Degreasing oily bilge for GRP repair.

[fisherman]

For awkward amd vertical areas I always lay up on a board away from the job, 3 x 600gm csm at a time, any more risks heating. Pick up with brush and roller and push into place.
I am careful with catalyst %. A local GRP car panel man had a chart on the wall of ambient temperatures and ratios of accelerator and catalyst. He also weighed everything and never had leftover resin.

 

[mogmog2]

Thanks everyone. I'll use a heater to dry the area and warm the substrate a bit in the days preceding the operation. I will also use the heater to keep the temperature up during curing. Will it be ok to turn the heater off (when I leave the boat for the day) and back on again the next day or is there not much point?
I plan to use woven cloth, with the layers' orientation alternating 0 and 45 degrees and balanced (0,45,0,0,45,0) as appropriate and the importance of fairing/tapering etc has been taken on board. Would biaxial cloth be better and I was advised to go lighter rather than heavy with the cloth weight. 10 thou was suggested, but I can't find a translation of that, to weight. Thoughts? I'll investigate the resin options but I understood that epoxy gave the strongest bond to old polyester substrate. I haven't got loads to do, so the cost is not a big issue: it is tabbing for an existing gusset, a run of about 30cm and whilst I'm at it, there's a less critical 'furniture' run of about 45cm where the locker is sealed against the cabin tub moulding.