Bottom Paint for a trailered boat

BTL

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I bought a 1989 Wellcraft 18 Sport last August, and it has old, nasty bottom paint that is a total eyesore.



The paint is a powdery blue ablative that comes off with any contact, it reminds me of pool cue chalk.

I realize I don't need bottom paint since this boat stays on a trailer, but if I want to put on a new coat of paint purely for cosmetic reasons, do I need to do any sanding or priming first, or can I just paint directly over this stuff?
 

jbcurt00

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Old has to come off

wear all the proper PPE you dont want to breathe the bottom paint or gelcoat dust
 

alldodge

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Just had my boat bottom paint removed (by searay dealer) and I painted it. Agree, old paint must come off and 80 grit is best. I used Interlux VC Performance epoxy. The VC will bond to fiberglass or Gel coat, but will not bond to other paint.

Could also paint it with other types of paint, but old paint use come off, otherwise it will flake off later and need to be repainted again
 

Ned L

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If it is an old ablative I might suggest trying a scotch brite pad and water. That may take most of it off with no dust.
 

Woodonglass

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Is it the original Gel Coat or Actual Ablative "Bottom Paint" or just old UV damaged GelCoat.? Was the boat originally stored in a Marina?
 

BTL

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Is it the original Gel Coat or Actual Ablative "Bottom Paint" or just old UV damaged GelCoat.? Was the boat originally stored in a Marina?

It's definitely paint, the original bottom color is red, which I assume was gelcoat. It spent most of it's life on a trailer but the previous owner kept it in a wet slip for a couple season which is why it got painted.
 

Scott Danforth

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get mask, preferably pressurized, fire up large 5hp air compressor and a roll of 80 grid disc for the DA........spend 8 hours sanding thru the paint. then re-paint with something like Pettit Vivid white or anything else.
 

BTL

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get mask, preferably pressurized, fire up large 5hp air compressor and a roll of 80 grid disc for the DA........spend 8 hours sanding thru the paint. then re-paint with something like Pettit Vivid white or anything else.

Ugh, that is not my idea of a good time. I'll give a few scrubs with the scotch brite pad like suggested just to gauge what I'm dealing with, and if that isn't doing anything, maybe I'll just bite the bullet and pay someone to remove it.
 

Scott Danforth

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there are companies that dry ice blast. its about $50 a foot of hull length.
 

dingbat

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I would recommend Fiberglass Bottomkote ACT on a trailer boat.

No need to completely strip the bottom. Remove any loose material and paint over what is left.

Holds up well to the wear and tear of trailer use. Painted twice in the 6 years I owned the boat
 

Scott Danforth

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the only colors for the Interlux Bottomkote ACT is Black and Blue...... on a white hull, it stands out like a sore thumb.

that is why I recommend something like the Pettit Vivid white or the Interlux Tri-Lux white on a trailered boat . its almost the same color as the hull gel coat.
 

alldodge

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I would stay away from any kind of bottom kote, it is designed to be removed over time. I would suggest epoxy (as mentioned previously) or some kind of enamel like WOG mentioned (tractor paint) on one of his write up.
 

ahicks

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I had a terrible experience with white epoxy paint on a boat quite a while back (mid 90's?). Not knowing any better I spent days prepping and then spraying the entire top sides of a 26' sail boat with white epoxy based paint - name brand stuff. Needless to say, was pretty disappointed when the white paint started yellowing the minute it saw sun light. Within a year, it looked worse than what I started with. Not talking about something you have to get your face right up to. This was easily visible from 100 yards. Needless to say I had to repaint, again. Expensive lesson from a time wasted stand point, as well as cost of materials stand point. After that, I wouldn't even consider using epoxy based paint on a boat's exterior. Not for a top coat anyway. That's me though....
 

alldodge

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Sounds like you painted the top side with below water line paint. VC performance says right on it that it is for below the water line one, it has no UV protectant. To paint top side, other types (enamel, epoxy and other) are used
 

dingbat

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I would stay away from any kind of bottom kote, it is designed to be removed over time.

That’s the beauty of it....no build up from successive coats of paint to remove

The ablative properties allows you to quickly and easily “wash off” any stains and trailer rash with a scotch brite and water, eliminating the need for succesive coats of paint to appease the eye.

Bottom paint takes and absolute beating on a trailer boat. Enamel is hard enough to keep in good shape on a floor or gunnwale application. Can’t imagine how scraped up and scratched the bottom would be after just a few trips.
 

ahicks

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Sounds like you painted the top side with below water line paint. VC performance says right on it that it is for below the water line one, it has no UV protectant. To paint top side, other types (enamel, epoxy and other) are used

Prior to investing the time and money to do that, I did spend some time checking it out. It was a well known, name brand, 2 part epoxy based paint. Not a bottom paint, and there was no hint anywhere in the documentation there would be an issue when exposed to UV.
 

dingbat

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Prior to investing the time and money to do that, I did spend some time checking it out. It was a well known, name brand, 2 part epoxy based paint. Not a bottom paint, and there was no hint anywhere in the documentation there would be an issue when exposed to UV.
Epoxy paints and coatings are well known for their poor U.V. resistance (chalking and yellowing).
There have been some advances in UV protection but components are specialized and very expensive. Polyurethane coatings are a much better product for use on a boat.
 

ahicks

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My point exactly. That, and the fact that unless you're an "insider" that tid bit regarding poor Epoxy UV performance not widely known. It SHOULD be!
 
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