I applied some coating resin to a part about 2 weeks ago.  and even now it is still slighlty tacky to the touch.  Weirdly the excess resin in the mixing pot seems to have cured fully and is not tacky.  I used a digital scale and am pritty sure I mixed it 2:1.  The part is made from glass cloth and EL1 laminating resin.
Any idea what could be the cause of the tackyness, and any way I could salvage the part?  It took me quite some time to make the part so I'd really hate to have to toss it.

what temperature are you curing that part? must be over 15C° at least!

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

I left it in the workshop which was about 10-15 degrees and then after a few days I left it on a rad for a few days, but it's still tacky
Never had this problem with the West 105/205 resin system I've been using for several years beforehand.

Anyone have any clue why my resin on the part has not cured properly.  I think I'm going to have to toss the part and start again which is a bummer but I don't want to have the same problem again. 

You have eliminated the temperature suspect so the only thing that remains is that you didn't get the mixture ratios correct.

Epoxy shows no mercy when mixing is not right on. Its even harder to get it right in small mixes. I know I have done it my self. I am now mixing to the 1/10 of a gram religiously and have not had a repeat of this problem.

Hope this helps.

Fred  

Even though I was pritty sure I mixed it right, perhaps I accidentally mixed it 5:1 which is the ratio I used with the west system resins I've been using for years. I use a digital scale which is accurate to 0.1g so I can get even small batches accurate.  I think I may try coating a few bits of scrap wood to see if I can get it right without trashing any more parts.

Dear Leew,