Using a desiccant in a powder cannister.

[Centaur 1]

I have several small desiccant capsules and I was thinking about putting them in the powder bottle. Is this a good idea, or will it do something bad to the powder? I know that we all take precautions like using static free containers that block light, but i wonder why nobody ever mentioned using a desiccant to keep the powder from absorbing moisture. I'm talking about those small can shaped ones that come in vitamin and drug bottles.

[Rocky Raab]

I wouldn't.

Powder adsorbs moisture; not much but some. That moisture is included in the charge weights tested by labs. If you remove moisture from the powder, a given volume of it will weigh "light" and you'll naturally add powder to bring it to the "right" weight. Except it isn't right any more.

[Centaur 1]

Thanks Rocky, I worry about the high humidity here in Florida, but I also suspected what you said about altering the moisture content of the powder. You almost never hear about an old powder not working due to age, so I'm probably creating a problem where one doesn't exist.

[Rocky Raab]

I agree. I lived there for nine years, and never had a problem. But I was adamant about leaving powder out for as short a time as possible. Load and get it back in the sealed can immediately.

The former lab chief at Speer now writes for Shooting Times, and he just recently told an anecdote about how they had fits with data until they began storing and loading in a temp and humidity controlled room. Now, OUR results aren't nearly as critical, and I would not say that such steps are required for every reloader - but it DOES point up the fact that environmental factors do influence reloading.

Congrats on your continuing string of Centaur successes, my friend!

[376Steyr]

Another thought, what if the plastic that dissicant capsules are made of is not compatible with powder? Be a shame to pour some powder and have a sticky, gooey mess plop out of the bottle.

[felix]

Very true about powder taking on moisture, and vice versa. Some of these plastic jugs allow moisture transfer, so metal cans are preferred. Even when casting. Moisture affects the mold between drops, and somehow acts like lube filling up the micro holes. Very pronounced with iron molds, so casting should be done during a condensing atmosphere. This is when dew is obviously coming down (casting outside), or during a humid feeling rain (casting inside). ... felix

[mtnman31]

When I lived in North Carolina (humid) I used dessicant bags in my powder storage box. Mind you, it was not inside the powder container itself but in the locker I keep my powder in. My powder storage locker is not air tight so I used the dessicant to keep moisture levels down. The desicant may not have been needed but it gave me peace of mind.

[Shiloh]

Ditto what Rocky said.

Powder absorbs a limited and finite amount of moisture. The solvents in it moderate the amount. I saw a post on this but can't find it in the search feature.

Keep your powder containers closed and you'll be fine. If the powder needed a desiccant, it would be there from the factory.

[swheeler]

I never have and wouldn't do it, if concerned put them in the cabinet with the containers but not inside them.

[Rocky Raab]

To be absolutely precise (and seemingly pedantic as well), powder ADsorbs moisture, but does not ABsorb it.

Adsorption is when moisture is collected on the surface, and absorption is when it is taken into the material. In the case of smokeless powder, the kernels are too dense and too impermeable to absorb. But the net result is much the same: moisture comes in and out of the air and is "collected" by the powder.

Blackpowder on the other hand does absorb moisture - like a sponge. It's the potassium nitrate that does it.

[Centaur 1]

Congrats on your continuing string of Centaur successes, my friend!

Thanks, I started with General dynamics back in the late 80's, and was laid off by Lockheed Martin in 2005 when the Titan program came to an end. The Centaur is an awesome vehicle. The version that we used on Titan was the largest, and it was derived from the Shuttle Centaur, which was cancelled after the Challenger accident. Not only could we lift huge payloads, we did it with more precision than any other launch vehicle.
I'm now retired due to a bad back, but after Titan I worked as a technician on Space Shuttle Atlantis. Today was a sad day at KSC, many of my good friends were let go due to the Shuttles being retired. By October over 2/3 of the workforce will be unemployed, approximately 10,000 people.

[madsenshooter]

Hormady's 3rd edition shows the difference between dry powder and powder at normal moisture content. An extreme example was a 60+ year old 50 caliber round my uncle, who was a B24 belly turret gunner, brought home from gunnery school. The round had sat live in my grandma's knick-knack cabinet all that time. The powder was bone dry and some had crumbled away to dust. The inside of the brass case was green with verdigris, it had apparently adsorbed all the moisture from the powder. I noticed a post by Mike Venturino showing some awesome pressures generated by WWII vintage ammo, maybe this is why.

Hey Felix, I was reading on some odd forum once about a fellow who water quenched his boolits by putting the mold, still containing the hot casting, into water. Maybe he got good boolits after that because of the mold's moisture content! I couldn't help but wonder what'd happen if there was still a drop in there when he next filled it. I'd think it'd have a tendency to spit the molten lead back out.

[Centaur 1]

Hey Felix, I was reading on some odd forum once about a fellow who water quenched his boolits by putting the mold, still containing the hot casting, into water. Maybe he got good boolits after that because of the mold's moisture content! I couldn't help but wonder what'd happen if there was still a drop in there when he next filled it. I'd think it'd have a tendency to spit the molten lead back out.

I couln't help but notice how you said,"some odd forum once". What really happened there, was that you caught a glimpse of Darwinism at work. Hopefully that mold quenching experiment happened before he was able to reproduce and father an offspring. :mrgreen:

[madsenshooter]

I'd never find it again, wasn't a regular casting forum. I was wondering all sorts of things. Like how does he get good bullets from a cool mold? Or wouldn't that maybe warp the mold? Maybe he had no idea what a good bullet looked like.

[EOD3]

Hey Felix, I was reading on some odd forum once about a fellow who water quenched his boolits by putting the mold, still containing the hot casting, into water. Maybe he got good boolits after that because of the mold's moisture content! I couldn't help but wonder what'd happen if there was still a drop in there when he next filled it. I'd think it'd have a tendency to spit the molten lead back out.

Over the years in EOD, I/we did some things most people would consider suicidal. The reason we lived through it was a reasonably complete understanding of the processes involved. I don't think I'd stay in the same room with someone that would intentionally do something like that.

[uscra112]

Back when the NRA technical branch actually had real engineers, they strongly advised against putting dessicant in with powder. Overly dry powder speeds up significantly, and would cause dangerous pressures, they said.

[Rocky Raab]

I'm no engineer (although I did play one on TV!) but that's not an unexpected result.

[ksJoe]

Regarding the solvent content...

I've read someone report his loads changed from the beginning of a bottle of powder to the end. The person was using a crono, and trying to keep things as consistent as possible. His conclusion was that by the time he finished the powder, some of the solvents had evaporated out, slightly changing the charge weights.

So he put new powder in an open dish and stirred it occasionally for a couple days. Then put it back in the original container, and saw more consistent results.

There was some controversy about the safety of that, but his position was that the powder ended up in that state anyway. He just getting it there to begin with. I forget which powder he was using, but IIRC, it had a strong solvent smell.

[Moonie]

This would be why some of us prefer volume measurement rather than strictly weighing all charges. The weight may change but the volume will not.