gelcoat repairs and temperature

[paulburn]

I saw on a website that gelcoat materials are optimized to work at 20 degrees and have a narrow temperature tolerance. Does this mean that in the UK one should only do gelcoat repairs in July and August for best results, or does it not really matter ?

regards paul

 

[boatmike]

You should really have 16degrees C and low humidity for any work on GRP. As Gelcoat is not structural you can go as low as 12 degrees but no lower or it won't cure properly.

 

[oldsaltoz]

We have done repairs mid winter, though that's possibly a bit warmer. The trick is to put a lamp inside that will produce some heat, I use a 150 watt Tungten lamp, let it burn till you are sure the outside is dry, then start sanding, collect the dust to mix with the gelcoat it will improve the colour match.

Leave the lamp on overnight for best results. This method can also be used for minor fibreglass repairs.

Hope this helps.

Avagoodweekend......

 

[paulrae]

I wish that you had posted this a couple of weeks ago - the lamp trick would probably have worked wonders for me.
I've just removed my old antifoul and taken the hull back to gelcoat. There were a few nicks in the gel coat (worst was 3-5cm long, 1cm wide, 0.5 cm deep), so I decided to fill with epoxy gelcoat filler prior to priming with Primocon. It was pretty cold (5 deg C) and the filler on the larger nicks wouldn't set. In the end I had to leave it a few days before sanding down and priming.

 

[oldsaltoz]

Sorry you missed out Paul,

I should have added:

Resin should be warmed, standing in hot water is fast.

Always stick some tape above the repair site with the lower edge hanging off the boat, this will ensure any rain or condensation will not run over the new work before it cures.

Hope this helps.

Avagoodweekend......