diamond blades

["sculptin g" <sculptin@zzzzzzzzzzz>]

Regarding recent comments about diamond blades.

I have been using a brazed diamond blade (sometimes referred to as vacuum
brazed) and it is amazing. This is a relatively new technology compared to
sintering or electroplating techniques which have been around for a long
time.  For those not familiar, the two the basic differences are:

Electroplated: Diamonds are electroplated onto the outside surface (imagine
a donut dipped in sugar). Electroplating is done with a liquid solution
using electricity. Advantages - fast cutting on soft stones because many
diamonds are exposed. Disadvantages - quick wear, especially on hard stones,
or soft stones with impurity.

Sintered: Diamonds are mixed with a powder which is then baked to make a
solid segment (imagine rasins or chocolate chips in a cookie). This is a hot
process where the sintered tool is baked at very high temperature to
"sinter" the metal powder and diamonds into a solid mass. Advantages - long
lasting, especially on harder stones. Disadvantages - Diamond exposure is
lower, so cutting is slower, and on some soft stones can be frustratingly
inefficient.  Also, a certain abrasiveness is required to wear down the
metal segments and expose new and fresh diamonds to keep cutting efficiency,
something that doesn't happen with a softer stones like marble, therefore
cutting efficiency is not there. When cutting softer stones a sintered tool
can be "sharpened" periodically by doing a few passes on a very abrasive
material eg. sandstone, or old carbide wheel.

This brings us to brazed blades. I am not sure of the technique, but I think
that it is a hot process that solders the diamond segments onto the tool
blank. As the name implies, this is probably done in a vacuum, maybe to keep
the molten metal flowing, or possibly to keep the diamonds applied to the
tool blank... I don't know. The result is a tool similar to electroplated
with the diamonds exposed on the outside (advantage fast and efficient
cutting) with a very strong bond similar to brazed (advantage long life).
Promotional literature states that life of a brazed blade is about 5-10
times that of an electroplated (by my use so far it appears to be true).
Price paid is similar to or not too much more to electroplated. I have also
seen companies promoting use of brazed tools on granite, but I am not sure
of how long it would last as my experience is only with marble and
pyrophyllite. Of course it still may be worth it to use a tool that lasts
half as long, if the cutting efficiency is double or triple. Brazed products
are available in cup wheels, blades, burrs, files, etc in all types of tools
that are available in sintered and electroplated.

Brazed carbide tools are also available in very large grits that would be
prohibitive in large grits of diamond. These are great for quick removal on
soft stones, but would not stand up to very hard stones.

Price for a brazed 5" flush mount cut and grind blade (has diamond on side
and on face) about $60-70.

By the way if you do not have a flush mount blade that is another absolute
must have, but thats another story.....

Happy sculpting