Old or Out of Date Epoxy?

[Dhutch]

Ive got about a kilo of west systems epoxy in the bottom of a 5kg drum left over from a job i did a few years ago, both hardener and epoxy went out of date mid/late 2004 which is now the best part of 6 years ago.

It still seems to go hard as before and generally behaves ok and ive been slowly using it up on non critical job such as sticking the yard brush together and the like but ive now got a more critical job (actually, repairing the thing i initially bough the epoxy for) and im wondering if i should get some fresh epoxy (say the 1kg 2:1 mix Sp pack, or equiv. west systems?) or if in actual fact the 6yo stuff will be fine and just as strong?

In short, would you use 6 year old epoxy ever?

1kg is £20 so its not money, its just not wanting to waste it.



Daniel

Yes you can use it. It does not loose ot´s properties (at least not noticeable).

Regards
Richard

[Dhutch]

Not even after six years in the garage?

Originally Posted by Dhutch

Not even after six years in the garage?

As long as it had no frost there it should still be ok! We once used 8 years old with no complications (after testing of course).

Regards
Richard

[gonzo]

The only problem can be with the hardener beause it is hygroscopic, if it wasn't sealed. Cold does not affect epoxy. They store it below freezing in Michigan.

The reason why manufacturers recommend to store the stuff above 0°C may be to avoid the build up of condensate?

Anyway, he can use it, thats important.

[GG]

Originally Posted by gonzo

The only problem can be with the hardener beause it is hygroscopic, if it wasn't sealed. Cold does not affect epoxy. They store it below freezing in Michigan.

I agree and always keep everything in the garage and i also live in Mich .

[Dhutch]

Its probably not got below zero much and its not too damp.
- However not as such been sealed, it been in the containers (largely empty) with the pumps on the top.


Daniel

Originally Posted by Dhutch

Its probably not got below zero much and its not too damp.
- However not as such been sealed, it been in the containers (largely empty) with the pumps on the top.
Daniel

You said it cured thoroughly when you did your repair jobs. So, I would not be afraid using it.

[dinoa]

Some manufactureres advise you to heat the crystalized epoxy while stirring to about 60 deg C in a hot water bath until all crystals are dissolved.

Dino

[missinginaction]

dinoa, I've actually done that, and it works. I'm not a chemist but I emptied some crystalized System 3 Epoxy Resin (not the hardener) into a cheap metal pot and used a heat gun to bring the temp up. Worked like a charm.

Funny thing though, I did this a few years ago and since then I've had no problems with any of my epoxy crystalizing. I've no idea why the crystals formed and why they have not formed since.

Regards,

MIA

Originally Posted by missinginaction

dinoa, I've actually done that, and it works. I'm not a chemist but I emptied some crystalized System 3 Epoxy Resin (not the hardener) into a cheap metal pot and used a heat gun to bring the temp up. Worked like a charm.

Funny thing though, I did this a few years ago and since then I've had no problems with any of my epoxy crystalizing. I've no idea why the crystals formed and why they have not formed since.

Regards,

MIA

MIA
you must not understand everything.............

live with it. that is enough.........


Regards
Richard

[dinoa]

I've even heard people microwaving to dissolve the crystals but a water bath is the way to go. Just avoid letting water vapor in the container as it will inhibit the cure but crack the cap open a bit to vent expanding air.

Some manufacturers change formulations which is why you may now not be getting crystalization.

Dino

[Herman]

Moisture will speed up the curing speed, but also will make for formation of bubbles.

Most epoxy resin is guaranteed for 3 years now (resin) or 1 year for hardener. However, the stuff is quite stable, so I do not see any problem in using it.

The pumps, however, might give some problems. Check their accuracy by weighing a couple of strokes (both resin and hardener).

About crystallisation: I decant epoxy from 250 liter barrels into smaller containers. Sometimes from the same batch, one container does crystallise, and the other doesn't.