I have been asked to do a demonstration for a local historical group on mining/quarrying. They want to see how a blasting borehole was drilled by hand. I guess I am the go to guy around here for industrial archiology also known as "doing things the hard way". My problem is my 11/4"x3' star drill that has been stuck back in the barn forever has grown legs and I can't find another one. I suppose I could use a smaller one that you get at the hardware store but I really want another big one cause I have actually used it to drill and bust rock with a feather and weadge set. Anyone know where I can find one of these or if they are even still manufactured? I could forge one but that will take more time than I can put in right now.
Could you buy a short one and weld a bar to it? I bet you could cet a short one at a concrete tools supply. I have a shot 1 1/4" at home thats about 12" long that i picked up somewhere back when I was doing concrete work many years ago.
All I've got are the short ones as well. I've not seen any longer ones around. I'm surprised I haven't found one at the quarry at work. We've found a ton of worn out saw blades, forged hooks, and even a hand set. 8) I'd like to see a video of your rock drilling, that would be cool. 8)
Lee do you think a bar welded to a shorter drill would hold up? Dave If I can lay my hands on a drill and can get somebody to film I will try to post a video of the whole thing.
I can't say if it would or not. The only real problem I see, and I don't know what I'm looking at, is the weld breaking between the hardend steel of the bit and the soft steel of the rod. Having said tat, wouldn't just the tip of the bit be hardend? How does one do this drilling? Hammer, turn, hammer, turn, clean out the hole? All I ever used mine for was a chisel. :D
You can either do it with one man (called single jacking) or with two people (double jacking) and you pretty much figured it out- hammer, turn, hammer, turn, hammer, trip to the hospital for the shaker :D (thats the guy who does the turning of the drill so called because after every hammer blow he gives the drill a "shake and a turn") every so often water is added to the hole to make the rock dust into a "mud" so it sticks to the drill and can be removed from the whole.