New tool ! Demolition hammer

[a10 gf]

olev, thanks for the info. Had come as far as the bulb filament ignition idea. Your tips very helpful, just need to figure out the amount of powder. Maybe as easy as test with low charges and increase until one gets the hang of it.

Next year when back at the property (in F), plenty of boulders needing attention. Using BP, substantial savings compared to the Betonamite expansion stuff.

I'll be super careful. Not planning the loss of fingers or hands etc, nor damage cars \ house by flying debris. Thinking about acquiring a good piece of thick, heavy rubber mat, like I have seen used for dynamiting work.

And of course, boys loves explosions  so looking forward to this.

[muskrat]

G'day E.
Old conveyor belt works well.
A mate was a powder monkey down the coast. Lost count of the broken windows and holes in roofs 
Just be careful.
Cheers

[a10 gf]

^^^ "powder monkey"
  rofl

[a10 gf]

hmmm...  look at the hillbilly's flying large rocks when using nothing on top to absorb the blast...
Makes me think of staying with expansion cement, can take 3 days to split large stuff instead of 0.0001 second with black powder, but the danger of destruction or harm is zero. Will see 

[Black Sheep]

When I was a schoolboy some of us tinkered with home made explosives. My pal David managed to blow out part of his stomach. Took him weeks to die. Be warned. Since then I have only evr blown up rocks with plastic and det cord under very controlled conditions.

[a10 gf]

^^^ Yes, that. Would have given a 'like' but not appropriate.

At least made 2 definite decisions, if eventually going ahaed, absolutely zero activity before getting a collection of large, thick, heavy rubber mats.

& thoroughly test ignition systems on some micro charges, to get 100% control & reliability in that dept. > do not want to see something not exploding, then moving closer to inspect and .....

Also, had my fun with homemade pipebombs around the age of 12-13, made excellent black powder from at the time freely available ingredients, reading encyclopedias for recipes. Utterly ignorant and stupid + incredible luck, we survived, but one friend lost a finger (very, very lucky actually) in a major fail, pieces of steel flying around and embedded in wall & roof. Police and parents etc. A swift end for the chemical bomb-brother's fraternity.

[olev]

We are not talking sticks of gelignite here - more like fire crackers.
The only reason a fire cracker goes bang is because the combustion is contained in rolls of paper.
The idea of splitting a rock is to contain the bang inside the rock. The important part is containment.
We are trying to split the rock, not blow it to bits.
Done properly, there are no flying chips, just a dull thump.
If it fails to go off just draw it out of the hole using the wires. (hasn't happened yet)
Don't know if it makes any difference, we use smokeless powder.
If you are looking for a 'hold my beer' or youtube moment, this isn't the way to do it.
cheers

[a10 gf]

^^^

Done properly, there are no flying chips, just a dull thump.

Excellent. Yep, that's it. If I get going, will do systematic testing with BP dosage, starting with low charges (like what goes in my 44 revolver), then safely build up experience from there ...and look at a few more hillbilly yt videos to further grasp how to absolutely not do things.

[olev]

Gday Erling,
If you are heading down this path maybe I'll clarify a couple of things.
After you have had a couple of successes it becomes routine (but never boring).
It's good you intend to experiment with the size of the charge - the type of rock probably makes a difference.
The tube the suppository is made from is hard plastic. We tend to use black low density poly pipe like you use for plant irrigation.
Seal it well with silicon and fill the hole with water.
Quick and effective.
We've had some success with thin fuse wire as a det filament.
You can test the thin fuse wire with a small amount of powder in a spoon. It's the cheapest way to go.
We have heaps of bulbs though and tend to use them all the time now.
and stop watching hillbilly redneck powder monkey videos.
cheers

[a10 gf]

^^^ Excellent, thanks.