Gelcoat:A newbies question?

Discussion in 'Materials' started by d_sinsley, Jun 27, 2007.

  1. d_sinsley
    Joined: Jun 2007
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    Location: idaho

    d_sinsley Junior Member

    Hello,

    Im sure what I am going to ask has been asked and answered a hundred times. I am getting ready to start a restoration project on my Chrysler 22 Sailboat. This will be a keel up restoration, starting with the Hull. I am leaning towards re-gelcoating the hull as to painting over it. This is a trailor moored boat and I am not concerned with the need for bottom paint. I figure with gel coat I am starting with a more permant solution as opposed to covering up a problem. Is my thinking advisable and what type of gelcoat is sprayable and air cured and who are some suppliers that I can purchase from.

    Devon
     
  2. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Firstly, welcome aboard bd.net :)

    Re-gelcoating tends to be done only when the original gelcoat is so badly damaged that the hull's resistance to water is in danger of being compromised. If it's not badly cracked or missing chunks, re-gelcoating is probably not necessary. The stuff is brutal to work with and needs a professional touch, unless you like the Salvador Dali look (runs, drips and distorted surfaces). And, gelcoat fades and cracks in short order no matter how good it is and how well you take care of it.
    Marine paints, especially modern urethanes, last a long time without fading and are quite durable and waterproof. Plus they can be applied by roller/brush, with a bit of patience you can get a pro quality finish. If your gelcoat's more or less intact, just faded and ugly, a good prep job and a few coats of primer & paint will do the trick.
    You're right to skip right past the antifoulings if it's a trailer boat. They are designed to be left in the water for months on end and will do next to nothing if the boat is on land most of the time.
     
  3. d_sinsley
    Joined: Jun 2007
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    d_sinsley Junior Member

    ok you answered the question along with other threads I have read. Its just plain old and ugly. Actually the intergrity looks fine. So paint it is the answer. I figured this out on my own really but am stubborn. What should be done to prep the boat. It has old bottom paint, gel coat and who knows what kind of paint for a stripe. Can I just get after it with a sander and if for some reason I get carried away and get down to glass, then what?
     
  4. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    A random-orbit sander (air or electric) will get the old paint off; a belt or spinning-disc type will probably give you trouble. Drop the coarse grits as soon as you can see a significant amount of gelcoat through the sanding scratches, then switch to something in the 200s until it looks a fairly uniform colour with no old antifouling. Don't get carried away; you're only looking to get the wrecked antifouling coats off. Follow that with something around 320-400; from there on, follow your paint supplier's instructions to the letter (they usually call for a fine sanding, then a wash with dewaxing/degreasing solvents, before priming).
    The gelcoat is not really a coating, so much as the outer layer of the fibreglass hull- it's just a special type of fibreglass resin, without the glass cloth embedded. If you go through it, you'll be sanding into the structural skin of the hull and opening up pores where water can seep in.
    You MUST wear a good, properly fitted dust mask (N95 equivalent or better) when sanding the old paint. Antifouling dust is toxic.
     
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  5. d_sinsley
    Joined: Jun 2007
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    d_sinsley Junior Member

    your help and advice is excellent, thank you.

    Devon
     
  6. Abrasive Dan
    Joined: Jun 2007
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    Location: Philadelphia, PA

    Abrasive Dan New Member

    Hey,
    Long-time reader, first-time poster. You might want to look into Mirka's Abralon product or Webb Abrasives' Air Velvet, d_sinsley, for a good sanding disc to use.
     

  7. d_sinsley
    Joined: Jun 2007
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    Location: idaho

    d_sinsley Junior Member

    will do
     
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