I have been making some parts with hand lay, with EL2 epoxy slow. Now after curring sometimes the parts stay a bit sticky on the surface. I am guessing it has to do something with the temperature while curing the part. I am currently trying to get the room up to temperature while curring, but what can I do about those parts that stay sticky? I don’t prefer to make them again...

Epoxy is effected by temperature so ideally get it up to 20C for the best results.  Slow hardener can take quite a while to cure fully at lower temperatures.

Permanent tacky patches can be an indication of poor mixing in the bucket.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thank you for the reply, I am very positive about my mixing. I think it must have something to do with the room temperature. Is there a good way of curing the parts that are still a bit sticky? Or will they cure eventually?

Hi is there any update to the last question, I have the same problem. Is there any fix for these odd sticky patches? I've got a room heater on, but how long should one be waiting before all hope is lost of the patches curing and then resorting to taking remedial action ........ if there is any? Thanks.

You need to get them fairly warm, as now they don't have the heat from the exothermic reaction to help. Mid 40's for a day or so should sort it out, or if you can get it as high as 50 then it should only take a few hours. 

If that's doesn't make it go hard then it isn't a temperature issue and will have been a mixing issue.

Thanks, it has like a skin on top in places, this skin is tacky places, the majority of the surface is fine and it appears to be solid underneath this skin. I have a small atomiser spray unit, it has been unused. This may sound silly, but if were to spray the surface with hardener would that be a possible solution? I am almost at the two day period since mixing and pouring.