Is "Frozen" epoxy useless?

[Seagreen]

Just rescued some West 205 epoxy resin and hardener from my (-3 degrees C) garage to the warmth of the kitchen cupboard. Should I now consider it useless and junk it or is it usable yet unpredictable?

I've had this happen before without noticeably bad results, but the epoxy used then was for jointing and fillets, not layup.

 

[Amulet]

Stand in a bucket of warm water to decrystallise (it, not you), shake it up. West certainly regard it as entirely recoverable. If you use it warm it will set in no time, so get it to a suitable temperature before use. I have a gallon out in the workshop which I'm assuming will be OK. I have done this before with no problem. If you use it cold it will never go off properly. Gougeon brothers claim success down to 7 Celsius I think. I wouldn't risk it that low.

 

[huldah]

Yes, heat is what is required, but it may take some time. Last year I put a pot on the hot enamel of my Aga cooker for some weeks. Was perfect when needed later in the year.

Generally it is better to store in the warm as these crystals can cause fish eye when used as a coating.

 

[Seagreen]

I suppose a slow and gentle thaw on a kitchen cupboard would help, but standing in a tin of quite warm water before use seems ideal.
I've a bottle of Olive Oil on the boat that regularly crystalises only to be revived in a bath on the stove.

 

[30boat]

When I mix a batch and don't use it all I keep what's left in the freezer to be used later.It always cures properly .

 

[William_H]

Epoxy Storagee

Here in warmer parts of the world. (anywhere might be warmer than UK right now from what I hear) epoxy is stored at low temperature to increase the shelf life. So yes it should be fine when warmed up. but don't try to get it to harden unless you can increase ambient temp.

Interesting that in aviation Hi Tech jobs like aircraft structure they use what is called PrePreg carbon.
Here carbon fibre is impregnated with mixed epoxy hardener and base to a precise ratio. The wet cloth is then shipped to the end user refrigerated. The end user puts the wet carbon cloth into a mold then heats it with pressure to make the epoxy go hard. The shipping time can be many months. The epoxy is fine provided it is kept refrigerated. (As far as the epoxy is concerned carbon is same as glass). Obviously if the refrigeration fails the cloth goes hard so recording thermometers are an essential part of the shipping.
olewill

 

[Bosun Higgs]

When I mix a batch and don't use it all I keep what's left in the freezer to be used later.It always cures properly .

Interesting. I've done that with polyester and indeed keep my resins in the freezer to SWMBO's irritation, but never tried it with epoxy.

 

[30boat]

Interesting. I've done that with polyester and indeed keep my resins in the freezer to SWMBO's irritation, but never tried it with epoxy.

I also do it with two pot paint.It smells and SWMBO is never amused.

 

[aquaplane]

I have heard of some folks not wanting the hassle of mixing epoxy so they get it premixed.

They do need to keep it at -40°C but it has a 12 month use by date.

On warming to room temp it needs using just like normal epoxy.

 

[rhumlady]

I have heard of some folks not wanting the hassle of mixing epoxy so they get it premixed.

They do need to keep it at -40°C but it has a 12 month use by date.

On warming to room temp it needs using just like normal epoxy.

So it would be quite at home out side the back door just now then Bob;-)

 

[aquaplane]

So it would be quite at home out side the back door just now then Bob;-)

Only if it's -40, celsius or farenheit, I forget which

 

[nathanlee]

Should I now consider it useless and junk it or is it usable yet unpredictable?

Nah. A bloke building a rather elegant 36ft junk rigger in a self built shed with no heating next to Kudu, just pops it in the microwave for a bit.