I get this fairly often. Being the stubborn sort, I generally ignore the first warning shot across the bow. To my regret.
I was carving a canoe bowl a while ago out of a nice chunk of yellow cedar. Had it nicely shaped, cut the model lines into it, did a rough sanding and started in on the hollowing. I use a drill press with a 3/4" Forstner bit to take the worst of the wood out of the way, but my drill press, being an ancient rebuilt thing I salvaged from a scrap heap, has no depth gauge, so I usually play around with the table elevation with the drill fully extended, using my forehead as a brake to keep the winding arm of the press fully extended while I set the table to the proper depth. Does that make any sense?
Anyway, my first warning all was not well was when I blinked hard at a bit of dust floating past my eyeball, the knob on the winding arm of the drill slipped from my forehead, whipped around and clonked me right between the eyes.
After blinking the stars from out of my eyes, I got up off the floor, and finished setting the depth. Flip the press "on", hold the work firmly in one hand, wind the press down and bore away. Ahhh, woodchips flying, the spicy aroma of yellow cedar, and the bit caught on a hidden pin-knot and whipped the wood around and smacked my knuckles a good one.
Does this boy learn his lesson? Hollow laugh!
A length of nylon cord wrapped and cinched about the bowl, holding it down to the table, and continue boring. Now for the last little bit to bore out, and I can finish up with a bent knife, except I seem to have mis-set the final depth and bored a hole right through the bottom.
Okay, I
finally got the message, dusted myself off and gave up for the day.
Go ahead, it's okay to laugh. I am.
