My S-I-L works in a shop where he does powder coating. He told me today that they had throw out a couple of cases of powder coating. The were from an order that was several years old and they no longer had that contract. The shop owner said to get rid of it as it was taking up storage space and they were not using it anymore. My question is does the powder coating material go bad sitting in a sealed container? He threw away more than I could use in two lifetimes...........

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USMC 69-93 Combat Pistol Inst.

My GUESS would be no, but I can't claim any expertise in the area.

I'd guess it was a special color and he has no other demand for it.
There are thousands of colors available and industrial powder coat is not that expensive.

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"I also cook."

With proper storage, it would never go bad. My two cents.
(worked with an old timer in the lab who once said, "chemicals don't know time")

I have told him to bring some home if he asks for it. Don't want him to get in trouble. If he can I will try some out and report back.

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USMC 69-93 Combat Pistol Inst.

My hoarder friend gave me some old baggies of powder and they worked fine.

Yes it can go bad and when depends on how it was stored.
Should be an expiration date on the cartons and description of how it should be stored. Might be fine ... might not be. Chemicals do react to the environment .. temp, etc.

It can't be any worse than the oxidation, light gray color on my old semi jacket, Speer 160 gr lead tipped bullets that I loaded back in the 80's.

I don't think that plastic can rust ?

Used some years past the "quality assured" date several times, and it was still fine. Only thing I know that bothers the powder is moisture.

Using up some stuff that I had in sub optimal storage.
Seems a little reluctant to cling.
Beyond that, it coats, sets and functions

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it just needs more voltage

I'm in the "Keep your powder (coat) dry" camp. I've had some for 4 or 5 years of unknown best by date. I had some in an unsealed container that didn't want to adhere but no other problems.

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Just Say No - To Social Media

Can Powder Coatings be Used Past the Expiration Date? | 2019-08-26 | PCI Magazine


Can Powder Coatings be Used Past the Expiration Date? | 2019-08-26 | PCI Magazine


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There are many more.

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Still Running Against the Wind

I’m using stuff that is at least 5 years old and probably closer to 10 without issue. If using shake and bake method there are powders that don’t work very well to begin with. So your results may vary. I’d test it out and if it adheres and cures correctly I’d assume it should work OK.

Next question......Can fresh powder coating be applied over powder coating that did not adhere well?

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USMC 69-93 Combat Pistol Inst.

Exactly what kind of powder was in those baggies...

Put new powder coating on powder coating that is non-adherent and you still have a non-adherent coating

Guess I will have to try an experiment.....

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USMC 69-93 Combat Pistol Inst.

Dodge/Chrysler tried that in the late 80's early 90's.

If it was stored without sufficient exposure to moisture or silicone (silicone laced waxes and glossifiers will drive a paint n body shop NUTS - Some products are outright banned from the premesis)? Then you're fine.
If they're not sealed, moisture could lead to clumping. Silicone exposure will cause adhesion problems.

Just tried putting Eastlake Red over some 10MM bullets that were poorly powder coated with some old Harbor Freight Red powder coating.

Shake & Baked as normal. Power adhered as it should before baking. When finished looked great. Sized the bullets and none of the new powder coating came off. Works good!

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USMC 69-93 Combat Pistol Inst.