On Sat, 4 Sep 2010 01:01:18 -0500, "woodstuff"
wrote:

"J. Clarke" wrote in message
...
7/8 Forstner, in drill press at lowest speed (350 RPM). Carbon steel.
Bit sharp (how do I know? Worked it over with a fine grit diamond file
las time I used it. This time I managed to slice myself taking it out
of the box--it didn't hurt until I saw the blood).

By the time it's maybe a quarter inch into the ash, much smoke. Tried a
piece of poplar and a piece of Douglas Fir, no smoke. Shavings coming
out are fine, continuous, hole is clean other than looking burned.
Continue on--cut a quarter inch, pull the bit out, repeat. By the time
I'm 3 inches in the bit is hot enough to burn me, overall yellow (not
just the edge, all the way up to the shank--not yellow-hot but the
straw-yellow discoloration you get when drawing the temper).

Does the same thing on the lathe at lowest RPM (500).

Drilled a dozen pieces 3 inches deep, drill continues to cut fine, so am
assuming that yellow is something coming out of the Ash and not
indicative of the bit losing temper.

Now, obvious thing to do is get a carbide bit for this job (it's going
to be continuing I hope). But was wondering if anybody had any other
sage advice.

I can sharpen pretty well, but I am thinking of the times when things didn't
get as sharp as I thought they were and were just dull enough to make a
difference. The sharpenss or dullness can usually be experimentally
determined by the volume of blood a cut on your finger produces :-)


It might be very sharp, but not a steep enough angle - or two wide a
cutting area.