I'm wondering if anyone has had much experience splitting or breaking up large rocks which are too big to move with their tractors. I've split a lot of smaller stuff (up to say 3x2x2 feet) by drilling 3/4" holes in a line using a small rotary hammer, then cracking them with 4" feathers and wedges driven into the holes with a sledge. However, I'm currently trying to remove a larger boulder that's right in the middle of a path I'm constructing (and unfortunately, I can't simply reroute the path). This thing is at least 6'x4'x3', and the wedges aren't splitting it.
I've spoken with local rental yards about using a larger jackhammer to break the boulder up, but they didn't think it would work; although I can very slowly chip away at the rock with a chisel mounted in my rotary hammer, it's much harder than concrete. The rental guys suspect the steel in their jackhammers would just mushroom when used on solid rock.
A sledge hammer doesn't make much of an impact either; at best, I occasionally get some chips loose, but it would take months to make any real progress.
I checked with masonry tool suppliers; they've got larger feather and wedge sets (1" to 1 1/2" diameter, and up to 24" long), but I'm not sure how I'd ever drill the holes for those (they definitely exceed the capacity of my 7/8" rotary hammer).
Anyone got some suggestions? One of the rental yards mentioned using "Bentonite" (sp?), an expansive compound you pour into holes to crack the rock. They didn't carry the stuff, however, and didn't know who might. My other idea was to excavate beneath the edge of the boulder, then try to gradually raise it with larger hydraulic bottle jacks, and eventually tip it to the side of the path. Not sure how safe that alternative would be.
Thanks for the help.
AndyH
I've spoken with local rental yards about using a larger jackhammer to break the boulder up, but they didn't think it would work; although I can very slowly chip away at the rock with a chisel mounted in my rotary hammer, it's much harder than concrete. The rental guys suspect the steel in their jackhammers would just mushroom when used on solid rock.
A sledge hammer doesn't make much of an impact either; at best, I occasionally get some chips loose, but it would take months to make any real progress.
I checked with masonry tool suppliers; they've got larger feather and wedge sets (1" to 1 1/2" diameter, and up to 24" long), but I'm not sure how I'd ever drill the holes for those (they definitely exceed the capacity of my 7/8" rotary hammer).
Anyone got some suggestions? One of the rental yards mentioned using "Bentonite" (sp?), an expansive compound you pour into holes to crack the rock. They didn't carry the stuff, however, and didn't know who might. My other idea was to excavate beneath the edge of the boulder, then try to gradually raise it with larger hydraulic bottle jacks, and eventually tip it to the side of the path. Not sure how safe that alternative would be.
Thanks for the help.
AndyH