Changing colour of gelcoat question

[carlos515]

Do I need a gecoat primer if I go all white gelcoat over my coloured hull? I was thinking to make the boat all white with a graphics decal to add some colour and style.

 

[alldodge]

See is @MikeSchinlaub can advise

 

[MikeSchinlaub]

Nope, just spray directly over the old gel. Actually, you could also paint it with either base and clear or single stage. It would be easier than gelling the whole thing, and getting gel too thick will make it more likely to crack.

You can paint the top and sides, but avoid the bottom and around the tie downs.

 

[carlos515]

Thanks, I have sprayed cars before, the single stage would be easier as I do not have a paint booth.
Why avoid the tie downs?
Would you suggest a primer for the single stage?

 

[Scott Danforth]

No. See the boat in my sig.

More here. Including spraying gel.
https://www.boatdesign.net/threads/gelcoating-the-whole-boat-down-to-the-waterline.61694/

 

[MikeSchinlaub]

Why avoid the tie downs?

Because the roller up front and straps at the rear will damage the paint. You could put pads behind the rear straps though.

No need for primer. The gel provides a good base, and single stage is thick enough to fill minor scratches. Just sand it all with 220 and clean it well.

 

[carlos515]

Thanks lads.
I have a gallon of Duratec. I think some testing with white gelcoat is in order after my interior work. My idea is to spray the entire boat white. Add some graphic decals on the sides of the hull. Now I am torn with spraying the sides a metallic blue, which I have a gallon of single stage at home, or white gelcoat with vinyl graphics added. I was looking at a site that has some nice vinyl designs.

 

[carlos515]

Just out of curiosity, does humidity take the gloss sheen out of the gelcoat with Duratec in it?
I know with auto paint it will.

 

[Scott Danforth]

You will get some orange peel. So you will be sanding and buffing

 

[carlos515]

Thanks, Scott.

 

[carlos515]

How many sq feet does a gallon of gelcoat do per coat on average?

 

[MikeSchinlaub]

To do the hull and cap, I would say you're going to want a 5 gallon bucket. Gel needs to be really thick to cure right.

Think high build primer, double the thickness of each coat, and do 4 or 5 coats.

 

[carlos515]

Thanks, Mike,
I take it that the last coat would be mixed with the Duratec?

 

[MikeSchinlaub]

Scott will have to answer the Duratec question. We use a different product at work (patchaid, which is styrene wax).

Get a price on that gel before you get too far though. Since you already have a gallon of single stage on hand, I would suggest using that if you're happy with the color.

 

[carlos515]

Thanks, the 5 gallon pail of gelcoat is expensive. I think the top cap will get gelcoat along with the bottom of the boat. I figure 2 gallons would be enough.

 

[Scott Danforth]

if you think Gel coat is expensive. I looked into repainting my boat with Axalta (marine imron). the red alone was $796 a gallon my cost thru work (we sprayed about 1500 gallons of Axalta a year). it would have been over $2500 to paint. I did my whole boat with 2 gallons of white gel, 3/4 gallon of blue, and a quart each of grey, black, and red. I think I spend about $700 on gel and 904

my outdrive is a custom mix of rustoleum oil base with a bit of hardener.

 

[carlos515]

Yes, I priced Imron before. The 904 would only go in the last coat? If so, I might get away with 1 gallon of 904....that would make the 5gallon of white gel with it 700.

 

[Scott Danforth]

904 goes in every coat, unless you can live with lot more orange peel

I even put it in the custom mix I did for the nonskid

 

[carlos515]

Ok, thanks. That would be 1k for 904 alone. Time to decide whether to do top cap and bottom of boat with gel/904 and sides with single stage.

 

[Scott Danforth]

You can do your whole boat with 1-1/2 gallons of white and 1-1/2 gallons of 904.