Why does this work sort of?

[dgerwin11]

Hi.

Impatience overtook me when I first got my drill press and I drilled two pipes with a regular, off the rack 3/4" S&D bit. This of course gave me a shallow v shaped bottom of the chamber. Both pipes smoke decently about 98%, but the very last of the tobacco does not burn. Not a whole lot of dottle. I think I'll keep smoking them and see if the cake will round out the bottom. Now that I have a PIMO 3/4" bit and that S&D ground to approximate contour, this will never be done again.

BTW, Sas, thanks for the heads up about this forum. Great repository of knowledge. Thanks everyone.

[frazeeg]

I would guess the last of the tobacco is wet from combustion but I'm sure the other more experienced guys would have a better idea. I usually don't smoke all the way to the draft hole anyway so that's never an issue for me...

I toyed around with doing the same thing with a standard drill bit before grinding a couple spade bits. Good to know it would have worked reasonably well

[Sasquatch]

I would guess that with the air being drawn through a small hole at the bottom, the tendency of the burn would be to head right for that spot, and if there's a wide area around that spot, probably the tobacco in the "corners" is unlikely to see heat.

[dgerwin11]

The operative phrase here is "worked reasonably well". It is the type of thing I could live with if I had to. But I don't have to, so I won't.