Epoxy resin caking up

[DanielGelinas]

Hi guys
I have new bottles of 45 and 30 minute epoxy that are now unusable because the resin has become solid or jelly.
Have any of you seen this before??
That's a new one for me!
I have six year old bottles of brodak epoxy that are still fine!
Is there anything i can do to "fix" the resin?
Many thanks!
-Dan

[goozgog]

Hello Dan,
              This is something I didn't trust
until I saw it for myself.
   I'm talking about "West system" style
slow epoxy where the "golden syrup" hardener
still seems OK but the resin has turned into
white crystals.
  Spoon out what resin you need and put it in
a cut off soda can. GENTLY warm it with a
hot air gun and stir if you have too.
It will go clear quickly. Don't breath the fumes.
Add hardener and use normally.

  I don't know if I'd use old resin for a main spar on
a full size aircraft but it seems 100% to me for
our needs.

Cheers!
 

[john e. holliday]

You say new.  How new?   If bought recently take/send them back.   I had a can of Epoxy paint that I returned to the store as it was one big blob in the can.   This was not the hardener either.

[Gerald Arana]

I have a couple different epoxies over 20 years old (Saftypoxy and Can't remember the name of the other one) that I use from time to time. They both jell in the can. I heat them up on the stove (Don't tell my wife) on LOW and as soon as I can shake the can to see if they are liquefied I remove them and use as normal. Haven't noticed decrease in strength.......

But then again, I like to get by as least expensive as possible..

Good luck and don't burn your house down.

Jerry

[Phil Krankowski]

Double-boiler should do the job of heating.  Just remember using warmed epoxy will kick quicker and much more vigorously. Try to allow the epoxy to cool to room temperature before using.

Phil

[Perry Rose]

When Sig was still Sig they said to just warm the epoxy and use it. I put a bottle in the micro wave for a few seconds and it reverted back to a liquid and stayed there.

[Steve Fitton]

What Perry said.  Heat it gently but very thoroughly, till all the whitish flecks of crystallised epoxy are melted back into liquid form.  Then remove from heat and it should stay liquid.  If it recrystallizes you didn't get all of them the first time.

[Gordon Van Tighem]

The technical mumbo jumbo-

http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_00cb/0901b803800cb76b.pdf?filepath=%2F296-01652.pdf&fromPage=GetDoc

[Randy Cuberly]

Microwave for about 10-15 seconds or less usually works fine.  It doesn't outgas much if you don't get it very hot.

As stated before let it cool to about 70-75 degrees before using.  It should stay liquid for a song time (as in months)  I don't think there's mush deterioration in strength for our purposes.  Should the hardener do this throw it away!  I've only seen this once and that was a long time ago!  Don't heat the hardener.  It outgasses nasty stuff at relatively low temps!

Randy Cuberly

[DanielGelinas]

Hi Guys,

Thank's a lot! I'll try these tricks. Will save me money and time...

Regards,

-Dan