can annyone tell me the appox. life of aftcote and u40 epoxy. I have had it stored in my shop cabinet for about a year or so. temperture stays at about 65 to 70 degrees.

It will last longer than we will LOL!

Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

Hank,
This is a very good question, and depending on the product, can have some different answers.

I think that Mke is correct on the particular products that you address.

But, if you look at two part products directly, and or solvent based products, you will find some answers.

It seems that for two part products, like epoxy glue, epoxy finish, certain two part paints, the shelf life issue tends to come down to the hardner side of the product. The resin or paint base part of the product tends to be stable for a very long time. But the hardner side of the product tends to have a shelf life that may be measured in months or a short number of years.

For solvent based products, and or products that are temperature sensitive, it is dependent on the tightness of the container, whether the container has ever been opened, and what the particular solvent is that is in the product. A solvent based product will cure by the evaporation of the product. So, if the seal on a container has been broken, there is a chance that there may be some solvent loss over time. If the solvent evaporates, the product will tend to become useless. If it is an air cured product, any air intrusion will allow the product to cure in the container. There are some products that are sensitive to UV or light. and or temperature. So, depending on light and or temperature, these products may become nonusable more quickly as a function of either light and or temperature.

Bottom line-
If you have a product that is of some age, be sure to test the product on a test piece, before commiting a big build or expensive components to the use of an 'old" product that may or may not set up the way that you want it to set up.

Good luck

Roger

Can't speak for U-40, but the Aftcote will "chunk up" over time and it's the resin, not the hardner. The hardner stays fine but does go to a brown coloration. The resin gets white specks in it after some time of non use. Some of it can be corrected by heating the resin, and some of the chunks can never be brought back to liquid properly if left long enough. These chunks are SMALL but there like little white dust bunnies within the finish. Just something to look for.....

DR

There is no shelf life for either. They don't go bad and will continue to set and cure normally for years and years.

If the resin crystallizes, you can restore it to like new condition with the application of heat.

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thanks for the help guys. The part A looks good but part B looked darker in both brands. I did not know if it was my imagination or not. I am going to try some on a wrap and see what happens.

The darkness wont hurt a thing in the hardner, all brands do this.

DR

With one possible exception, all epoxy hardeners will darken over time (both in the bottle and on the rod) but this no way affects their ability to set and cure.

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[www.dow.com]

Those aren't the type epoxies we use in thread wrap finishing.

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