Talk Composites - The Forum for Advanced Composites

EL2 Epoxy Resin, think I've used wrong mixing ratio

http://www.talkcomposites.com/Topic15898.aspx

By Langforp - 3/31/2015 3:46:42 PM

Hello I am in the process of applying fibreglass cloth & epoxy resin to a fairly large RC wooden boat. I used the Slow Hardener & applied 1 coat through the cloth, allowed it to dry then applied a second coat over the top. This was 5 days ago & it is still not tack free. Both mixed amount remnants gelled very well in the cups, but in lower thicknesses it remained very tacky. I was working with a 2K epoxy primer at the same time as doing this & I think that I may have got mixed up with the different ratios i.e. the EL2 is 100:300 the epoxy primer is 3:1. If this is the case the EL2 would have had about 3% too much hardener added to it. I have tried to dissolve the resin in cellulose solvent to check cross linking level & it is possible to dissolve it with some difficulty. I am now tempted to remove as much as I can by washing with solvent & scraping & then reapplying resin. Does anyone out there have experience of doing this or have any better methods of how to overcome my problem? I have working all my life in the paint manufacturing industry, but have no experience whatsoever of laminating in this way Thanks Peter
By Warren (Staff) - 3/31/2015 5:36:44 PM

The correct ratio for our EL2 is 100 parts by weight resin to 30 parts by weight of hardener.

If the ratio if out, the resin may well remain tacky. 

Initial actions should be to get it somewhere warm ASAP. Ideally 40C or above would help massively. Then leave it a good 24 hours to see if it helps.

If it is still tacky after that then you will need to sand the surface of the resin as best you can and recoat in fresh resin.