Splitting igneous Basalt using wedges and shims.

[abknight@zzzzzz]

I sent this privately to Mr. Holmes so I could attach
picture of a 45 degree spill with long rods in Japan but
wish as well to send it to the list in case anybody else
wished to pitch in, though I think I have brought the
insue of splitting at a 45 degree angle before.  One thing
I have learned since is to straighten the 45 light side
feather so the flare does not press at the very thinest
edge of the top or light side material.

David,

Pardon for barging in but I wanted to send you two
attachments of photos of Japanese what I'll call splitting
rods.  I have not done a lot of grantie splitting but the
split I oftenest want to make is on a bias or a lengthwise
diagonal one such as picture in "split 3" in order to
round the corner edges off of a squarish quarry block.
The problem with the 4 inch w/s is that it puts all the
pressusre right at the surface and in the case of fourty
five degree to the surface split the fourty five degrees
of material on the top side really likes to blow out
especially right at the surface were if gets really thin.
  I would think these rods have a very gently swell to
them that would make fairly deep contact.  I don't really
see how one could ever apply more pressure in the depths
of the whole than on the surface.  I would think no matter
how few the degrees of angle on the wedge the pressure is
still all going to be at the surface of the hole.  But the
array of long wedges, Trow and Holden makes them up to 4
feet long, as well as your  home forgeded smaller angles
as well  as perhaps the Japanese long rods all suggest
that it is possible to apply some amount of pressere
deeper in the hole.  I know that granite has a certain
amount of flexibility.  I have seen on line a carved coil
"sping" of granite which really does flex to the touch.
And there must be a certain amount of stretch to the stone
as generally a crack will appear on your w/s shims side
before it goes all the way through to the other side.

Very interesting to hear about your acutely angled wedges,

Bill