4 coats of bottom paint

 

[docmirror]

I have at least 11 painted boats over gel coat in my past. I ran a refurb shop in Needles CA, and would repaint Schuster, Kona, and other jet boats regularly. It's also easy to touch up when they go over sand bars. Using the steps exactly as written, latex will last many years. Believe it or not, I use latex swimming pool primer, and pool top coat paint. It's designed and formulated with anti-algae growth formula, and will provide good service on most any kind of trailer boat.

Painting the bottom of a slip kept boat is not suitable. That would be done with regular anti-fouling 'bottom paint'. If painting with gel coat, might as well use a bucket and broom, cuz that's what it's going to look like when finished.

 

[tank1949]

Hi I’m looking into painting the bottom of my fiberglass boat and would like some advice. What do I need to do for prep and what paint would you recommend?

For above the water line, I have always used automotive urethane paints (2 parts) and a lot of sanding. No primer was needed.