Using Gelcoat

[Rich_F]

I've been kindly given a pot of colour-matched gelcoat for my topsides, but I'm not sure what to do with it!

Firstly, what sort of hardner should I use, and in what ratio? Where can I get it?

Secondly, I understand that it doesn't cure properly if left exposed to the air, so should be sealed under a plastic film. Given this, any suggestions how to repair the lip where a circular drainage hole emerges through a vertical surface. It's not easy to seal up compound curves with flat film.

Thanks for any help,

Rich

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[Evadne]

Sorry, can't help with the hardener ratios but to seal up a compound curve, why not try making a mould from putty and coating it with clingfilm?


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[Rich_F]

The forum delivers once again!

Good suggestion. Thank you.

Rich

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[Paul_H]

Catalyst for poly resin is liquid MEKP mixed 2% by weight. For small amounts buy it in a dropper bottle which will usually idicate how many drops per mL resin. Most chandlers will stock or try Blue Gee GRP in Poole 01202676612
Depends if youve got plain gel or waxed gel. Plain gel is used for moulding cos the surface is sealed from air inside the mould. Waxed gel is used to overcoat and will cure in air. Waxed gel is usually brushed/rolled to give a rough finsh (eg inside hull and lockers). For a smooth surface repair use tape or film over the gel whether its waxed or not cos it will level the surface and stop the gel drooping. Its also usefull to mask around the repair in case of spills and the thickness of the masking tape ensures the gel is proud of the finshed surface. Use reducing grades of w&d to flatten the repair and then liquid abrasive to finish. Remenber gel is just a thick polyester paint not a filler so the the bulk repair needs to be level and a couple of mm below the finished surface.
Practice first to see how the gel behaves when laying it on and hardening.

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[Rich_F]

Thanks Paul. That's really helpful.

Regards,

Rich

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[BrendanS]

There was a great post on using gelcoat some while back on the mobo forum that I saved in my favourites for future reference:

<A target="_blank" HREF=http://www.ybw.com/cgi-bin/forums/showflat.pl?Cat=&Board=mby&Number=248744&part=1>http://www.ybw.com/cgi-bin/forums/showflat.pl?Cat=&Board=mby&Number=248744&part=1</A>

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[Avocet]

You can sometimes seal a compound curve from the air using plasticine.

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