Purging air in ammo box

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bersaguy

bersaguy

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Has anyone tried purging the air out of an ammo can for long term storage? I have some silica packs and vci emitters, but I also have a can of non flammable computer duster. It contains tetrafloroethane which is heavier than air. I've heard of guys using nitrogen or argon, like shielding gas for welding. The duster is just more available for me.
Any thoughts?
BTW...I realize this is way overkill...but you know...anything worth doing, is worth overdoing.
 
I figured as much. Though, I did think about the valve stem idea. I think it would be better to introduce a slight positive pressure in the can with dry air. I think trying to evacuate enough air from an ammo can to reduce the oxygen would crush it like a soda can. I've seen crazy things happen to seemingly strong objects under high vacuum
 
Moisture in the oxygen bearing air is what causes brass to tarnish and from there to go on to corrode.

Based on my own experience (posted elsewhere on this forum) with brass cases stored in various configurations at the time I was stricken with the sudden onset of a neurological condition that left it sit for 20 years, cases stored in plastic boxes with individual compartments that are then stored in a sealed container from which moisture has been removed should be good. Silica dessicant bags are available for a few pennies each when bought in quantities and are effective at removing mositure from sealed containers.

Even stored in a sealed container with a dessicant bag, the cases will tarnish over the course of a decade or so, but my experience is that in these conditions the tarnish will not proceed to damaging corrosion even over the course of two decades.
 
When I was a teenager, the owner of the local welding shop showed me how he created an inert environemnt in gas tanks so that he would weld them. He had a small Briggs & Stratton engine and had a long tube running from its muffler. He would start it, put the tube over the tank's inlet, wait a few seconds until the tank was full of carbon monoxide and then start welding. I don't know if it would be effective to "inert" an ammunition can using this method, but maybe someone who still does their own lawn work would like to give it a try.
 
bersaguy said:
Has anyone tried purging the air out of an ammo can for long term storage? I have some silica packs and vci emitters, but I also have a can of non flammable computer duster. It contains tetrafloroethane which is heavier than air. I've heard of guys using nitrogen or argon, like shielding gas for welding. The duster is just more available for me.
Any thoughts?
BTW...I realize this is way overkill...but you know...anything worth doing, is worth overdoing.
Click to expand...

IMO you're already over-thinking/doing this if you're using VCI emitters in the cans.
 
I knew the idea was a little over the top. I haven't put the vci emitters in with the ammo...yet. right now I've been loading up cans and tossing in a silica gel pack. I plan on cleaning up the reloading equipment and packing that away in a mortar box with a vci emitter and desiccant. It gets too hot in the summer to work in the garage for any length of time in the summer here, and unfortunately we don't have basements in Florida.
 
I'm sure you could find one way valves that could be installed in the can and then throw in a chunk of dry ice and it will purge the oxygen.
Could probably just leave the lid cracked a bit and latch it down after the ice gased off.
 
So I live on the coast nice and cool. I go shooting about 35 miles away 30 or so degrees warmer when I get home can barley open the ammo cans vacuum sealed tight as a drum.
 
Just wondering,
Would a long term vaccum on an ammo can pull the air out of the cartridges?
And if so, what effect would it have on the cartridge when it was fired? Isnt the oxygen within the cartridge case needed for combustion?
I honestly don't know and am asking?
Thanks, catpop
 
Catpop said:
Just wondering,
Would a long term vaccum on an ammo can pull the air out of the cartridges?
And if so, what effect would it have on the cartridge when it was fired? Isnt the oxygen within the cartridge case needed for combustion?
I honestly don't know and am asking?
Thanks, catpop
Click to expand...
The powder is self oxidizing. Meaning it creates everything it needs to burn once the heat is applied.

I actually read a test that they created a vacuum inside cartridges & compared them to those without. IIRC there wasn't any difference.
 
Catpop said:
Just wondering,
Would a long term vaccum on an ammo can pull the air out of the cartridges?
And if so, what effect would it have on the cartridge when it was fired? Isnt the oxygen within the cartridge case needed for combustion?
I honestly don't know and am asking?
Thanks, catpop
Click to expand...
Even if it did and the powder didn't make it's own oxygen to burn, I imagine that opening the ammo can would fix that problem.

What I'd be worried about is putting the can under vacuum and the bullets being pulled from the casings.

If you really want to purge the ammo can, get a bottle of 100% Argon. Fit a valve in low on the can to put the argon in and a much smaller valve on the lid that will let air out. Crack the outlet valve and start filling with argon at a very slow rate. Argon is heavier than air and will eventually fill up the can by pushing air up and out. Close both valves at the same time. Simple tire valves or other one way valves won't work as changes in atmospheric pressure would let argon out and/or air in. You need valves that won't allow air/argon to move in either direction. And when you go to open one of the cans I would suggest doing so in an area with decent ventilation. You won't be letting out a ton of argon when you open one but in a confined space you could be letting out enough that you take an unwanted nap, or worse.

Nitrogen would work just the same, but nitrogen is lighter than air so you'd have to fill the can from the top and vent from the bottom. But if the flow rate and vent rate aren't correct nitrogen will actually settle under air. The benefit of using nitrogen is that air is already 75-80% nitrogen and opening a can in a confined area wouldn't have as much risk as argon.
 
I just use homemade desiccant packs. Typically I use 100% silica jell premium cat litter, but have also used flower drying material in the past. Fill either a small pouch of cheese cloth and zip tie it closed, or staple some in coffee filters.

Put them in ammo cans as soon as I make them, seal it up and brass stays nice and clean. Got some ammo going on 10 years now that is just as nice as when it was new.

(I live on the Gulf coast, so humidity and heat are a way of life here.)


.
 
GBExpat wrote:
Keep in mind that such exhaust is also loaded with moisture ... think, exhaust plumes from the tailpipes on cold days.
Click to expand...

The steam component of exhaust plumes from automotive tailpipe on a cold day come from moisture that has condensed inside the hot exhaust system as it cooled off from its last use and which is being vaporized and expelled by the engine as it warms up. Moisture from such condensation is the reason why automotive exhaust systems were so prone to rust until the industry switched to using stainless steel. The same conditions don't exist in a small air cooled engine as the exhaust system comes up to temperature almost instantly (run one for a minute and touch the muffer) and so do not retain the large amounts of moisture found in automotive systems.

There is mositure in the ambient air that is sucked into the air intake of the engine that may proceed as water vapor into the exhaust, but it is the same quantity of moisture that is present in the ambient air and that's what the dessicant pouches are used to manage.
 
TrickyDick said:
Ever thought about drilling a hole and installing a tire valve stem? Perhaps you could vacuum seal the box.
Click to expand...
This ^^
Cheapest and most effective way I've found to store I use what are basically larger plastic mason jars with air tight gasket lids, made for storing coffee or sugar etc. I get these for about $2 at Walmart. I then Go a few aisles over and get a $5 pack of valve stems and a $2 tube of epoxy. Fill the jar with your ammo, drill a small hole in center of lid, insert valve stem, epoxy it in place and let dry. Place lid on container and then take a Small length of cheap air hose and attach a make fitting to one end. Connect the fitting to a valve stem filler attachment like you use to fill your tires off your compressor. Grab yourself a small computer vaccum or kitchen vaccum sealer and tape the open end of the hose to the suction port on the vaccum or sealer. Connect the other end to the valve stem and turn on the vaccum/sealer, then approach as you would when filling your tire except you will be doing the opposite. I usually suck out air until I see/hear the sides of the container crinkle inward and then turn off he suction device. After that I then depress the needle in the valve stem once or twice for a brief millisecond just to vent a little pressure out, but that's a personal preference. (I just don't want my ammo squeezing together super hard for years and years personally) To each his own though. In the medium size containers I can fit about 3200rds .22 LR, ~800rds 9mm/750 .45, 550rds 5.56, 325rds .308/.300 Savage. These are a little larger than standard coffee cans and store quite well. I don't do this for all of my ammo, but I keep a good stash sealed up this way and stored seperstely from the rest of my gear as a "just in case" stash. Good luck, and hoard/prep on!
 
hdwhit said:
The steam component of exhaust plumes from automotive tailpipe on a cold day come from moisture that has condensed inside the hot exhaust system as it cooled off from its last use and which is being vaporized and expelled by the engine as it warms up.
Click to expand...

This is completely incorrect.

Burning - combusting - any hydrocarbon produces water as a reaction product. That's high school chemistry.

Making a gas tank inert for welding either by purging with exhaust fumes or filling with water only serves to eliminate the combustible mix of gasoline vapor and oxygen. It does NOT render the volume oxidatively inert in the context of sustained storage of ammunition.
 
An ammo can with good gasket and a valve stem added to admit a SLIGHT positive pressure of nitrogen, argon, or carbon dioxide sounds best to me. Purge the system with an excess of inert gas before clamping down the lid.

Agree with Varminterror, combustion produces water vapor.
I worked on a project in a ca 1951 plant with piped inert gas system and it needed a LOT of inert gas. It was produced by burning natural gas (mostly methane) in air (mostly nitrogen and oxygen) to produce a mix of nitrogen, carbon dioxide, carbon monoxide, probably some unburnt natural gas, and water vapor. It went through dessicators to remove the water vapor. The resulting dry N2, CO2, and CO blend was nonreactive to the plant product but was toxic. Since the plant also had piped breathing air, dedicated noninterchangeable fittings were used to keep you from getting a snoot full of carbon monoxide when suited up.
 
I just opened a GI ammo can of 200 gr lead SWC that I loaded about 15+ years ago that has been sitting on a shelf in the garage. Must have loaded them on a warm day, its in the 50s today, can was effectively vacuum sealed, had a tough time opening it and got a whoosh when I finally broke open the gasket seal. Ammo looks as good as what I loaded last week, so yeah, I'd say he is seriously over-thinking this!

This was my go to load back in the day, but as I got other .45s that weren't 1911s some didn't care for the SWC profile so I've been loading 200 gr RNFP or 230 gr RN and quit buying the SWC bullets. Been out of the 200gr RNFP for a good while but have plenty of 230gr RN so that is what I've been shooting in .45, but I strained something in my right hand doing some home-owner repairs and wanted the lighter recoiling 200gr loads so I dug these out. Was happy to still have some ready to go.
 
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