By March 6, 2012

How to make your own desiccant packs

“Rust never sleeps.”

Such a simple phrase, but something that makes firearms owners worry. Firearm collectors lament the cosmetic damage done by surface rust, but those of us who also own guns for self-defense have more practical worries. The last thing I want to think about if I ever have to defend myself with a firearm is if it’s too rusted out to function properly. Barrels and firing pins are particularly sensitive to the effects of rust.

Corrosion is bad for ammunition, too. A lot of my handgun ammunition has steel cases — it’s insightful to go to outdoor ranges and see the rust-encrusted shells all over the ground. Brass cased ammo isn’t safe, either; I periodically go through the ammunition in my shotguns, rifles, and carry handguns to check for green tinted oxidation. Corrosion can weaken the integrity of the shell itself, or it could cause irregularities in how tightly the bullet is seated to the case. The latter may cause a huge problem, especially in higher pressure handgun loads like the .40 S&W or .357 Sig.

You have to be concerned about rust if you’re a safe and responsible firearm owner. There are a few things you can do to minimize corrosion to your firearms and ammunition. For example, allowing your gun to fully air out after cleaning is important to reducing problems with your self-defense ammunition. Touching the metal of your firearm or ammunition as little as possible is helpful, too.

The biggest thing you can do, though, is to keep moisture away from your guns and ammunition. This is where desiccant packs come in.

You probably already have some desiccant packs around the house. They are those little white paper bags that come in coat pockets, computer components, and sometimes in bulk food. “DO NOT EAT” is usually printed on the paper pouch. Silica isn’t poisonous except in extremely high amounts, but apparently enough kids think the crystals are candy that the warning gets stamped all over the pouch.

Anyway, there are three ways to add desiccant packs to your firearm safes and/or locked ammunition boxes:

  1. Save up a shit ton of pre-made packets over time.
  2. Buy pre-made packets online at places like eBay or silica desiccant retailers.
  3. Make your own and save a ton of money.

I’m a price-to-performance kind of guy. After trying the first two methods over the years I wound up going with option three: making my own.

Here’s what you’ll need

  • 4-cup “Junior” paper coffee filters. It doesn’t matter if they’re bleached or not. I like these by Melitta USA.
  • 100% pure silica desiccant. Don’t get a hybrid / mix of silica and other elements, like clay. Avoid regular kitty litter, even if it says “silica” on the packaging. You want to get 100% silica, like Amazing Cat Litter, which comes in 8 pound bags.
  • Tape or staples
  • Tablespoon measuring spoon


This process is simple, but I made a video just in case you want to see what I do:

  1. Place a single paper filter on a flat surface.
  2. Scoop two level tablespoons of desiccant into the paper filter. This will be about 10g of desiccant, well over twice the recommended amount for a .50 caliber ammunition can.
  3. Fold the filter in half like a taco.
  4. Fold the left side towards the center of the taco. The filter should sort of look like an “L.”
  5. Fold the right side of the filter towards the left side of the filter. The filter should now look sort of like a burrito, with the “top” open.
  6. Roll the filter from the bottom to the top.
  7. Apply a small amount of tape to keep the pouch shut. You don’t want too much tape, as it could reduce airflow through the desiccant pack.

Cost effectiveness

Okay, so it’s easy — but is it cost effective?

Amazing Cat Litter comes in an 8 pound bag and costs about $18 shipped from You can scoop out over 360 desiccant packs with this amount, which brings the per-pack cost of silica to $0.05.

The 4-cup filters are 100 to a pack, and are $3.45 delivered. That’s less than $0.04 per filter.

I didn’t count the cost of the tape, and I assume you already have a tablespoon measuring scoop around the house.

That means a do-it-yourself desiccant pack runs less than a dime. Total cost for 100 10g desiccant packs: $9

As of this writing, you can buy 300 gram’s worth of pre-made desiccant packs on eBay for about $19 delivered. That’s $1.90 per 10g pack, or 21 times the cost of doing it yourself. Another vendor on eBay is selling 20 packs for $6, but with another $6 in shipping. That’s $0.60 per pack.

I found 10g packets from desiccant vendors for as low as $0.22 before shipping — but that’s typically in a case of 600 or more.


The biggest problem with making your own desiccant packs isn’t the cost, or the mess (which is minimal). The problem is what the hell are you going to do with 8# of silica? I have a fair amount of ammo put away for training, but even then I only needed a fraction of what I could make. Due to a shipping error, Amazon sent me two eight pound bags.

My advice is to get together with a few of your gun-owning pals and make a bunch of packets. It’s easy to do, and that eight pound bag may disappear in no time.

Strongly recommended

Posted in: guns, preparedness

1 Comment on "How to make your own desiccant packs"

Trackback | Comments RSS Feed

  1. Phoebe says:

    Awesome, I started to read your instructions really carefully; expecting some prepping/cooking or other intense methodology.

    Then I was all like, “yay, simple silica burrito!” and I put that litter on my shopping list. It’s so damp humid here that I fear for my stuffs every day.