Carbine preservation

I was lucky enough a while back to come across an unissued-condition, all-correct very late Inland. Has factory-installed bayonet lug and adjustable sights, appears to have never been fired.

Anyway, my wife came home with one of those vacuum-bag food sealer gadgets. Been eyeballing the thing considering whether vacuum-bagging this carbine would make sense. it's coated in preservative (Boeshield T9). I can easily fit it and a mag or 3 along with a desiccant pack in a length of the bag material, as long as my wife's not looking (she thinks the bag stuff is expensive, but hey, so's the carbine...). I tried it, seems to work well, but recommend padding the slide handle so it won't poke a hole in the bag if abraded.

Anybody have thoughts if this is a good idea?

I know they stored carbines in VCI paper bags, but am unsure about the vacuum bags. I always use Breakfree CLP and a silicon gun sock.

Several people do it and have reported no ill effects . Leave the bags a little long so you can open , check , maintain , and reseal again to save bag expence . Extreamly good idea if it storm / flood area / times. Safes are not water proof . Not real expensive if you buy the bulk roll cases. I think I could do 100 assorted pistols , carbines , rifles , and belt feds for under $3 each on average ( it may have been much less ) .
Chris

I use the Breakfree for day-to-day use, but prefer the Boeshield T9 for longer storage. It leaves a drier waxy coating that stays in place. It comes off with any solvent, even regular gun oil. I found the stuff when I was doing saltwater sailing. It stood up to saltwater on a lot of stuff.

Went and checked the vacuum-bagged carbine last night. Bag leaked.. Found that a sharp corner on the magazine I had put in with the rifle had chafed a tiny hole in the bag. So, I guess anything put in a bag needs to be wrapped in something to protect the bag from sharp edges. I had put a piece of foam on the op-rod handle, but missed the mag. Guess oiled paper might work for that?

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Originally Posted by Mizzouboy

Guess oiled paper might work for that?

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Or cardboard??

Oh wow. This is a good idea. I think I will do this with some things I don't use very often that will fit. My house hasn't flooded in years, but it is a possibility. It's just where I live.

Do not use any type of paper, i.e. cardboard, unless you know it is acid free.

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Originally Posted by Mizzouboy

Went and checked the vacuum-bagged carbine last night. Bag leaked.. Found that a sharp corner on the magazine I had put in with the rifle had chafed a tiny hole in the bag. So, I guess anything put in a bag needs to be wrapped in something to protect the bag from sharp edges. I had put a piece of foam on the op-rod handle, but missed the mag. Guess oiled paper might work for that?

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Take the mag out! Put in treated gun sock, then bag! JMHO GK

I would be reluctant to seal a carbine and leave it. I know individuals who did this and they had massive damage to the weapon when they decided to take a peek and see how things were holding up. The Army went to great lengths to perfect a system for long term storage. If you look at NOS M1 Garands, they were simply coated with preservative, wrapped in paper and put into a wooden box. Enclosing a weapon in a non breathing plastic wrapper is asking for rust in my opinion. You can buy dehumidifiers (small heaters) for gun safes. Mine has two although I never plug them in. Keeping a weapon rubbed down with light oil works very well. The secret being to always wipe them off after handling and making sure some oil remains in the pores of the steel.

They make O2 absorbers for cheap that can be used in the sealed package. They're typically marketed for food, but would work for arms I guess. Not sure of the composition of the grease, but the little packages draw out Oxygen in a sealed environment trapping it in the compound that's inside the little package. No Oxygen means no oxidation.

I believe I read that hand warmers are O2 absorbers on a larger scale.

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Originally Posted by DaveHH

.....................always wipe them off after handling and making sure some oil remains in the pores of the steel.

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Ditto, anything else is unnecessary.

They also sell dessicant packs for gun safes. GK

Don't do it ! And this is why, a vacuum bag put 1500 lbs per square inch on whatever is inside, with that force it is possible to crush the stock and even bend steel. You could do some real damage. I've use these to make laminated plywood forms . Just remember "the road to hell is paved with good intentions "

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Originally Posted by phillydude

a vacuum bag put 1500 lbs per square inch on whatever is inside,

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The ones you buy at wally world that you use with your vacuum cleaner? I use 'em to draw glue into cracked stocks,,never crushed one.

They too can cause damage, as long as you put filler blocks inside the stock to prevent the sides from collapsing

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Originally Posted by phillydude

Don't do it ! And this is why, a vacuum bag put 1500 lbs per square inch on whatever is inside, with that force it is possible to crush the stock and even bend steel. You could do some real damage. I've use these to make laminated plywood forms . Just remember "the road to hell is paved with good intentions "

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If atmospheric pressure (outside the bag) is only 14 lbs per square inch relative to a vacuum, how is this possible?

Yeah, I agree that it would be about 14.7 PSI, if you had close to a perfect vauum. - Bob

USGI is correct that approximately 14.7 psig (standard atmospheric pressure) is the maximum differential pressure that will be applied to the stock if a perfect vacuum is achieved within the bag. But, you will not get close to a perfect vauum in the bag with a floor sweeper. That being said, phillydude is not entirely incorrect (except for the 1500 psi) when he notes that damage can be done.

Pressure (force applied per unit of area) can be a very counterintuitive condition if you are not accustomed to working with it. 1000 pounds of force sounds pretty nasty. Only 1 pound per square inch of pressure on a 33-inch by 33-inch surface sounds pretty benign - but either way the actal resultant force to be resisted is 1000 pounds. In addition, there are structural considerations to be considered that are even more critical than the pressure (vacuum) force considerations (i.e you couldn't damage an iron bar in a vacuum bag but you might damage a balsa wood model). Bottom line - applying 1 psig of pressure to a surface that can support only 1/2 psig of pressure will result in the same failure as applying 1500 psig.

I doubt that a vaccum bag would damage most assembled firearms but I do agree with phillydude to the extent you should look at what you put in the bag and if there are any thin and/or projecting wood sections that will be 'squeezed' by the bag you should take steps to support them before you evacuate the bag. Telescopic sights and batteries in scopes and lasers might be other issues to be considered. Maybe 99% of the time it's no problem but after you break it or permanently warp it it's too late to figure it out. JMHO ChipS

I don't think it works quite this way . If it did , you'd not be able to inhale with your muscles with all that pressure on your chest.
Most of the voided air space will be taken up by the bag forming to the gun's shape . Any air left in the bag will be shrunk to a space to yield 14 psi air pressure inside to meet outside pressure. If not , the plastic bag would rip , not the stock or barrel collapse .
Chris

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Originally Posted by emmagee1917

I don't think it works quite this way

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With all due respect, it pretty much works exactly this way. It is more complicated than as discussed here but the mechanics presented I believe are factual.

As you noted, at rest the air pressure in your chest is the same as the air pressure outside your chest. The only work the diaphragm and chest muscles have to do during breathing is to overcome friction loss in the airways and maybe the stretching of the lung tissue, which in normal healthy lungs is minor. That's why they developed the SCUBA regulator, to equalize the pressure in the lungs to the higher water pressure at depth so the diver can inhale and exhale.

However, regarding the pressure inside the sealed and evacuated bag, it is something less than the 14.7 psi (+/-) atmospheric presssure outside the bag. That's why they call it a vacuum. Using a common vacuum cleaner as a vacuum pump, the pressure in the bag will not be true (not gauge) zero, a perfect vacuum, but it will be something less than the '14 psi' outside of the bag. The forces resulting from the pressure differential that are not resisted by the solid material in the bag will be resisted by the diaphragm tensile strength of the bag material - which for modern plastics can be quite high. It's the same principle as the pressure hull of a submarine except the hull (a vessel) is in compression and the vacuum bag (a diaphragm) is in tension to balance the (lower) internal and (higher) external forces.

If you reduced the internal pressure enough the bag would rupture as you noted, but the vacuum cleaner cannot provide that much vacuum (except as noted below). If you reduce the internal pressure at all the bag will collapse in every dimension to reduce the internal volume, trying to re-equalize the pressures. When the bag collapses on a sharp point (like the corner of a magazine) a very high point load is exerted on the bag at the point of contact, exceeds the strength of the bag material and perforates the bag. It does not take much vacuum to make this happen on a very sharp point in the bag (think about an ice pick).

Like I said, the detail mechanics of this issue are more complicated than we have discussed and nobody here really wants to hear about them, but I think the general principles (and common experience examples) I have noted are pretty much true. There is an infinite number of shapes and materials that could be placed in a vaccuum bag and we can't generalize on whether they all will or will not be damaged. I don't think an assembled firearm would normally be damaged in a domestic service vacuum bag. My only point was that if there are any thin, weak unsupported sections or projections of a wood stock (like the thin highwood area on a carbine), or of anything else placed in the bag, they could deform or break if not supported prior to evacuation. Done, Peace, Out. ChipS

I think the most one could hope for when pulling a vacuum on a bag with a solid non-flexing content may be as high as 10 to 15 in hg? Not enough to damage the bad with the slide or other edges on a carbine.

FYI, there are two sides to a SCUBA regulator; a high side and a low side. The high side is tank psi and the low side is 140 psi max. The second stage regulator from which you breathe uses that 140 psi with an orifice and a lever controlled by a silicone diaphragm so when you inhale the diaphragm is drawn inward to actuate the lever which opens a valve and allows air to flow to your mouth. :)

I feel like I'm back in my physics classroom. Good explanation.