Hello all, I came across this forum and wanted to share some information about gun storage in particular "gun bags" with VCI technology.
first off, in the spirit of full disclosure, allow me to introduce myself. My name is Mike and I am a packaging engineer from a company called Heritage Packaging in Western New York. We specialize in protective packaging with the majority of our work dealing with government and military contracts. One of our contracts was for a M16 preservation bag for the USMC. At the conclusion of the contract we took the opportunity to make a consumer targeted versions of the bag. We called this product line Zcorr and it remains our only consumer product. As that, I have been assigned a mission to utilize "social media" to help educate and interact with gun enthusiasts in order to establish a better understanding of gun storage options and of VCI technology.
So with that long winded introduction out of the way let me share some information about gun storage with particular attention to corrosion.
Why corrosion? Corrosion is irreversible. All weapons will corrode at different rates and different environments will cause weapons to corrode at varying rates. The goal is to prevent the corrosion from occurring by keeping water from coming in contact with the weapon while in storage.
The military actually came up with a solution to this way back in the early 1900's. By utilizing a paper with a nitrite compound within which would turn to vapor and create a weak polar bond with the metal they were able to effectively prevent water from gaining that same electron and oxidizing the metal. This technology known as VCI or Vapor Corrosion Inhibitor, since the 1900's has expanded into hundreds of other industries including in concrete to prevent re-bar from rusting, in nuclear power plants cooling systems, and in oil pipe lines.
More recently the industry has changed the compound from various nitrites to new formulas due to health concerns and then proceeded to impregnate the VCI's into polymers which are more durable than paper.
To sum this up, VCI technology works. It has proven science behind it and has had 100 years of use in various industries.
Now to help you further understand how you as a gun enthusiast can gain the most out of this technology, allow me to respond to some comments that I found on this site from quite a while back.
These can be found here:
should i grease the inside of the barrels?
No, VCI vapor can get places even where grease or oil cannot. You will not need to grease any metal in order to prevent rust.
if I needed to store firearms long term, I would use a different method. After a good cleaning and lube, I would vacum seal them inside a couple of heavy plastic bags and then put them in a case. Use a bore dessicant tube
"plastic" bags will not keep out water vapor, this is a common misconception, but you can actually look up charts for "water vapor transmission rates" to see how much water will get into your particular bag over time. Vacuum sealing these bags would actually increase the water vapor transmission rate even though the initial moisture level in the bag would be reduced. Also a bore desiccant tube is a bad idea. Anything that is hygroscopic should not be in contact with your weapon.
The military and industry no longer slather guns with grease for long term storage.
These days they use vapor-barrier paper and bags made of a special "hard" plastic that won't pass moisture or air, and prevents the vapor from escaping.
This vapor barrier system, when used with the special impermeable bags will prevent rust for at least 10 years.
Very close, but this is still inaccurate. by "vapor barrier paper" you actually mean VCI paper. The paper is not acting as a barrier to anything, the vapor is acting as a barrier to moisture. Also the "hard" plastic you are talking about, I think you mean polymers with a foil barrier layer. (see down below for more information on this). This is the type of material Zcorr uses for our gun bags and I believe we are currently the only company who offers it impregnated with VCI.
I've learned a lot about moisture ingress because of my work over the last several years. For long term exposure, it turns out that there are only two classes of materials:
Class 1. glass & metals
Class 2. everything else (dirt, wood, rubber, high tech plastics ... blah, blah, blah)
The first class will actually stop moisture ingress for most practical purposes, the second class will only slow it down.
This is somewhat correct, however a bit outdated. Modern technology blurs the line between the two "classes" listed above. Zcorr bags are whats called a foil barrier polymer. Its very much the same as MRE packets or many of the pouches you can find at your grocery store for products such as tuna-fish. Basically by sandwiching a thin layer of foil between many layers of plastic you create a "flexible can" which can be sealed and will act as a 100% barrier to water vapor.
one more that I've read in a few places:
How can this bag prevent rust if it uses velcro and therefore is not air tight?
Because the type of VCI that we use is a low pressure vapor it emigrates the bag at an extremely slow rate. Something like straight nitrogen is a high-pressure vapor corrosion inhibitor which must be sealed 100% air tight (we use this for many expensive military items such as our C-130 engine preservation kits) If that high-pressure nitrogen is not sealed completely it's effectiveness is reduced very quickly. Now another important mention is that the clear "poly" bags without the foil layers not only allow water vapor to pass through them but also the VCI vapor, therefore the lifespan and effectiveness of the VCI is reduced regardless of the type of closure used.
If anyone has any questions please feel free to ask. I am extremely knowledgeable on the subject matter and can get as simple or as technical as anyone desires. Also, for more information, pictures, and diagrams click on our facebook link in my signature. If anyone found this information useful I encourage you to let us know on our facebook page and interact with some of the stuff we have on there.