jetlag1

Yesterday I mixed 2 batches of 30 min epoxy while trying to glue the tail of my arf. both times the mixing cup smoked a bit and the mixed epoxy turned yellow and hard within 2 minutes. Actually set so fast the horizontal stab is about 1/4" off center before it would not let me move it any more. Never seen anything like it

Geistware

My Feedback: (16)

SOunds like it had a reaction with the mixing cup.
What is the cup made out of?

jetlag1

it is one of those mixing cups you buy from tower or horizon. It allows measured amounts. I must say both had been used before(cheap of me) considering I have a whole pack of them

pete913

I've run into that a couple of times myself. I was using some small plastic cups from the grocery store,,, cheep cheep cheep. Paper ones work well, I just can't find 'em normally. Epoxy in a big mass will do it too, best to keep it spread out thin, like on a paper plate, if you can, it doesn't get hot then like in a cup.

jetlag1

thanks, these cups are designed for mixing so it kinda surprised me to see the reaction. I remixed on another mixing cup and the same results. By then I was scrambling to get the tail in place . I had previously used them, however I do no think that had anything to do with it

gwk

I use a polyproplene cover from coffee lid covers. Just spread two equal lengths of parts a and b, mix completely. After the epoxy cures you can just flex the lid and the epoxy will just fall off. You can then use the lid again the next time.

Azcat59

I assume you had used this epoxy before? If not, it could be that the hardener was for 5 minute epoxy instead of 30 minute. Test some in a flat amount as noted in the above posts and see if it sets up fast....if so, you have a chemical problem I think.

Clair

CafeenMan

how much did you put in the cup? If you mix too much it will get very hot in a small container. Larger quantites should be mixed in shallow, wide containers - like tuna cans. If you use a 1 ounce medicine cup, never fill it more than about 1/3 full.

FHHuber

If there is residual semi-cured epoxy in the cup... it can kick off the fresh epoxy almost like super-glue being hit with accelerator.

( a very good reason to not re-use a cup that has not been THOUROUGHLY cleaned....)

Geistware

My Feedback: (16)

Why I use is a paper pad for writing notes (bigger than postits). I just tear off a couple of sheets and then it is ready to use again.

Azcat59

I use the cards that come in junk mail. Just run a strip of part A, and a strip of part B beside it, and mix it up. Or three strips of each, etc. for whatever is needed. Junk mail IS good for something!

Clair

voyager_663rd

paper cups--what about those you find at mickey d or b.k. for putting ketchup in?

jetlag1

thanks all for the replies. I was out of town on business for the last couple of weeks. Yes it is the same epoxy I have been using and yes if I mix less of it in the mixing cup it works fine. So it seems to happen when you mix too much of it in a deep container as some of you pointed out. Last 2 batches worked fine, however I mixed a much smaller amount. Again thanks for all the help

wilinfla

My Feedback: (5)

I just recieved an E-mail from Tower Hobbies about a recall of their 30 minute epoxy, it was mis-labeled, it was actually 6 minute epoxy. Were you using Tower Hobbies epoxy?

spokman

My Feedback: (2)

Actually its GP 30 minute that's mislabeled. Might as well be tower though.. If it caused problems on your plane I would gripe.. I'm ticked but I work fast so I just thought I mixed it hot..

darrentpi

I use 30 minute all the time, and what I use, is those pocket note pad booklets, you can by for cheap, and I do all my mixing on that, and then tear off a page when I'm done ready for the next batch. I also find those wooden stir sticks, you find at you local coffee joint, come in handy for mixing. Grab a few next time you go for a coffee.
DM