RE-painting gelcoat

simon barefoot

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Well, Barefoot (1981 Princess 37) is out of the water at last! Now the work starts. Theres a jobs list as long as anyone elses... but one of the first that I need some advice on is the paint job.

Before I bought her she had been painted from the waterline to the gunnels. This is now peeling badly. Obviously I have to remove the loose, and try and ease any edges where the loose has been removed, then key up what is left. Then I re-paint. But with what?... And any advice/do's and dont's in terms of application.

I'm totally open to any advice or suggestions for an alternative course of action, however, budget is paramount.

I'm going to start keeping a photographic record of what and how I do things and try and start a blog on here to maybe serve as a refernce for anyone else. I'll do a more thorough search in the next day or two as I'm sure these questions have been answered in depth before, and I know how boring it can be posting the same advice time and time again!!!

Thanks for any suggestions,
Simon.
 

Simondjuk

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What approach you take all depends on how good a result you want and how long you want to spend getting it.

If you want to do it properly, you'll need to get all the old paint off, not just the loose stuff. Then fair the hull, prime, fair again, prime again, flat the primer, and then paint the finish coat. 95% of your time will be spent on prep, the remaining 5% actually putting the paint on.

It's hard to be sure as it was a job which was picked up and put down week to week as the weather allowed, but I wouldn't be surprised if 100 hours went into refinishing our boat from starting to take off the old paint to removing the last bit of masking tape after applying the new top coat.

I used International Perfection 2 pack. It's not exactly cheap and is particularly hard to work with. It's water thin so it runs incredibly easily yet goes tacky so fast that it can easily get draggy between rolling it on and tipping it off. On the plus side, it is incredibly hard and gives a good gloss straight off the brush.

We took the first coat of primer back off because I wasn't happy with it, as if the surface shows any imperfections when it's semi-gloss, it'll look horrendous when it's gloss. You've been warned!

Since doing the job, quite a few people have assumed the boat has been professionally sprayed, which is nice.

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PCUK

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I think Simond may be overstating things based on his own fabulous job which took a lot of prep'. If the surface is good then preparation will be stripping off all the old paint. Dilunette is good if the paint is single pack which it sounds like. The wash with solvent, lightly sand, fair and sand again. Then using a pad, Epoxy prime, followed by two-pack undercoat and and well thinned two-pack, topcoat twice. Result should be near spray finish.
 

doug748

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Have a critical look at the hull, is there any damage to the original gelcoat? If you are pretty sure there is none, the cheapest thing to do would be to remove the offending paint and renovate the gelcoat.
There are lot of poor paint jobs around that have been applied over a decent original finish. One of the young lads in the boatyard bought a badly painted yacht took off the paint and polished - it looked excellent.
My golden rule is think very hard before you paint and, unless there is damage, don't do it.
Like rib, I have seen a lot of good regelcoat work.
 

chinita

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That is very interesting.

I am currently debating when to apply new paint to my (already painted) hull. I curse the person who did this as I am a firm believer that most gelcoat can be compounded and polished back to good cosmetic appearance.

I have never heard of, or seen a boat which has had paint stripped from the hull and the original gelcoat polished.

Is there anyone else out there who has done this?
 

doug748

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Yes, I seem to remember he used a scraper to remove the paint, it was flaking in parts. Hard work but so is repainting if done properly, as in Simon's excellent example above.
 

ghostlymoron

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I painted over an existing paint job without doing much apart from keying the surface with fine grade wet and dry. I then applied one pack International with a roller. The finish wasn't top knotch but I was more interested in sailing than painting. I wasn't complimented on my painting skills but she was beautiful in my view.
In retrospect, I should have stripped the original paint off and renovated the gelcoat.
 

Slycat

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Touchup

On a similar note I have a few scuffs on my hull above the water line where fenders have rubbed off the paint (about the size of a palm).

I don't want to re-paint the entire boat this season, any tips for what to use just to touch up the scuffs?
 

rib

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boo2.two and half thousand pounds last year,fantastic job and it takes out all the odd knocks as well,two very dedicated guys(thay did run over time some what but never complained or asked for more money)thay are in the west country dont know if thay will travel.pm me if you want more info im not giving their names or numbers out on here in case thay dont like me to
 

rob2

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I wonder why the paint is flaking? It is difficult and time consuming to prepare GRP for painting, particuklarly as most hulls have some of the release wax remaining on the surface or even rubbed into it whilst polishing. such contaminated areas will not allow the paint to bond properly and it will flake or peel off.

If you are considering repainting, you should go back to gelcoat first, at which point you can decide whether the original surface can be refurbished.

Rob.
 

Scotty_Tradewind

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From listening to others over the years, painted gellcoat is usually hiding something otherwise why have it, as it devalues most boats.

If it must be done, then get right back into the gell so there is no doubt as to a good priming surface and use a quality 2pack paint..

If you get all the paint off and there is no significant damage, why not then polish the gell in a small area to see if it may be done all over.
 

rib

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simon just noticed your in cornwall if you want to pm me you can have his number he will give you good advise on what to do,you have to be carefull how coarse a paper you use if theres any chance to polish it after
 

craic

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From listening to others over the years, painted gellcoat is usually hiding something otherwise why have it, as it devalues most boats.
....

I would disagree. If done well, and done only in areas where there is no permanent abrasion from walking etc. I think a paint cover is no devaluation.

I have two GRP boats with a dark coloured gelcoat outer. They scratch so easily, visibly and permanently, I very much regret my choice.
Then I learned how easily the gelcoat fades from sunlight. One boat with a racing green hull soon got milky patches on the sunny side. And then what?
And then recently I got into a bad collision, a yacht racing at full speed on port bow ploughed into me, and that repair is a nightmare not so much in terms of mechanics but due to the colour variation of the old and the new gelcoat. I really find colour gelcoat very delicate.

Then on the other side I have one epoxy-ply boat with a Mauritius blue painted hull, and whenever that gets a scratch or hole, I just mask the area, and paint it over, perfect.

Now my next GRP boat will come with a white hull, and I will paint the topland with a two-pack, so as to give the hull a colour appearance, but one that can be easily repainted or repaired.

On a side note, I am actually considering to use adhesive film on the topland instead of painting it. I have been in the signmaking industry, and there are amazing things you can do with self-adhesive film these days, lasting many years in a tough marine environment no problem. Imagine, just peel off an old coat and put on a new one. And no arguable devaluation of the gelcoat underneath.
 

onesea

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Self adhesive film? This sounds interesting...

I guess the big questions are cost per year? Total price/expected lifespan?
Is amateur applying possible?
 

Boo2

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boo2.two and half thousand pounds last year,fantastic job and it takes out all the odd knocks as well,two very dedicated guys(thay did run over time some what but never complained or asked for more money)thay are in the west country dont know if thay will travel.pm me if you want more info im not giving their names or numbers out on here in case thay dont like me to
Sounds like a fair price for the size of boat but they're probably too far from ne to be worthwhile. I will probably just have a go at filling and fairing my minor stress cracks for now and see about re-gelling later if it doesn't turn out well.

Thanks for the info,

Boo2
 

simon barefoot

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I think I will strip the paint, but the existing primer is rock solid. So maybe apply new primer over the old, and paint over that. Unless that is a major no-no?
 

chinita

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How would the panel advise stripping off existing hull paint from gelcoat to leave it in a satisfactory state for compounding and polishing?

I have done this on my wooden boat many times but never on GRP.
 
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