Home Forums Hunting & Shooting Gunsmithing Acraglas Change?

In occasional batches of Acraglas I have noticed that the resin portion will get a bit cloudy, and thicker, especially toward the bottom of the container.

I am extremely careful never to let anything contaminate the two components.

Does anybody have an idea what might cause this? Does it affect the properties of the epoxy?

As expensive as epoxies are becoming, I'd hate to ruin and have to discard any.

Paul

I have had this happen as well. I don't know why. Left long enough, it almost looks like sugared honey. Shelf life used to be almost unlimited. Someone said a buzz with the microwave will fix it but I've been afraid to try. GD

I just used some that sorta looked like what both of you described. Other than the odd appearance at first, it worked fine.

Microwave can get it too hot and ruin the epoxy, use a water bath to prevent that.

Heat generated during mixing and then curing will break down the granules in the epoxy, but they may not get mixed much.
art

The only thing I can think of that might cause that is the resin starts polymerizing after the jar has been opened and exposed to air and moisture. I can't see how that would do a bedding job any good.
I've not had that happen with acraglass, but I have had it happen with Devcon that comes in the large bottles after it's been opened, and then the remaining amount in the bottle sits for a long time.

Thanks for the responses. I should add that this particular batch of Acraglas is only about three months old. I don't know how long it had been on the shelf, but I bought it at Sportsmans Warehouse, so I'd guess their turnover is pretty good.

I recently bought some Acraglas Gel that my gunsmith had ordered directly from Brownell's. I don't have much experience with the gel, but this batch was full of lumps.

'tis a mystery.

Paul

DMB

In the larger bottles of liquids such as glues/oils/stains, etc when you've used what you need, drop in some glass marbles to displace the air in the botte then seal, just be careful you don't let any marbles out when you pour again.

that'll keep the air out and not ruin whatever is in the container.

I know nothing about the chemistry involved, I'll defer to Sitka Deer about that, but I know that epoxies harden internally by a chemical process after mixing the resin and hardener. Solvent based products like most finishes dry from the outside in, when the solvents evaporate. At least that's how I understand it.

The question is, does exposure to air affect two-part epoxies in their containers? Could be, but I doubt they are as sensitive as normal finishes, so I doubt the marbles-in-the-jar would be of much help.

I'm waiting to be educated.

Paul

are not the components of the epozies dissolved in their own solvents/carriers to keep them liquid before mixing?

Well, the hardeners sure have a strong smell, some more than others.

Paul

I've routinely left two-part epoxies standing in pump-dispenser cans for months at a time with no adverse results other than some discoloration. Didn't matter how much air was in the cans. These were West System products, not Brownells, but I don't think there would be any significant differences in stability between the brands. My recent (last three months) buys of Brownells Acra Gel have been consistent throughout, no lumps, and no deterioration while sitting in their closed containers between uses during that period.

Epoxy lasts virtually forever. Warming it gently to dissolve the lumps will not cause any issues as long as you allow it to cool thoroughly before mixing.

No need for the marbles, either...