This is something few people even consider when doing fibreglass work ! regardless how big the job or how small . humidity can be a killer . Any one had any bad exsperiances they want to share ??
As the years have gone by the resins we use these days are better and stronger than those of old BUT they are not as forgiving as the older resins and are more subceptable to differances in temprature and humidity variations . This can and does have a big differance on the gel times and cure of most all resins . Damp glass and the resin goes off slow and has a opaque look in bad cases , even though the temprature is the same as last time you glassed the humidity could be much higher and slowed the resin gel time considerably . Spraying materials ,as the sprayed particals travel though the air they pick up moisture on the way from the end of the gun to the job . Chopper guns specially . because they have catalysed resin and glass at the same time . Hand lay up can simply be the roll of glass could be damp . Its been laying on the floor and drawn condensation up through the concrete. so even though its in a plastic bag the bag could have moisture on or in it .
Stack rolls on a old pallet on plastic if you have a lot of glass. smaller quantities up on a wooden bench were air can circulate constantly . Better still a proper dry air cupboard with a dehumidifyer in the bottom .