Old epoxy--somewhat OT (but it's an epoxy question)
 

I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and have
used the stuff from time to time on non-critical applications and it seems
to work okay.

But this task is different--a couple of chairs--and I don't want to skimp.
I have to use epoxy on this glue-up because it is slippy and has a long open
time.

Does anyone know for sure if I can use what I have or need to get some fresh
stuff?

Regards,
David Todtman

*** Remove NOSPAM to reply ***
"David Todtman" wrote in message
news:tZDne.1538955$Xk.284088@pd7tw3no...
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and have
used the stuff from time to time on non-critical applications and it seems
to work okay.

I'd like an answer on this one too - it's expensive stuff and I have about a
litre of it in a sealed tin which I'd hate to throw away, if it's usable.
For the record, I recently finished using a tube of Araldite (not a marine
product but an epoxy FWIR) which I've had for 30 years and it seemed to be
as good as the day it was made!
John.

System Three states that shelf life for their resin and hardener is
unlimited if stored in closed containers below 90 degrees Fahrenheit. Other
brands may differ.

As you know, if stored below 40 degr (?), it will crystallize. Warming it
in a pot of hot water or a closed car will return it to clarity.

Roger

http://home.earthlink.net/~derbyrm

"John Seager" wrote in message
...
*** Remove NOSPAM to reply ***
"David Todtman" wrote in message
news:tZDne.1538955$Xk.284088@pd7tw3no...
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and
have
used the stuff from time to time on non-critical applications and it
seems
to work okay.

I'd like an answer on this one too - it's expensive stuff and I have about
a
litre of it in a sealed tin which I'd hate to throw away, if it's usable.
For the record, I recently finished using a tube of Araldite (not a marine
product but an epoxy FWIR) which I've had for 30 years and it seemed to be
as good as the day it was made!
John.

I would prob use the resin... but would certainly get new hardener.
Advice from a man who REALLY KNOWS the chem of epoxies suggests that the
resin is very stable but the hardener can degrade quite drasticly .. This
is apparently applicable to 99% of epoxy products regardless of who/where it
was made.
"David Todtman" wrote in message
news:tZDne.1538955$Xk.284088@pd7tw3no...
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and have
used the stuff from time to time on non-critical applications and it seems
to work okay.

But this task is different--a couple of chairs--and I don't want to skimp.
I have to use epoxy on this glue-up because it is slippy and has a long
open time.

Does anyone know for sure if I can use what I have or need to get some
fresh stuff?

Regards,
David Todtman

Great news! I'll get new hardener.
Thanks to all,
David Todtman

"James" wrote in message
...
I would prob use the resin... but would certainly get new hardener.
Advice from a man who REALLY KNOWS the chem of epoxies suggests that the
resin is very stable but the hardener can degrade quite drasticly .. This
is apparently applicable to 99% of epoxy products regardless of who/where
it was made.
"David Todtman" wrote in message
news:tZDne.1538955$Xk.284088@pd7tw3no...
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and have
used the stuff from time to time on non-critical applications and it seems
to work okay.

But this task is different--a couple of chairs--and I don't want to
skimp. I have to use epoxy on this glue-up because it is slippy and has a
long open time.

Does anyone know for sure if I can use what I have or need to get some
fresh stuff?

Regards,
David Todtman

David,
The tech lines at West are always helpful. You migtht just ask them.

I have some 205, that is at least a decade old, that I got out the other
day (I only use it for small repairs that have to cure fast). It was
just fine, but the pump was trashed.

Matt Colie

David Todtman wrote:
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and have
used the stuff from time to time on non-critical applications and it seems
to work okay.

But this task is different--a couple of chairs--and I don't want to skimp.
I have to use epoxy on this glue-up because it is slippy and has a long open
time.

Does anyone know for sure if I can use what I have or need to get some fresh
stuff?

Regards,
David Todtman

James wrote:
I would prob use the resin... but would certainly get new hardener.
Advice from a man who REALLY KNOWS the chem of epoxies suggests that the
resin is very stable but the hardener can degrade quite drasticly .. This
is apparently applicable to 99% of epoxy products regardless of who/where it
was made.

I've been told exactly the opposite by another epoxy manufacturer. They
claim that the resin has a limited life (as evidenced by
crystallization), but their hardener last indefinitely.

"Matt Colie" wrote in message
...
David,
The tech lines at West are always helpful. You migtht just ask them.

I have some 205, that is at least a decade old, that I got out the other
day (I only use it for small repairs that have to cure fast). It was just
fine, but the pump was trashed.

Matt Colie

David Todtman wrote:
I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and
have used the stuff from time to time on non-critical applications and it
seems to work okay.

But this task is different--a couple of chairs--and I don't want to
skimp. I have to use epoxy on this glue-up because it is slippy and has a
long open time.

Does anyone know for sure if I can use what I have or need to get some
fresh stuff?

Regards,
David Todtman /////////////////////
Place the old resin in a deep container, get larger container with water ,
place resin container in the water, bring water to boil for a few minutes,
let cool, the resin will be as good as new.

On Sat, 04 Jun 2005 11:04:58 +0000, Brian Nystrom wrote:

James wrote:
I would prob use the resin... but would certainly get new hardener.
Advice from a man who REALLY KNOWS the chem of epoxies suggests that the
resin is very stable but the hardener can degrade quite drasticly .. This
is apparently applicable to 99% of epoxy products regardless of who/where it
was made.

I've been told exactly the opposite by another epoxy manufacturer. They
claim that the resin has a limited life (as evidenced by
crystallization), but their hardener last indefinitely.

Crystallization is totally reversible, and the original poster said he
knows how to handle it. You can verify this by reading information from
bulk epoxy suppliers such as Resolution Performance Products, who now
supply the Epon epoxies which used to be supplied by Shell.

Here is the URL for a product bulletin about EPON Resin 828, which I think
is one of the most popular epoxy resins ever. Many epoxies that small
end users such as us can buy are probably based on EPON 828.

http://www.resins.com/resins/am/pdf/RP3075.pdf

A selected excerpt:

"EPON Resin 828 is susceptible to crystallization upon prolonged storage
at normal ambient temperatures. It may be reconstituted by warming to
120-140 F for 4-24 hours depending on the mass involved."

HTH.

BTW, if you are interested in learning more highly technical information
about epoxies, the resins.com website is a good place to sniff around. And
of course, Paul Oman seems to be a good resource, too. ;-)

--Mac

"Matt Colie" wrote in message
...

David,
The tech lines at West are always helpful. You migtht just ask them.

I have some 205, that is at least a decade old, that I got out the other
day (I only use it for small repairs that have to cure fast). It was just
fine, but the pump was trashed.

Matt Colie

David Todtman wrote:

I have a glue up to do that requires epoxy. I have some old stuff (West
Syst.)--both resin and hardener--that was purchased way more than 5 years
ago. I know how to get rid of the crystallisation from the resin and
have used the stuff from time to time on non-critical applications and it
seems to work okay.

But this task is different--a couple of chairs--and I don't want to
skimp. I have to use epoxy on this glue-up because it is slippy and has a
long open time.

Does anyone know for sure if I can use what I have or need to get some
fresh stuff?

Regards,
David Todtman /////////////////////

Place the old resin in a deep container, get larger container with water ,
place resin container in the water, bring water to boil for a few minutes,
let cool, the resin will be as good as new.

yeah, I just the other day used some west system epoxy which must be
around 10 years old. It worked fine, but the hardener was a darker
color than I remember. Either it darkened over time, or I just don't
remember it correctly.

Julien