Have tried fostner bits several times and on shorter holes they work but
build up to much heat. I have had charring in the holes when using fostner
bits even at low speeds, not often but a few times. With a hole of this
length (8") I have to make several passes or drill from both ends and the
fostner bits do not give as smooth of a shaft as the spade bits for this.
Main problem with the fostner bits is heat build up at depth which I seem to
have gotten anyway in this case.
"R. Pierce Butler" wrote in message
. 1...
"sweetsawdust" wrote in
:

Forget the dust collector the drill press is the villain here. To day
while drilling a 8" deep 1" hole with a spade bit at high speed in
oak, I had an explosion. I was about 3 1/2" deep into the hole when
with a loud bang and what appeared to be a flash, dust went all over the
shop. Blinded by a layer of sawdust covering my glasses and with the
taste of burned oak (maybe from oak dust landing in my pipe) I groped
for the off switch to the drill press. In shock I looked at my wood,
which was hanging from the drill bit and it looked fine with out my
glasses on, looked fine after I cleaned my glasses and set down for a
minute too. Found some ash and smell of "smoke" in the hole I was
drilling so it must have been a real dust explosion. So dust explosions
do happen but maybe not in dust collectors.




I think that your spade bit was spinning a bit too fast. Have you
considered
a forstner bit?