I'm in the middle of working on a CD 10 and need some info with fiberglass work. I believe that the gell coat had been painted over with a type of epoxy but cant be sure its not just re gell coated. the whole bottom is crazed and my question is can I mix up some polyester resin and roll it on to the whole bottom. Sand and then paint with an epoxy pain like awlgrip or other. Still don't understand if those epoxy paints can go below the water line. I have only read about it being used above water lines. And if I can roll it what type of sleeve for the roller.
Lastly what exactly is gell coat. I think I understand it to be just colored polyester resin. Is this true?
Thanks Adam
Help with fiberglass work
Moderator: Jim Walsh
gel-coat needs to be used in a mold so air willnot contact it
it willnot cure if exposed to air
epox should be fine underwater esp in a dink that willnot stay in the water
btw awlgrip is a urothane not epoxy
but should work
to roll awl-grip use a very short nap roller
and DONOT go over the work once applyed
but best results are from spraying it [realy hi-gloss]
I would fill cracks with micro-ballons / resin mix and sand smooth
before painting
and just use a hard bottom paint if you plan to leave the dink in the water for any longer then a day or two at a time
it will fill cracks better then a glossy finish
it willnot cure if exposed to air
epox should be fine underwater esp in a dink that willnot stay in the water
btw awlgrip is a urothane not epoxy
but should work
to roll awl-grip use a very short nap roller
and DONOT go over the work once applyed
but best results are from spraying it [realy hi-gloss]
I would fill cracks with micro-ballons / resin mix and sand smooth
before painting
and just use a hard bottom paint if you plan to leave the dink in the water for any longer then a day or two at a time
it will fill cracks better then a glossy finish
-
Guest
Gel coat
Gel coat is a heavily pigmented polyester resin. It must be sealed from air in order to cure. If left exposed to air while curing it will never be tack free. To put gelcoat on the outside of an existing hull you need to go thru a multi step preparation procedure and after spraying the gelcoat spray a coat of PVA or similar to keep from contact with the air. Quite frankly spraying gelcoat is a lot of trouble.
CD was famous for using a very heavy gelcoat layer which is prone to cracking and crazing.
I suggest if you have something of unknown origin on your boat the best policy is to remove it completely before painting or gelcoating. Not what you wanted to hear I am sure since this probably involves a lot of sanding.
A second option is to try your fix on a test spot and see what happens. Polyester will not bond well to epoxy, but epoxy will bond to polyester. Some paints have solvents which will dramatically damage other previous coatings. Once you put epoxy on something you are pretty much stuck using epoxy forever. Many paints do not stick well to epoxy so be careful what you select if painting is in the future.
By the time you fill the cracks with something and sand it all level, you could just sand it all level in the first place.
Boyd
s/v Tern
CD 30 MkII
Fort Lauderdale, Fla.
CD was famous for using a very heavy gelcoat layer which is prone to cracking and crazing.
I suggest if you have something of unknown origin on your boat the best policy is to remove it completely before painting or gelcoating. Not what you wanted to hear I am sure since this probably involves a lot of sanding.
A second option is to try your fix on a test spot and see what happens. Polyester will not bond well to epoxy, but epoxy will bond to polyester. Some paints have solvents which will dramatically damage other previous coatings. Once you put epoxy on something you are pretty much stuck using epoxy forever. Many paints do not stick well to epoxy so be careful what you select if painting is in the future.
By the time you fill the cracks with something and sand it all level, you could just sand it all level in the first place.
Boyd
s/v Tern
CD 30 MkII
Fort Lauderdale, Fla.