Optimum room humidity?

[Orygun]

Have been trying to find out what the optimum humidity would be for a basement reloading room that also stores powder, primers, gun safes, steel boolit molds, etc.
I really haven’t had a noticeable problem and I don’t live in a humid climate, but have recently acquired a dehumidifier and it seems to suck a lot of moisture out of the air. I don’t want it TOO dry in the room. Any ideas?

[lurch]

Not sure if there is going to be a definitive answer on this, but I'd SWAG a number in the 50% to 60% range.

[JIMinPHX]

For storing guns, molds, etc., the optimum humidity is zero. For handling powders & primers, you probably want a little more than that to cut down on the static electricity. I don't know how much is enough.

[Orygun]

I don't think that 0% would be good as it would suck all of the moisture out of wood stocks, etc. I think about 40%-50% is okay for living spaces and is probably fine for reloading rooms, but I don't know.....and would like to.

[Bob Krack]

20% minimum if wood is to be stored there also. 40-50% would prolly be a good compromise.

Bob

[mpmarty]

Firearms are stored in large Browning safe with about ten pounds of silica gel which is dehumidified in the oven once a month. Hygrometer in safe stays between 5 and 10 percent humidity.

Powder is stored in 6' X 4' X 4' steel rolling box with hinged top lid that would blow open in case of a disaster.

Primers are stored in refrigerator in my reloading area along with my welding rod.

Reloading tools are stored in wooden cabinet in reloading area. I haven't found any rust on any of them in twenty years or more.

Boolit molds and such are stored a quarter of a mile down my driveway at my 96 X 24 shop in drawers that used to be in a kitchen. The molds are stored with the last cast in them with the sprue cut and the outside sprayed with CLP then wrapped in waxed paper.

Here in the western Oregon mountains the humidity ranges around 40% to 60%.

[Jim]

I spent 32 years in mechanical contracting which, for the most part, is about treating, conditioning and maintaining air. It is possible to achieve 0% humidity, but the cost of the structure and equipment would be astronomical.

[Orygun]

And we might as well throw temperature into the mix. If one should "keep your powder cool and dry"....well, how cool, how dry?

[AZ-Stew]

We gots plenty o' "dry" in Arizona. In May and June we can count on low teens or high zeros (6-15%) humidity. As the summer wears on, the humidity increases as the sumer monsoon storms move in. The rest of the year (Oct. - April) it averages in the 30-60% range. It's one of the reasons I like it here.

I control temperature in my shop so it never gets above 83F. Low is as the winter weather takes it, usually above 50F, as my shop is well insulated. Primers are kept in the refrigerator, which is set at 40F. About half my powder is in there, too. The humidity and temperature in the 'fridge are ideal for powder and primer storage, not because of the numerical value of the temperature, but because the temp. is consistent. I just wish I had enough room for all my powder and loaded ammo.

I really wish I could recall the temperature limits we had aboard ship for ammo. I do remember that our guided missiles had a low limit of about 32F. Below that the 1,500lb solid fuel rocket motor was suceptible to cracking and delamination from its casing. Firing one with such defects would remove the upper parts of the launcher and numerous parts of the ships' superstructure, inside of which was the launcher control room where I sat during missile firings. I tried to prevent this situation.

As far as small arms ammo goes, I'd guess that storage limits between 20F and 90F would be adequate. My carry gun in my truck is exposed to 140F on a regular basis in the summer. My remedy for this poor storage is to replace the ammo after a couple of summers. That said, when it comes time for replacement and the old ammo is fired, none has ever failed to fire.

Regards,

Stew

[mooman76]

I'd say 25-50% range would be good but that's an educated guess. I obviously don't have a issue with humidity being too high here. Heat is a bad factor not cool. Cool is good for storage of powder primmer and ammo. The Military usually store theirs in under ground bunkers.

[44man]

My basement is about 60* in the winter and 70 to 75 in the summer. I keep humidity from 45 to 50%. No problems of any kind.
Now the strange thing is I pre cut wood, stack and sticker it in the basement for a month and I can make furniture that does not shrink or warp. If I take the wood out of the barn even though it has been there years, it will shrink like crazy. Even rifle stock wood turns out perfect if just dried in my basement.
My molds are just stuck in a drawer, nothing on them but Rapine mold prep and none rust.

[Bass Ackward]

I'm sort of against trying to control humidity levels unless it is truly for LONG term storage. Long term defined as 3 years or more.

You get used to humidity levels as they are. Humidity establishes .... routines or standards for everything that you mention and you simply adhere to them and you get no surprises.

But if you do try to control it, you get a false sense of security that these routines can be stretched beyond what they can. Starts the learning curve all over again. Chances are you will be uncomfortable and you will spend as much time monitoring to establish new intervals and procedures as you did doing them. Assuming that you don't have equipment failure that has to be monitored now as well.

In the end, you will eventually go too far and regret it. Just hope it wasn't something too highly valued.

[redneckdan]

I'm not quite so lucky. Here in Michigan the humidity gets near 90-100% in the summer. Anything left out in the basement without a coating of oil has a nice coat of rust in the morning. Everything gets sprayed with rem-oil. Molds that are stored long term I close the mold, wrap with twist of wire and drop into a .50 cal can filled with mobil 15w50....otherwise I have to go through everything about twice a month an recoat with rem-oil.

[Junior1942]

Like AZ-Stew, all my ammo, primers and powder are stored in an operating refrigerator--a frost free refrigerator. I store most of my powder in the upper, freezer section mainly because it fits. The key to success is not opening a container the same day you plan to use the contents. Let it warm slowly to room temperature or moisture will condense. Here in north Louisiana 80%+ humidity is the norm--if it ain't raining it's about to rain. An operating frost free refrigerator keeps everything at a constant low temp and low humidity.

[pdawg_shooter]

I keep mine at 45 to 50% and have had no problems in the last 35 years.

[Orygun]

I keep mine at 45 to 50% and have had no problems in the last 35 years.

And how do you do that pdawg?

Bass Ackward just may be correct and I'm over thinking and trying to fix a problem that doesn't really exist....but I sort of enjoy doing that sometimes. ;)

This all started with putting a desiccant canister in my safe and discovering that it needed to be re-charged too often. Hmmmm, where's the moisture coming from? Oh yeah, the door isn't really sealed, duh! So I installed weather stripping around the door frame, put up a Dri-Z-Air and got a small dehumidifier for the room.

Amazed at how much moisture these units filtered out, I started wondering about the loading components and molds, etc. so I got a large dehumidifier. (Yard sales are great!) :)
Now this large unit produced about a half gallon of water in 4 or 5 hours, but it also left the room a little too warm so I moved it out to the main room.

It continues to filter about a gallon in 4 to 5 hours set on a 40% humidity level. Again this is a basement......and an old one at that. Bear in mind that the washer and drier and air conditioning unit are all there too, so they are bound to create moisture/humidity much more that what we get upstairs.

So now I'm going to pick up a couple of inexpensive hygrometers and place one in the main area and one in the loading room just to see what kind of humidity there is and if I can reduce/maintain it to a reasonable level, whatever that is. I'm going to shoot for the 40%-50% humidity and the temps are usually very close to upstairs most all of the time.

This is what happens when you have too much time on your hands. ;)

[captaint]

It's relatively humid here in Pa. 70 - 90% is no big deal. The gun safes have a Goldenrod "hot stick" in them, plugged in at all times. In one safe I have a hygrometer "humidity guage" and it stays around 70% always. No problems. Enjoy, Mike

[snaggdit]

I worked in the computer industry for a while. When working on sensitive electronic circuit boards we had to wear anti-static wrist straps since a spark too small to feel can still ruin electrical equipment. In our server rooms and wiring closets we shot for 50% humidity. I did a quick search and found this site.
http://www.kirinoikeuchi.co.jp/eng/technical03.html
Seems that 55% might be optimum for our wood stocks to not dry out and powder to not get staticy. I don't know if that is low enough to avoid rust forming on molds, though. As others stated, applying some type of oil during storage would help with this.

[Shiloh]

I keep mine at 45 to 50% and have had no problems in the last 35 years.

That sounds reasonable to me. Too dry and you get static charges. It will shrink and crack wood over time. Powders and ammo like cool, dry, dark. It'll last forever. Well a LOONNGG time anyway.

Shiloh

[Jim]

I have a hummidity meter:D and a thermometer in my shop. I keep the air system set to achieve 60/60. No rust on the "hardware" and no mildew on the walls.

[c3d4b2]

I may not remember correctly...

I believe that with humidity above 50% (or is it 60%) mono layers of water will form on the surface of objects.

[snuffy]

Much to do about nothing of importance. In other words, I don't worry about it, I do nothing to control humidity. Except in the Wisconsin winters, it gets real dry in the house, I run a humidifier to keep wood furniture from falling apart.

Powder in it's original containers is safe from humidity, even if left open, it is not hygroscopic,(doesn't pull water from the air).

Primers are sealed against most anything except strong solvents. It has been shown time and again, it's nearly impossible to kill a primer, with certainty. I was warned when I started loading NOT to touch primers with my bare hands, the oil on my fingers would most certainly kill the primer! So I didn't! I think back on how silly that was now.

My iron molds don't rust if left as-cast for several months. If I know they'll not be used for a long time, I coat them with a spray oil protectant called super-tech. It's a itch-bay to get off-out of the cavities, but they don't rust. I do get rust on the lee mold handles, so unprotected steel would rust. Can't explain why my dies don't rust, must be the steel has some chrome in it?