cutting sandstone

Quoted text begins.how long the diamond blades last
End of quote.

Hi Greg,

This is a fairly open question, and the answer depends on the type of sandstone
you are planning to cut (it's really a grinding action, but everyone uses the
term 'cutting'). If it is fine grained (0.2-0.5mm), then there will be less wear
on the blade than medium or coarse grained sandstone (0.5-2mm). The type of
minerals that make up the stone, and the way the particles are bonded together
are important too.

The diamonds in a saw blade will last longest if they are kept cool, as well as
being well-supported by the metal matrix. You need to have the best cooling and
lubricating method (i.e. jets of clean water aimed directly at the cutting zone)
so that, firstly, the diamonds don't overheat and fracture, and, secondly, to
flush the abrasive slurry away from the metal matrix holding the diamonds in
place. More info here: http://www.mkdiamond.com/home/tec_blade.html

It is also important to consider the hardness of the metal matrix - the rule of
thumb is non-abrasive stone: soft matrix; abrasive stone: hard matrix.

This means that non-abrasive stones like limestones and marbles don't wear the
matrix very much, so the diamonds easily stand proud of the tool surface, ready
for grinding. Abrasive stones like granites, sandstones and concrete need a hard
matrix so the diamonds don't fall out. Think of peridontal disease:
http://www.perio.org/consumer/2a.html and compare it to diamonds in a metal
matrix (scroll down for the picture):
http://www.diamant-boart.com/stone.cfm?language=En&page=DT

There is technology other than band sawing to consider, such as wire sawing:
http://www.diamant-boart.com/stone.cfm?language=En&page=Tools1 and abrasive
waterjet cutting: http://www.flowcorp.com/

You may also need to think about the effect that a diamond-tipped bandsaw blade
will have on the bandsaw pulleys, and what will happen to the moving parts that
get coated with abrasive slurry.

Simon