Well, I threw away one #30 high speed drill after only drilling one hole with it. I switched to a cobalt drill and I've now drilled 9 holes with it so far. A HF stepped drill also went into the trash.
After cleaning the pieces with denatured alcohol, I bonded a layer of heat insulation to each piece. The stuff is a woven textile fabric with a layer of aluminum on one side. It looks like tan fiberglass but it is "amorphous silica" fiber that is good to 1800F. The aluminum melts off well below that- it is just for heat reflection. I'll post a picture or two tomorrow.
Regards, Neil Tucson, AZ