Does humidity affect components? If so, how?

ArkieVol

New member
I am a new reloader and set up my stuff in a stand alone 10'x12' concrete block (former) catch-all storage/shop building. Cleaned it all out and have a nice place to reload but there is no climate control. I have electricity; lights, outlets, etc., box fan for summer and plug-in electric heater. I live in Arkansas and sometimes it gets pretty humid...as it did today.

Started to load some ammo but it was so humid after a heavy rain that I began to wonder if all that humidity would have an adverse effect on any of the components; powder, cases, primers. I know the instructions say to store powder and primers in a cool and dry place but wondered if reloading in warm and humid conditions could cause any problems.

Any comments, advice or suggestions?

Thanks
 

PBKing

New member
I know the instructions say to store powder and primers in a cool and dry place but wondered if reloading in warm and humid conditions could cause any problems.

Instructions...Good
Humidity......Bad

The problems that humidity can cause are too numerous to mention.
 

wpsdlrg

New member
Humidity is a problem. You'd be better off storing your powder and primers indoors. For brass and bullets, etc. it doesn't matter, nothwithstanding possible corrosion (depending on how the items are stored....and how much the temperature and humidity change in your shop building). You can eliminate most or all of the potential effects to your brass, etc, by simply storing it in resealable plastic bags, with the air squeezed out.....and placing the bags in an insulated box (even a cooler will do)....that will minimise temp. changes. However, such precautions as that may well be overkill - unless you live in a tropical rainforest....or New Orleans.
 
Humidity can stop the primers and powder from working over time. Corrosion is another issue. Sweating condensation is another. Lots of potential trouble there.

If the building is on a slab rather than having a dirt floor, you can use Thompson's water seal on it and the walls to form a vapor barrier that will help. If you have a door and windows with weather seals, then a dehumidifier could be run inside. Just drill a hole in the concrete block at the floor level for a length of garden hose that lets the dehumidifier drain continuously to the outside. A window air conditioning unit is another possibility if you run it a couple of hours before a loading session. If you don't have windows, a circular saw with a diamond blade will put one in the block for you.
 

snuffy

New member
Humidity......Bad

The problems that humidity can cause are too numerous to mention.

Humidity can stop the primers and powder from working over time. Corrosion is another issue. Sweating condensation is another. Lots of potential trouble there.

I disagree. Primers have a sealant over the explosive pellet that wards off simple humidity. Powder comes in sealed cans, that are re-seal-able,(it's the cap). Opening a can of powder to be used on a humid day does nothing to how how it works. This has been proven time and a gain in controlled tests. It has no effect on the combustion of the powder/primers.

I loaded in a basement that frequently had standing water in it for 15 years. I had to constantly battle rust on dies and loaders. BUT it did nothing to the loads I made in those conditions. Brass can tarnish under those conditions, but it will still work, just not look good.
 

PBKing

New member
I loaded in a basement that frequently had standing water in it for 15 years.

You just gotta love a guy like that.

Right On

I am sticking with Humidity ....BAD
 
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Farmland

New member
Living in an old farm house with a spring flowing into the basement all I have to do is add minnows and I have a new business.:D

Now I'm not going to say it isn't a good idea to keep the primers and powder in an environmentally controlled room as much as possible. However I have found that both are a lot more tolerable than we think. I do like to store my primers boxes in a zip lock bag because my reloading room is subject to wide changes in humidity. I even store the powder containers in a zip lock bag after breaking the seal.

I will be honest I don't know if this helps but so far it hasn't hurt.
 

Edward429451

Moderator
I noticed over time that when I left powder in the measure overnight, when I returned and rechecked zero...almost always the weight would read a little higher by a couple tenths. I concluded overtime that it would absorb humidity but not enough to deactivate it. I clean up and restore religiously now. And keep a humidity meter in the reloading room
 

BigJimP

New member
You guys make me feel bad ..... I load in a comfortable indoor shop, no humidity, no plague, no poisonous critters lurking - its even well lit and well ventilated ..... I guess I'm just a wimp...
 

gtullar

New member
Dry Is Good

I reload in my Arizona garage, gets hot in the summer but humidity is NEVER an issue. Powder function in high humidity is not the issue but metering could be. You've gotta think moisture would make the powder flakes want to "stick" together causing inconsistent loads. Then again, maybe not.. :confused:
 
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