Bob La Londe wrote:
"Ed Huntress" wrote in message
...

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures does it take? How is the nozzle shaped internally? What
kind of thickness can you cut? What kind of volume of water does
it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the
actual cutting. I watched a demo of cutting 1/2" diameter holes
through a 4" block of Inconel, which was really quite impressive.
It took maybe 2 minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that
the early experiments, and some of the early commercial units, could
do some amazing cutting with water alone. In fact, I remember one
company that I reported on that sold the same model to a company that
was slicing Sarah Lee chocolate cakes and, in the building next door,
to one that cut cement-reinforced slag-fiber ("rock wool") insulation
panels.

You can cut steel with plain water, but it's very slow. I haven't
kept up but I think that all of the commercial units designed for
cutting metal now use abrasive grit. Still, the ability to cut with
plain water is a read head-shaker, IMO.

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to
expensive to have done. Granite is cheap. Cut granite is very
expensive. I was hoping to be able to make cuts up to 3-4 feet
thick. Looks like I either need a $50K machine or to spend the rest
of my life on one project. Neither is palatable so this idea will
have to pass for now.
Can you not use a wire saw something like used commercially. IIRC the
old ones, before diamond coated blades, used a soft metal wire, like
copper, and grit was fed into the cut and embedded into the soft blade
like a lap to cut the harder material. The blade is often a continuous
loop like a bandsaw. A program I saw showed that the Egyptians used the
process but the saw was a hand powered reciprocating saw.