Problem with old gelcoat: restore or paint over?

Discussion in 'Powerboats' started by Jonny88, Jun 19, 2011.

  1. Jonny88
    Joined: Oct 2010
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    Location: Plymouth

    Jonny88 Junior Member

    Hi all,

    I have a Picton 170 GTS that I'm doing up as a project.

    It's had some knocks in it's time and as a result it has some pretty deep gouges, scratches and cracks in the gelcoat. Further to this it also has at least 2 maybe 3 layers of old antifoul on it under the waterline.

    I'm wondering what my best course of action is to restore this back to as close to it's original state as possible?? The antifoul is definitely coming off as I won't be keeping it in the water and I'm keen to get that old "gelcoat look" back. The boat been completely stripped out inside and I can have it upturned to work on so practicality isn't a problem.

    I've heard of people painting over their gelcoat with a 2 pack paint that comes out "like gelcoat". I don't know how restorative/re-storable (spelling?) gelcoat is but if I'm completely honest I think it's past it. I'm wondering if I'm best off stripping all the antifoul back and sanding down the gelcoat on the topsides and going for a paint job. What do people reckon?

    Would appreciate any thoughts and comments.

  2. keysdisease
    Joined: Mar 2006
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    Location: South Florida USA

    keysdisease Senior Member

    Pick out a few square feet and do a hard compound and wax on it as a test. 3m makes a heavy duty rubbing compound or from automotive there is a product TigerKut .

    Gelcoat is pretty thick and you may be pleasantly suprised at how well the shine comes back.

    As for the bottom, removing the old antifouling will be a problem. If you sand it off it will be difficult to compound out the sanding scratches. You may want to try a paint remover, the ones with the paper coverings work pretty well but its a messy process. The easiest thing to do would be to sand the bottom paint smooth and paint with one of the bottom paints that have some color depth.

    Painting with a two part product like awlgrip will give you a great finish. It is pretty involved to get right and involves priming, fairing and sanding to get a good finish. Application of the finish should be left to someone with some experience in spraying paints as all this family of paints have very little forgiveness.

  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Agreed, a good compound and buff will restore gel coat's gloss, but it's a diminishing set of returns, as you're physically wearing away the gel coat as you do this. Do the buff job and see what happens, then, if successful and you haven't worn through in spots, keep it well waxed and covered when not in use, so you can keep the shine as long as possible.

    If the gel coat is too thin, from previous buffing or damage, paint is a good option and you have a lot of choices here, but the LPU's are the ticket as Steve mentioned. They are difficult to apply, particularly by the novice, but worth researching (lots of videos, and text on line) as the results rival gel coat.
  4. anthony goodson
    Joined: Mar 2007
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    Location: Dorset UK & Murcia Spain

    anthony goodson Senior Member

    Old antifoul can be injurous to health, take care when removing it,
  5. Chuck Losness
    Joined: Apr 2008
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    Location: Central CA

    Chuck Losness Senior Member

    I have used a product called "newglass2" and it made my old gelcoat shine like new. Myself and everyone in the yard was amazed at how it restored the shine to my gelcoat. It is easy to apply. Took about a total of 8 hours to do the hull of my Gulfstar 37 sailboat. One morning to thoroughly wash and clean the hull and the next morning to apply it. It dries very, very fast and was easiest to apply in shade. I have used it the last two times I have hauled out and will use it again when I haul the boat this October. The first time I applied 5 coats per the instructions. The second time I only applied 2 coats as a touch up. It is only available online to my knowledge. Just google "newglass2" and you will get a link to their website.
    Good luck with your project.
  6. bntii
    Joined: Jun 2006
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    Location: MD

    bntii Senior Member

    Given that your boat:
    I would say it is time for putty and paint.

    The process is easy for the experienced with the sanders and such on hand and not too expensive for a small boat.

    The first timer will face the learning curve and cost of tooling up for the job.

    Grind out all cracks- they will print through otherwise.
    Fill all defects with good quality fairing putty, sand out and epoxy prime the hull.
    Go over the hull with spot filler, sand out the primer to 320 or so and shoot.

    If you are around any marinas which paint, sometimes a painter will contract for the topcoat shoot on a prepped hull.
    Sanding swirls, missed pinholes, chips etc will be 'on you'...

    Yes- use AwlGrip or an equivalent LP paint. The longevity and quality of finish are worth the price of admission.
  7. keysdisease
    Joined: Mar 2006
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    Location: South Florida USA

    keysdisease Senior Member

    The attached is the hull of my trawler at age 27 years after a coumpound and wax ;)


    Attached Files:

  8. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Somewhere between 1995 and 2000 I spray painted my boat with "Veneziani Gel Gloss", a 2-pack polyurethane paint, changing it from dull gray to shiny white.
    The painting itself took maybe 2 hours, the preparation several days.
    Probably next year we'll wax it because the paint starts looking like eggshell, until now we only washed it occasionally.

    I looked at this newglass2 website: why don't these guys tell what it is instead of just telling what it isn't? It is water soluble, yet doesn't wash off and cannot be removed except with their pre-treat product. Sounds a bit like a hoax to me.
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