My own opinion is that the bit may have gotten dull, I had drilled several
holes with it since I last sharpened it. This could account for the slight
charring I found in the hole, but not enough to cause a fire ( no glowing
embers or any thing, just a dark "stain" on the wood) or maybe a foreign
object in the wood. What ever the cause was it was a first time in nearly
40+ years of playing with wood that I have ever had anything like this
happen. I have had steam explosions from using a dull bit at too high of a
speed and have brought up glowing embers from the same cause, but this was a
first. Just one of those odd events that was worth a passing on for
amusement and pondering. I will now go back to making a living drilling (
hopefully none exploding ) holes in wood.

For what it's worth I did have a live bee come out of a hole in a board I
was cutting the other day, but that is another story.
wrote in message
oups.com...

Oleg Lego wrote:
The Mark & Juanita entity posted thusly:

On Fri, 21 Jul 2006 23:28:25 -0500, "sweetsawdust"
wrote:

No dust, No screeching, Everything was going smoothly with no problems
and
then BANG it happened. I have performed this operation several times
with
no problems. This time was a bit different and exciting.

Is it possible there was something inside the wood you were drilling?
Some piece of metal or something else that, not so much causing an
explosion, but something that caught and caused a "kickback" so to
speak? I
know you indicate you smelled smoke and charring, but that is sometimes
normal with high speeds and/or dull bits in hard woods.

Something in the wood could also cause a spark. I used to see
occasional sparks from calcium inclusions when cutting teak. No idea
if oak can have the same, though.

Wood can grow around just about anything, including small stones,
grains of sand and so on.

I have to wonder if there wasn't something like a blasing cap (OK,
that would be too big but something like that) in the wood. A dust
explosion will not leave charred wood in the hole.

Here's a really wild hypothesis: Concentrated
NItric acid reacts with celluose to make an explosive (guncotton).
If somebody splashed a little nitric acid on the tree many years
ago then there might have been a little explosive spot in the wood.
I wonder, if you spilled ammonium nitrate fertilizer on a tree,
could it form an inclusion that would go bang fifty years later?

If you didn;t have a posting history, or this was April, I wouldn't
believe the story.

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