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Letter Re: Fireproof Document Boxes, Mold, and Rust

Dear Editor:
The suggestions of where to hide money prompted me to write about my experiences with storing cash. I keep on hand a few hundred dollars in small denominations in the event of an interruption of cash supply . I keep the cash in a small home fire/water proof lockbox from Sentry (just large enough on the interior dimension to fit an 8.5x 11 sheet of paper, and about 2 inches deep) along with other papers I want to protect from fire. The small size obviously offers no theft protection so to secure it, as well as up the fire protection, I put the lockbox into a fireproof gun safe. I always felt that this was the best way to store it until I ran into a little problem.

I infrequently open the lockbox just because the nature of what’s in it isn’t needed often. Once after a couple of months I opened it to find that the currency had molded (not mildewed) while sitting in the lockbox. It was my first experience at laundering money.

I take two steps to avoid this problem. First I place the money in an envelope and vacuum seal it. Secondly I place in the lockbox, about a half cup of silica gel desiccant, with indicating beads, in a coffee filter and check the condition every few months replacing as needed.

I’ve never had any corrosion problems with any of the firearms in the safe so I have to assume that the issue is with the lockbox. In my mind either the rubber seal allowed the currency to draw moisture from the humidity in the air, or the currency had enough moisture in it to cause problems when it first went into the lockbox.

I thought this was something that could save someone a little heartache. - Kentucky Possum

JWR Replies: If your document lock box is marked "fireproof" then it probably has a moisture-bearing insulation, typically Calcium Silicate. The moisture is part of what makes it fireproof.) This insulation BTW, will eventually induce rust on your guns if stored in the same vault, unless you take precautions. Place in the vault either a large (1/2- pound) bag or canister of Silica Gel (rotated by drying in an oven or in a food dehydrator at 160 degrees F overnight, four times a year), or use a Golden Rod dehumidifier, continuously.

The same types of linings are used in "fireproof" file cabinets at gun vaults. And coincidentally, because these linings eventually lose their moisture, their "fireproof" ratings expire after a few years.

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