Strange Powder Storage Situation

My basement is at 35-40%, depending on the weather. The dehumidifier also helps warm up the air when the air conditioner is running on those hot days.
 
The problem would be, HOW does the moisture get into an IMPERVIOUS PLASTIC CONTAINER?

maybe it's the nitrocellulose decomposing very gradually and creating some kind of chemical compound inside the can. if you can detect it with your nose there are aerosols floating around.
 
maybe it's the nitrocellulose decomposing very gradually and creating some kind of chemical compound inside the can. if you can detect it with your nose there are aerosols floating around.

An aerosol is a cloud of teeny droplets of liquid. I think you mean VOCs (volatile organic compounds) which are low weight molecules that produce a vapour.
 
Ganderite told me many years ago not to put desiccant inside your powder containers, it can mess with its natural moisture content.
I'm going to hazard a guess that that desiccant is drawing moisture from the outside in, causing the corrosion.
 
One of those containers has powder that is beginning to break down, releasing acidic vapors.
If it still looks good, it has not progressed to the "visible" stage yet, but it will.

I dumped 21 lbs of OEM 4350 [N160] that did that. Also had 3 lbs of CF 7900 [4831 clone]
The latter had gassed off it's fumes when I discovered it, and the powder was a solid "block"
of powder grains which would not even burn when I tossed it in the firepit.

OTOH, I have some powders here that are decades old, and work just like they did when new.
One other caution.....there have been cases of spontaneous combustion of powders that are
deteriorating. Be safe! Dave.
 
Ganderite told me many years ago not to put desiccant inside your powder containers, it can mess with its natural moisture content.
I'm going to hazard a guess that that desiccant is drawing moisture from the outside in, causing the corrosion.

I didn't take it as the desiccant was "in" the can. I took it to mean it was in the storage cupboard.

If this is the case,???????
 
One of those containers has powder that is beginning to break down, releasing acidic vapors.
If it still looks good, it has not progressed to the "visible" stage yet, but it will.

I dumped 21 lbs of OEM 4350 [N160] that did that. Also had 3 lbs of CF 7900 [4831 clone]
The latter had gassed off it's fumes when I discovered it, and the powder was a solid "block"
of powder grains which would not even burn when I tossed it in the firepit.

OTOH, I have some powders here that are decades old, and work just like they did when new.
One other caution.....there have been cases of spontaneous combustion of powders that are
deteriorating. Be safe! Dave.

I had exactly that same thing happen with my 47N (OEM4350) aka N160. Mine had moist clumps. The #44 all went rusty and the smell was extremely bad

The #44 powder was being used in a lovely Winchester Model 70 FWT, chambered for the 257 Roberts.

I took it on a Coyote hunt and it wasn't shooting well at all. I had to go to work that night and put it in the safe.

I came back to the rifle four days later, after the shift cycle.

The bore was filled with rusticles.

I tried to clean it and it was unsavable. The bore looked like someone had taken a ball-peen hammer to it.

That's when I went to the magazine and checked the powder, which had deteriorated.

Some of it, including the container I had been using looked fine, some of it was, as you stated, a solid block, and the laminated paper containers were stained. The metal caps were all rusty inside, even on the powder that looked ok.
 
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Thanks for sharing, very interesting.

I never had that issue before. However it reminds me a situation I came across a few times in a previous life: crystalized nitro on dy-na-mi-te paper and wood packaging from long inadequate storage. The stuff does seep out of the mix. It was disposed of (burned) at a disposal range.

Personally, I would treat the sight of lid corrosion like a "check engine" sign. For whatever reason it happens, there is an air/gas exchange at the metallic container closure and I perceive it as a sign (if not the cause) of powder degradation. With presence of other signs like strong foul smell or agglomeration (clumps), I would discard the powder. We should all take good note that a plastic lid (instead of metal) will likely not exhibit corrosion (no "check engine" sign) and powder degradation still may occur if container closure, storage and/or ambient conditions allow it.

How to prevent that is the next question. As mentioned earlier in this thread, safe/adequate storage is a must (ventilated storage container/cabinet in a dry cool place) . Temperature change will allow air/gas to migrate to/from the container so a proper seal at the closure definitely help to minimize or stop the possibility of it. After use, I always make sure the container lip and lid seal (waxed paper?) is free of powder grains and the contact surfaces are even and smooth. YMMV
 
It was in the bin the powder was stored, not the individual cans themselves.

Nothing wrong with that.

In a previous post, I described a laminated paper container I have that is at least 75 years old.

When I purchased that container, I bought fifty drums that were 25# and 15 drums that were 50#. All of it, except for two 25# drums went to a half dozen gunshops in BC and Alberta.

When I went to Bruce Hogdon's storage facility, there were several open sided "hay shed" type structures covering concrete pads, stacked with large wooden crates, lined with tarred white paper full of these drums.

Some of it had been stored in this manner for close to two decades, after he bought the "surplus" powder from government auctions and sales.

The lot I bought was the oldest he had in storage and he was quite happy to get it gone, so he sold it to me at a price I couldn't turn down. That's where I first met Tom Higginson, of AMMO MART. Tom and Bruce Hogdon had known each other for years.

Tom was kind enough to walk me through the process of getting the legal paperwork for the transfer and allowed me to tag onto one of his contracts.

He was being very generous but it also helped him out as well. The larger the quantities purchased, the cheaper the products.

Back on topic. The conditions the powders were stored under would not be considered ideal, other than they never froze but in the summer, temps got quite high and I believe the only purpose for the "hay sheds" was to keep the direct sunlight and rain off the crates.

Humidity was high.

The only real protection these powders had was the "tarred back, heavy white paper" wrapping and lining on the drums and in the crates.

I still have some 3031 from those days as well and it's fine.

Powder will eventually break down. A lot of this has to do with its chemical composition and the burn rate coatings.

Ganderite could give us way more detail on this and why some powders break down, while other's seem to go on forever.

Last fall, I was given an old powder horn full of FFG black poweder. Yes, I know it's much different from smokeless.

The last time the powder had been used was 1980.

I was curious as to it's usefulness after 45 years, so I loaded a 65 grain charge by volume into my Lyman 50cal Plain's Rifle, which is just slightly older than the powder. I loaded and shot ten rounds at a 50 yard target, off the bench. Nice tight group after the first fouler.

I shot another ten with a recent lot of powder, with the same balls and charge. You would be able to tell which shots were from which lots.
 
Not how, when.

When you can get liquid water or gaseous water, not under pressure, to penetrate and impervious plastic jug.

Can air contain water vapour or droplets of water? Can gunpowder hydrate itself (hygroscopic)? If so, can air enter through the lid of the container?
 
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