Can Epoxy Resin go bad?

R

Rustystud

New member
I was bedding several rifles in my shop this weekend. I finished up the last of a gallon of fiberglass resin. I thought there was another quart on the shelf in my shop so I went and retrieved it. It was Sunday and I found a quart of resin that was brand new and unopened. It was a different brand than I have been using. I mixed up a batch and added the hardner. The trouble is it never started hardening. After 24 hours it still has not hardened.

One of two scenarios has taken place. The resin and hardner are not compatible or the resin has gone bad over the years on my shelf.

Has anybody else had this happen?

Nat Lambeth
 
Nat
Most epoxys have a limited shelf life, even unopened. Different brands of resin and hardener are usually not compatible and some use different mix ratios . One thing that is frequently overlooked is the effect of moisture on epoxy hardening. High humidity is not a friend to epoxy and can keep it from hardening.
Don
 
I just finished cleaning up two messes.

This was a real mess. A quarter roll of paper towels, approximately 100 Q tips, about a 1/4 cup of acetone, two hours and a pair of nitrile gloves. Now forgetting the brain cells I could not afford to lose. I guess I will have to go by West Marine today.

Hope no one else has this experience.

Nat Lambeth
 
A few months back I was doing something ??? [ creating a 20moa base I think ] with Devon 10110 and it never hardened. This was a small job so I cleaned up and tried again but taking more care with the mixing ratio and it worked correctly this time. When mixing up small quantities it is easier to get the ratio's out of whack.

What Don said is very true. For the amount of potential pita it is not worth trying to use the stuff past it's date and definitely don't mix different manufacturer's resin and hardener. Also, good ventilation. Everything you used for this job [ and clean up ] is bad for you and you can get to the point where even a small exposure to it will give you severe headaches / reactions .
 
Cleaning up after nonsetting 'glass is an evil job. I learned the hard way to put the purchase date on the stuff and toss it after 3 years.It just ain't worth the risk of a huge mess to save a couple of bucks.
 
Probably you had a hardener that was not compatible. If you tell me exactly what brand names and hardeners I may be able to tell you. "Fiberglass Resin" is usually considered polyester resin which you don't use for bedding. You have to be very specific about terminology because there are many 1000's of products out there. Epoxy is good for many years if stored properly and if not it can often still be made good again.
 
What Ian wrote!

And further...
You should try West System materials. Not the same as West Marine, they just happen to share a name, although West Marine may sell West System epoxies.

http://www.westsystem.com/ss/

Outstanding products for working with wood.
And it lasts for years and years.
 
West Marine sells West Systems products

West marine must sell 100 different fiberglass and expoxy products including West Products, Marine Tex, and MAS fiberglass products.

Stopped their this evening and got just what I needed. It is setting up as I type.

Nat Lambeth
 
Can the shelf life of 2 part expoxies be extended by refrigeration?

I was surprised and greatfull to find out on this messageboard that the shelf life of super glues are extended by refrigeration..............Don
 
It can be extended but you may find that some components crystylise out of the resin over time. You must warm the resin up and stir it back in. Once this is done it will be good again. We buy resin by the drum but often use it by the ounce. We look in the drum for crystallisation and then still put a drum heater on it for a couple of days and mix well before we tap off the entire drum into gallon jugs for easier handling.
 
Buying by the gallon and using by the ounce..

Last Friday I went to West Marine to buy a quart of Polyester Resin (fiberglass) and they only had resin in the gallon cans. The good news was it was on sale. Basically I got two quarts free.

When I got home I wanted to not make a mess and looked around to see what I had that could be used to get measured amounts from the gallon can without making a mess. Last fall I bought a couple turkey injectors to deep fry turkeys. There were several of these large syringes in my drawer. I said what have I got to loose. The turkey injecting syringe was marked 1/2 and 1 oz. The needle was made with two holes on each side. I carefully cut the end off the needle so it would just draw from the end. I opened the gallon can of fiberglass and drew my fiberflass resin into the large syringe measuring 1 oz. It worked beautifully. I cleaned up afterward with acetone. Just thought I would pass it along.

Nat Lambeth
 
Caution!!!

Do your epoxy basting before Mama comes home or you will be the roasted turkey!!! :D:D:D:D

overbore
 
Good thing about epoxy is that as well as being much stronger it doesn't stink of styrene as polyester does! To the next block!
 
Rustystud said:
I cleaned up afterward with acetone. Just thought I would pass it along.

Nat Lambeth
Click to expand...

Try vinegar with the epoxy cleanup, see what'cha think. Some types clean up well with vinegar.

If yer picky get the non-stinky kind :)

I weigh my epoxy mixes on my scale and mix in little plastic cups and plastic shotglasses, cheap and messless.

I do use a variety of syringes for injecting mix, like around pillars.

al
 
Don said:
Can the shelf life of 2 part expoxies be extended by refrigeration?

I was surprised and greatfull to find out on this messageboard that the shelf life of super glues are extended by refrigeration..............Don
Click to expand...

the original 'superglue' was manufactured by Kodak for NASA back in the early 70's. I worked in a camera store that sold it to the professional community.

we had to store it in a refrigerator (same one we used for film). Kodak's instructions were that it had to be kept at around 40 degrees F prior to use.
 
Devcon F has an expiration date on the box, only a few years. JB Industroweld is good for 20 years according to an email answer I got from them some time ago..
 
AMMASHOOTA said:
the original 'superglue' was manufactured by Kodak for NASA back in the early 70's. I worked in a camera store that sold it to the professional community.

we had to store it in a refrigerator (same one we used for film). Kodak's instructions were that it had to be kept at around 40 degrees F prior to use.
Click to expand...
That was Eastman's 910 adhesive. The patent was sold to Locktite about 20 years ago. It was discovered at the Tennessee Eastman Research Labs during a search for a new aircraft canopy material. They sent out samples to many potential customers and many customers stuck themselves to their phone. End of samples to potential customers. It is still available as a Locktite product but it doesn't have a good property as a filler for bedding but it has been used as a quick stick-back for an unglued action. Just ask Wilbur Harris and Studds McKee.
 
I've found that it's the epoxy hardner that goes bad with age rather than the resin. If it smells strongly of an amonia smell and has turned darker there's a good chance it won't harden. I've got epoxy paint in small cans that is 25 years old or more and just stored at room temperature and it still works as it did new but hardner more than 5-6 years old sometimes won't work. Seems to be true with the West system hardner also.
 
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This week I have some Acraglass Gel that took 2 days to harden.

In the past, all my problems have been from storing Devcon and Acraglass in the shop, and then mixing on a cold morning.

I now store all epoxy in the house, so it will be warm at the time of mixing.

Two weeks ago we made an all time high temp of over 100 degrees, and I thought I could store in the shop. Then this week we had some 57 degree morning temperatures.

I almost got caught again.

What does it all mean?
If the epoxy is cool when it is mixed, it will never harden at any temp.

http://groups.google.com/group/rec....thread/thread/b9690056cd1664b6/2ff40b2cba3907
 
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Build a wooden box, insulated with 1" of foam and wire up two 40w bulbs to an electric heat thermostat. Set the temp and the epoxy will always be at the right temp. The reason for two bulbs is that when one burns out it will still be the right temp unless of course they both burn out at the same time. You may or may not want to store the hardener in it as well. For Marine Tex for example I only heat the resin as the hardener is only 16% by weight.
 
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