I just recently returned to the r/c hobby and have started assembling some ARFs. Last night I joined two wing halfs with epoxy. This morning when I examed the wing it appeared to be solid however the plate that had some left-over epoxy was still slightly tacky. In looking at the bottles it appears that I used the correct portions of epoxy and hardner. What gives?? Ihave used this glue before with no problems. Will it eventually cure? Thanks in advance for your help.

A quick look at Weatherchannel.com say your Humidity level is at 76%. High humidity and cool temps. can slow the cure times of paint and exopy.
I bet by the end of the day it will be fine
LMK

Heat will speed up the cure, don't get it so hot it would burn you to the touch though, just around 120 to 140 degrees Farenhite for a couple of hours.

I don't think the cold or humidity is to blame. I am sure the joint you expoxied is perfectly fine. What I have seen, is that at the very bottom of the mixing surface, you don't always get the epoxy and hardener completely mixed and it doesn't cure. However, the expoy you used in the joint is probably mixed well enough to cure properly. When you mix epoxy, use different patterns of motions every few seconds so you all the epoxy mixed, all the way to the edges AND to the bottom.

Thanks guys for your input. I will do a better job of mixing the next time.

Epoxy Cure?
Take two bottles of CA and call me in the morning.....yuk-yuk-yuk....

Sorry, couldn't help myself!

Just out of curiosity, What brand of epoxy?

The stuff that Hobbytown sells.

Did it Dry yet??

Not yet. It's still a liitle tacky

I'm still a little tacky too, and I'll never be cured.

Was this, by any chance 5 min epoxy? Many years ago i used some 5 minute stuff that was old and it never cured. If it was 30 min or more, don't worry about it, it will eventually cure. A little heat will speed it up. If you can... set it on top of your furnace or someplace warm like that (providing you don't have some sort of Frankenfurnace that will set it on fire). Or hit it with a hair dryer or heat gun.

What I like to do to get the mixture correct is use one of those double tubes of epoxy, the ones that will eject the base and hardener simultaneously. I only buy a few, use what is in it and just keep refilling them, one with 5 minute, one with 15 and one with 30. Make sure you refill the correct tubes, mark them A and B if necessary.

Yea I had that problem last week w/ 90 sec epoxy.And it's still tacky!
BNZ'