Bomb Building 101

[chrisinhouston]

Today the headlines have pictures of a mangled piece of a home kitchen style pressure cooker that may have been what made that horrible explosion in Boston. It got me thinking about when I was younger and my best friend taught me how to build a bomb. I'm 57 now so this was when I was like 15 or so.

My best friend back then was a kid named Bert, had a crazy family so he was a bit strange. His dad had been some kind of machinist so they had an incredible home workshop complete with a welder, a metal lathe and other non typical home shop tools and Bert knew how to use them. We used to go to an old Army/Navy surplus store... the kind you don't see now as this one had real surplus from WWII, Korea and Vietnam and not made in China knockoffs. We used to buy manuals on making booby traps and explosives. I think that's where Bert learned to make really good bombs. We also bought cool helmets, bayonet and other neat things that every teenage boy would like.

His specialty was the pipe bomb and Bert discovered that while pipe bombs made from galvanized plumbing pipe were ok, a seamless pipe with a higher tencile strength was better. He figured out that the best material was bicycle frame tubing which is seamless; the seam is the weak link and will tear apart so having no seam makes the bomb build up greater pressure. Threaded pipe caps are also a weak link so Bert would bend and roll up the ends of his pipe bombs much like the end of half full tube of toothpaste. This is why a pressure cooker did so much damage, probably high strength stainless steel with a tight locking lid. Bert and I were always finding old discarded bicycles and we would cut them up into various size lengths of tubing.

As for what to use to make it explode, it's easier then you think. Gun powder for reloading bullets or shotgun shells is easily obtainable at most gun shops. We came up with a cheaper and easier solution; matches. There was a clearance place that sold things bought up from places going out of business or being rebranded. And back then matches with a hotel's name on them were everywhere, the disposable lighter was not yet on the scene. So, Bert and I bought cases of paper matches. And we would sit at a table tearing the books apart and cutting the stems from the match heads into a container. And that was all we used, we packed the pipe tightly with matches. Oh and the fuses were made from matches. We would take a long piece of masking tape and lay it on a table sticky side up. Then lay the small parcels of matches torn apart from the booklet onto the tape in one long line of match heads. Fold the tape over on itself and trim off the match sticks and you ended up with a long fuse.

So, were we urban terrorists? Well we never blew up anything of consequence. I remember there were some old abandoned cars in the woods near our homes. Cars from the 50's and 60's. We used to put bombs in them and set them off and see the damage. I think we put a big pipe bomb in the hollow of an old tree and blew that up. It's amazing we weren't killed or maimed. We would light the fuse and run like hell. We usually wore our Army helmets for protection.

Later Bert learned how to make nitro glycerin and other more volatile explosives, he also somehow got some blasting caps and figured out that a little bicycle lamp generator (the old kind that had a wheel that was spun by the bike tire) made enough current to detonate the cap.

We never got arrested or blew up mailboxes or anything like that. And what happened to Bert? He became a Christian minister of some kind, I last heard from him about 15 years ago. He was preaching at a little church in Georgia and also restored violins as a hobby. No kidding!

Funny, I've never told any of this to my kids or grand kids or showed them how to make a bomb. Grandpa's secret I guess...

[footfootfoot]

Chris, you and I would have got along like a house on fire. I discovered the match thing too, gunpowder and shells were unavailable to me as a kid living in a small city. We'd use wooden matches and scrape the sulfur into a container.

Living in a densely populated area it was tough to find a place to conduct my tests so I built an oak and plywood box that I would use to test my bombs. They were much more modest than anything you guys built.

I think I've mentioned this before, but my high school physics teacher said I was the only student he'd ever had who used the words 'blow-up' and 'experiment' interchangeably.

I was always in it for the bang and the physics of it, never for its anti-personnel potential.

I saw some footage of the explosion and it seemed that fireball went upwards, but all the leg amputations suggest to me the seal of the lid failed directing the energy horizontally rather than in all directions.

The gasket/lid area would be the weak spot, unless they thought to groove the body of the cooker to create weak spots. (can't recall the term for this at the moment, like the old fashioned pineapple grenades)

Bert sounds very creative in his problem solving.

I've not told my son about this chapter of my life, but we did make our own black powder for our science experiment, and put it in a bamboo tube and made an M-80 looking thing.

[glatt]

I made tennis ball cannons as a child, but no bombs.

The closest was probably when I would take entire rolls of caps and fold them back and forth, accordion style, so that all the gunpowder parts would be all lined up next to one another. Then take a pin and push it through the center of all of them. I forget how I'd light the thing. That's probably how the whole thing fell apart. What I do remember was taking entire boxes of caps and hitting them with a sledgehammer on a concrete slab. Louder than a fire cracker.

In high school, my calculus teacher would talk to us about how to make pipe bombs. Then one day he stopped talking about it. I think he realized he was being too free with information that might get him in trouble.

[Undertoad]

we did make our own black powder for our science experiment, and put it in a bamboo tube and made an M-80 looking thing.

And you injured the Gorn! But you had mercy, and didn't kill him.

[chrisinhouston]

Yes, I agree about the seal on the pot being it's weak point but it is a clever device to use since it is designed to hold a great deal of pressure before bursting. I found this from a DHS memo from 2004:

Typically, these bombs are made by placing TNT or other explosives in a pressure cooker and attaching a blasting cap at the top of the pressure cooker. The size of the blast depends on the size of the pressure cooker and the amount of explosive placed inside.
Pressure-cooker bombs are made with readily available materials and can be as simple or as complex as the builder decides. These types of devices can be initiated using simple electronic components including, but not limited to, digital watches, garage-door openers, cell phones or pagers. As a common cooking utensil, the pressure cooker is often overlooked when searching vehicles, residences or merchandise crossing the U.S. borders

[chrisinhouston]

Bert and I also used to drive from Atlanta to the Alabama border to buy big fireworks like M-80s. I remember being out driving one night, I was at the wheel and Burt would light a fuse and then shoot the firework out of our car with a sling shot. I remember one hitting the doorpost and flying into the back seat and going off.

Sometimes I can't believe I still have all of my fingers... I have had a few woodworking accidents that took off more of a fingernail then I would have preferred but that's about it.

[glatt]

That must have been loud. How's your hearing?

[footfootfoot]

What?

[Pete Zicato]

Originally Posted by chrisinhouston

As a common cooking utensil, the pressure cooker is often overlooked when searching vehicles, residences or merchandise crossing the U.S. borders

I bet they won't be overlooked now.

[infinite monkey]

I'm looking over
My pressure cooker
That I overlooked before...

[wolf]

I can say without hesitation that I never blew anything up during my childhood.

However, I did spend time researching how to build an atomic bomb.

I don't think that counts.

I did burn a lot of shit with a magnifying glass, though.

Oh, and because of the missing fingers comments ... I did have a friend who blew off his entire hand with one of his brother's homemade M-80s. His amputation was above the wrist. This put him into an specialty population on alt.sex.

[infinite monkey]

All we ever did was steal mercury and magnesium strips from the chem lab. I mean, you could just wander in and out of the chemical room at will. so long ago...

Mercury was just fun to roll around in your hand, and magnesium strips made the brightest flashes of fire!

[xoxoxoBruce]

The pressure cooker was aluminum, according to the news.

4th of July was the highlight of my year, as a kid. Extended family and friends would gather at Grandmas, stuff ourselves silly, big bonfire at dark, and fireworks. Real fireworks, big badda boom fireworks.

Sometime in the 50's, MA banned fireworks, but CT was a mile away. Later CT jumped on the do-gooder bandwagon, but it seemed one kin or another would be going to FL sometime during the winter and a stop at "South of the Border" was mandatory. My Pop and Uncles would always make sure they weren't going to be the one that brought home a poor show. Nobody wanted to be snickered at like opening your presents after Christmas dinner with a dull jackknife and tearing the paper rather than cutting the tape.

I think the worst injury was burned fingers from those damn sparkler wires, although I remember some tense moments when an 8oz skyrocket when wild and ended up under my Uncle's Mercury, bouncing up and down between the ground and the gas tank.

Anyway, one year something went awry, probably the recession in '58, and come 4th of July we had no fireworks. Grandmother rummaged around in her cellar and came up with a case of fucking quarter sticks. They weren't as pretty as the rockets, mortars, fountains and pinwheels, but shooting coffee cans out of a 4" pipe was amusing.

The rest of the year, when the stashed M-80s and Cherrybombs ran out, blasting caps and black powder, or cut open shotgun shells had to suffice.

Only used match heads in an ashtray with a pile of roaches to make a Turkey... but that was in later years.

[Gravdigr]

Well, if we weren't on a watchlist before, we are now.

[ZenGum]

Unburnt oxyacetalene gas in a plastic bottle, steel wool through the cap, current through steel wool...

Sparklers, crushed and powdered, packed around whip-it nitrous bulbs, all wrapped in aluminium foil, sparkler fuse ...

Brake fluid and chlorine, suddenly mixed...

Good thing we can't buy fireworks in Australia. Those things are dangerous, eh?

To be honest, I've merely been present for the first two, and only heard about the third.