Any ideas, other than dig it all out and re-do? It's a fairly large section. Put in the recommended hardener but it was possibly too cool for that, it started to tack but never went hard. I spread a thin film of hardener on the surface and heated it up to 30C or so and it went fairly firm to hard, but has kept a soft surface. Trying to decide whether I have to dig the lot out or if it can be rescued!

Usually if a thin coat of 'strong' filler is applied over the top, the catalytic reaction turns the dodgy filler too - it can sometimes take a few hours though.

had this many times in the winter

get a hair dryer and heat it up till its too hot to touch, the surface will then become hard once cooled down. Usually it turns quite a bit darker as the curing process starts up. Same thing can be done to GRP is it has not gone off properly.

It is also best to buy anti clogging sand paper when dry sanding in the cold weather as this lasts a lot longer

oh and don't put hardener on the surface that will just make a mess and won't mix in anyway

[Edited on 14/2/11 by Mr Whippy]

Some more thoughts

Here

Cheers

Fred W B

I wouldnt chance it. dig it out and start again.
You wouldnt want it to move under the paint