On Dec 17, 4:00*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Ignoramus30138 fired this volley om:

I thought that it actually is abrasive and also clogs the coolant
pump.

both.

And the statement earlier that "most" woods don't contain much silica is
rife with problems. *As wood selections get cheaper, and more and more of
the scrap is salvaged, more bark, root, and knot sections get included in
plywood and press-board products, raising the silica content beyond what
you want on your nice tools.

LLoyd

Excellent point.

I have seen significant silica in solid wood...knots and bark injury
can cause sand to be anywhere in a wood product.

TMT