A few technical questions

[marks]

I would like to get some opinions on the following questions regarding wood thickness in various places on a pipe. I know the thinner the wood, the more risk you take in having problems, but how thin can I go without having long term problems on a pipe? I realize there may not be a consensus, or a single correct answer for any of my questions, but I would like some of your opinions. Thanks for the help!

Question 1. What is the minimum thickness of the walls of the bowl before you start risking burn out?

Question 2. Same as question 1, but specifically related to the bottom of the bowl. What is the minimum thickness recommended here?

Question 3. What is the minimum recommended thickness for the wood of the mortise walls at the end of the shank (I am using delrin for my tenons if that makes any difference)?

[KurtHuhn]

Question 1. What is the minimum thickness of the walls of the bowl before you start risking burn out?

That really depends on the briar. Different briar has different characteristics. I'm pretty sure there's no right answer, but I've seen the thickness of 3/16" tossed around as the minimum. I usually go 1/4" or more dependng on pipe shape.

Question 2. Same as question 1, but specifically related to the bottom of the bowl. What is the minimum thickness recommended here?

I'd say 1/4" here also. And, it is very important that the smoker build a good cake at the heel, as this area is rather prone to burnout. On my pipes, I normally go slightly thicker than the walls on the bottom of the pipes.

Question 3. What is the minimum recommended thickness for the wood of the mortise walls at the end of the shank (I am using delrin for my tenons if that makes any difference)?

That totally depends on your briar. If the briar is cross-grained, you'll find that the mortis is very brittle on the sides and prone to cracking. This is less of a concern if the grain runs straight along the shank. I always try to keep 1/8" at least, and sometimes even that isn't enough. This area is critical to the pipe because it's subjected to occasional sideways force from within as people remove the stems for cleaning and stuff. If the walls are too thin, the shank will crack, it's just a matter of when Of course, you need to balance that with aesthetics, and sometimes that not an easy thing to do.

One way to solve the problem of a thin shank is to use a bands. Another way, that generally has more of a "high grade" feel to it, is to use shank extensions. Almost anything can be a shank extension, and something very strong like bone or horn, or flexible like vulcanite or acrylic, can let you get away with thinner walls than you could normally get from briar alone.

[Tyler]

I must confess that I am not very techinical about this question. I am more intuitive. I look at a pipe, "measure" the thickness of the bowl between my thumb and forefinger, check out the mortise, and it either seems thick enough or it doesn't. In general, I think most of us do pipe making like a lot of other things we build, we over build the heck out of it in an effort to assure that it will not break. I am confident that I do.

I am often surprised by old estate pipes I find, usually of British make, and how thin the walls of the bowl and mortise are. Often these pipes have evidence of years of smoking with no apparent ill effect.

So, how's that for an answer that doesn't help?



Tyler

[marks]

Thanks for the insights!