Powder storage box


May 15, 2008, 01:58 PM
I just ordered another couple of jugs of powder; it'll get here tomorrow. I couldn't pass up the good deal. This will put me over the limit for what I should have stored in my house. I'm going to move all the big containers (anything over 1 pound) to a big wooden box out in my detached garage. I already have the box; it's built like a footlocker out of 3/4" exterior-grade plywood, and it has a hasp.

Do I need to line the box with more 3/8" plywood to bring the thickness up to >1" to bring it up to current fire code?

Is it better to leave the box unmarked or to put one of those diamond "Explosives" labels on it?

Since I'm not going to store blackpowder in it, I assume one lock is enough?

Would it be a good idea to put a few hundred pounds of lead ingots in the bottom so nobody tries to steal it? :)


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May 15, 2008, 02:03 PM
Mark it so firefighters will know what they are dealing with in case of a fire. Mine is. You want an enclosure that can "blow open" easily and not create a bomb effect.

I keep some lead in the bottom of both my safes to add weight. I never have worried about anyone stealing powder. Maybe I should. I do lock up primers.

May 15, 2008, 02:10 PM
Bob, you mention the Fire Code. There are a bunch of different model fire codes available nationally for local cities/counties to adopt, and the codes are generally adopted with local amendments. No one on this Forum can help with your fire code question without reading the actual code adopted in your jurisdiction. Many municipalities list their adopted codes (and amendments) on their city/county web site. You should look it up, and call local Fire Prevention to ask questions. Fire prevention folks take the code seriously, and they won't lie to you like other public officials.

May 15, 2008, 02:31 PM
not sure about adding more wood to the box.by design the box should blow apart before it builds to much pressure.thats why most codes say a wooden storage box for powder. if you build it to tight,you've ,more or less,made a pipe bomb. jwr

May 15, 2008, 02:32 PM
As I understand it, the key thing about your box is that it should not be, in any way, sealed shut.

It should have a lid, or door, that is held shut by spring action or gravity, such that if the contents were to catch fire, the lid or door would open readily and release the pressure within.

The purpose of the wood lining is to buy time.

The purpose of the gravity/spring opening is to keep it from being a bomb once time runs out. Smokeless powder burns at a rate determined by its pressure. Keep the pressure from ever getting high, and it will just burn and never kaboom.

The suggestion I got from my fire department, when I called, is to buy an ordinary cabinet, hang it on the wall, and then line it with thick wood, but in such a way that the spring-loaded doors could still open and close unimpeded. This would meet the requirements of buying time, and yet not containing the hot gasses once the powder caught fire.

May 15, 2008, 02:41 PM
A wooden box will blow apart at the seams when the pressure inside rises to just a few psi. There's lots of square inches on each of those panels for the pressure to bear against.

I'm going to lock mine. If it was a metal box I'd use springs and no latches.

May 15, 2008, 05:40 PM
You're going to lock it. Why, as a burglar, aren't I going to just pop the side or top off with a crowbar and take what's in it?

If you build it strong enough that I can't do that, then you've just make it too strong to be safe: the seams aren't going to properly pop when the contents catch fire.

It seems to me that the requirements, Burgler-proof, and fire-safe, are conflicting.

May 15, 2008, 05:42 PM
It seems to me that the requirements: Burgler-proof, and fire-safe, are conflicting.

They are. I'm more concerned about kid-proof. I've got boys living next door. AFAIK they stay out of my garage, but I don't want to find out otherwise.

May 15, 2008, 06:02 PM
Fair enuf.

What are your potential liabilities?

Firefighter injured/maimed/dead after being struck with splinter from exploding box of smokeless powder...


smokeless powder stolen from unlocked box.

Isn't it the garage itself that should be locked, and not the powder box?

May 15, 2008, 06:09 PM
I'll check with the local fire marshall and see what he recommends (I may call from a pay-phone, LOL)

Actually, the smokeless powder is not nearly as dangerous as the gasoline, or acetylene, or oxygen, or cans of starting fluid, or... (but it's still worth some precaution)

May 15, 2008, 06:18 PM
Haha, yeah, I know it. Much ado about nothing, for the most part. The main reason to protect the powder is for home-owner's insurance. If my place has a fire, I don't want "code violation" to have anything to do with the investigation, or me getting paid so I can fix the damage.

When I called my fire department to ask the same question, the guy I talked to turned out to be a reloader himself--what are the odds? We ended up talking for probably 20 minutes (not from a pay phone, so they may have a tape of it). I ended up writing his boss a letter thanking him for the helpful advice. Nice guy.

May 15, 2008, 06:40 PM
I suppose a burglar might steal powder, but that doesn't seem like the sort of prize item he would go after (any burglar who sees bottles of powder and has enough voltage in his brain to bring two and two together will know that you almost certainly have valuable guns in your house- much more valuable than powder!).

I would build it safe for fires, instead.

May 15, 2008, 08:34 PM
I'd place the box as far as possible from where I normally keep my running shoes.

May 15, 2008, 10:54 PM
Lining the inside of the box with 3/4" fire rated sheetrock buys a whole lot of time before the fire can cause powder ignition. Most fireproof safes are lined with it. You still need a means of pressure relief though.

Steve C
May 16, 2008, 05:18 AM
Smokeless powder is a propellant and not an explosive. Read this information on Alliants website regarding storage of smokeless powder. http://www.alliantpowder.com/safety/storage.htm

Understand that BLACK POWDER is an explosive and needs different storage conditions.

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