From: mulligan@advinc.com
Newsgroups: rec.crafts.metalworking
Subject: Tooling for fiberglass (was amaZing feet)
Date: Sat, 18 Sep 1999 14:45:30 GMT

In article <37E2ECCA.D83FA554@apt2.sao.arizona.edu>,
  boyd@pegasus.la.asu.edu wrote:

> No doubt there is a better way. My mill isn't CNC.  Suggestions?
> Also what kind of steel tools hold up best when cutting these
> materials?

Glass-reinforced resin tends to really eat tooling alive - I
would not bother trying to use HSS but would lean towards
carbide.  The problem even with carbide tooling is that the
glass whiskers tend to pick out the cobalt binder in a carbide
tool.  Carbide tools are sintered out of particles of silicon
carbide mixed with cobalt metal as a binder.  The SiC is hard,
the cobalt is soft.  So when it erodes away, the tool edge
dulls - the hard bits of SiC get torn out of the edge.

My favorite for doing fiberglass is Polycrystaline Diamond.
Not that expensive, and about 100 times the life of carbide
tooling. There are other very hard, very tough materials out
there as well - you might consider investigating CBN or cermets
as well.

Jim