There’s a dead maple tree in my back yard. There’s a hole in it about the size of a roll of quarters.
I packed the hole with about 1.5 oz of black powder, and stuffed it with some cotton wadding and a 6ft long wick made of string soaked in mineral spirits.
I lit the wick, got about 50 ft away and waited… and waited… waited… it took forever for the wadding to burn through, but when it did,
WHOOOOOSH!
It was very loud. A jet of flame and smoke shot from the hole about 6 ft across the yard. Blue smoke filled the air.
I didn’t get the “mini-dynamite” explosion I was hoping for, but damn it was cool. I was hoping to at least split the bough. Instead I only got a big black hole. lol
Gunpowder doesn’t blow up unless it is compressed. If it is simply put in an uncompressed pile and lit, it will produce the huge flame that you saw. I once lit a pile of 1/4 lb of black powder on the ground. Unlike you however, I didn’t have the good sense to light it using a long fuse; I just used a match. The resulting flash sent a fire-ball 10 feet tall and 15 feet across over my entire body. Witnesses thought that I had left them in this world although the only real damage was temorary flash blindness and a few flash burns on my face. In my defense, they told me that gunpowder put in a pile would just fissle.
DISCLAIMER: Don’t play with gunpowder. It’s dangerous.
Shagnasty is right; blackpowder must be compressed if you want it to explode. (Oh, a model rocket igniter would be a better ignition source than a fuse.) If you want to blow up the tree, you will need to contain the blackpowder. How do you do that? A plug? Yeah, I can see the plug flying across the yard like a musket ball. Not safe. And if you do work out a way to contain the gasses and actually blow up the tree, what about all of the flying splinters of wood? If you want to get rid of the tree, better to do it with a chain saw or an axe.
Ditto what Johnny said. Black Powder is a low explosive, and can behave in surprising ways. If you’re sufficiently enterprising, you just might make it go “bang” instead of “fwoosh”. Then you’ll have to contend with whatever comes flying out of the smoke cloud. Even if you are a safe distance away, what about all the other things that may not be safely far away: Windows, cars, stray animals, people wandering about? What happens if you manage to knock the tree over? What might it fall on?
Yes I knew about the powder needing to be compressed. I used a wooden dowel to stuff it in to the hole as tightly as I could. then I pressed the cotton wadding in the same way.
I dont know what the grain size is, but it’s about the size of sesame seeds.
There are two problems: I’ll start with the second one first. As you found out, the fuze burned through the wadding. No doubt the ignition happened on top of the powder, which resulted in the Fourth of July effect.
The second problem is that I didn’t mean that the powder had to be compressed. I meant it needed to be contained so that the pressure will build up to the point that it bursts the vessel it is in. Think of a hand grenade or a petard: The powder is encased in a strong container. When it is ignited, the resulting gasses amost instantly overcome the strength of the metal and the bomb explodes. Now think of a gun: When the powder is ignited, the resulting gasses overcome the friction of the projectile, sending it flying toward the target.
The thing about the tree is this: How will you contain the explosion? As I said, a plug will become a deadly projectile. I suppose you could put in a plug and then wrap a band of iron around the outside, but it seems like a lot of work.
Really what it comes down to is that if you want to get rid of the tree, there are easier ways of doing it. If you just want to blow something up, then that’s a bad idea.
Evelyn Waugh (spelling) has a story reprinted in Max Hastings’s book of military stories through the ages, about his unit in WWII offering to blow up a dead tree on an estate where the unit was quartered. There was a miscalculation of the quantity of explosive need to up root the tree. A misplaced decimal point. 75 pounds of dynamite was used to do a 7.5 pound job. The tree was thrown 200 feet in the air and every window within a half mile broken. When the Lord of the Manor stepped into his bathroom to consol himself the ceiling fell on him. The whole story is told with Waugh’s stiff upper lip and understated style. “We may have used too much dynamite, Old Man.”
As a young lad, a friend and I came across a box of 1000 .22 blanks. We used a nail to open a couple hundred and laid out a swirl pattern on his dad’s 2 month old garage floor. Thinking all we would get would be a small time flash show, the gunpowder was lit. It took about 3 seconds for the entire swirl to go off. Besides filling the garage with smoke, it permantly burned the swirl into the concrete. Needless to say, his father was not pleased. We later used the rest of the blanks destroying an ant hill and tossing them onto a burning stump his father was attempting to remove. Ahh, the fun we use to have and didn’t kill ourselves.
The problem with the whale wasn’t the explosive solutiuon, just that they used too little, and placed them on the wrong side of the whale. Oh, and a bit more stand-off by the crowd would’ve been useful, too.
It’s very difficult to get unaltered gunpower to forcibly explode under any circumstances. It flashes, not explodes, and it is designed specifically not to explode.
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When I was young and stupid a next door neighbor and I would take tennis balls packed with some sort of powder(He made them, not me) light them and toss them into pools. They made an impressive splash. We also blew up other things, like tin cans and garbage cans. Fun stuff. We also once made a tennis ball cannon that shot balls really far concidering that it was a couple of kids.
I never helped him make the things because he and his Dad had a track record for blowing holes in their house. In fact, his Dad picked up a small booster rocket from Sandia Labs somehow. It was on the side of the house and they kept saying that they were going to get it running and fire it. Thankfully I moved away before they tried that.
At around 10 years old, one of my hobbies was making rockets powered by matchheads (the snipped-off heads from many books of paper matches). We’d secure wooden plugs into an aluminum tube with 3 screws, drill a hole in one plug for a combustion chamber, cobble up some sort of tailfins, pack 'er full of matchheads and ignite them with a fuse.
Now and then one would fly fairly far. Mostly, they blew up violently. In short, it was a complete success. (It’s a wonder we didn’t kill anyone.)
I was hoping to at least split the bough. Instead I only got a big black hole. lol