Mortis bottoms

For discussion of the drilling and shaping of the stummel.
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LAH
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Mortis bottoms

Post by LAH »

I think I remember this being talked about a good while back, but can't seem to find it now. What are your guys thoughts of the bottom of the mortise. Are you guys for making a flat bottom mortise or just using a standard 118 degree drill bit. I understand that the least amount of extra air space the better. I've only smoked pipes the have angled bottoms, haven't had any problems with gurgling, turbulance, and what not. I'm just wondering if it's worth experimenting with or if it's just more of those fine details that some makers like to do.


Abe
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Sasquatch
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Re: Mortis bottoms

Post by Sasquatch »

Are you talking about just a straight pipe application or a heavy bend where you might find the airway wandering upward a bit?

At any rate, you are indeed talking about a miniscule amount of difference, not half a mm of deflection over the amount of diameter we are talking about here, so I doubt anyone thinks much about it. I know Rad leaves his tenons ragged and short by about 1/4" in all his pipes, but that's just cuz he's a dumb Merkan hillbilly.
ALL YOUR PIPE ARE BELONG TO US!
LAH
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Re: Mortis bottoms

Post by LAH »

I'm talking about using a flat bottom mortise on both straight and bent pipes.
The reason I bring this up, is at work we have a new drill, tool grinder that I've been learning to operate. I've also been reading up on drill point geometry and have been thinking about regrinding some of my drill bits to about a 160 degree drill point angle so I can have less airspace between the end of the tenon and mortis bottom. Probably won't do much for improving smokability, seeing as how some pipes I own have a huge gap between the mortise and tenon and seem to smoke fine.
Rads pipes smoke great so it must not make a difference. :lol:


Abe
wdteipen
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Re: Mortis bottoms

Post by wdteipen »

I used to think it made a difference but have changed my mind. It's easier to drill with a standard bit than a brad point. It was actually Rad's pipes that changed my mind. I own three with the bottom of the mortise angled with the bit and they smoke dry as a bone. If it makes any difference, it must be negligible and not worth the worry, IMHO. Use the drill bit your comfortable with.
Wayne Teipen
Teipen Handmade Briar Pipes
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oklahoma red
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Re: Mortis bottoms

Post by oklahoma red »

If you are striving for the perfect fit then just cut the end of the tenon to match the profile of the bit no matter what the angle. I use a straight chucking reamer for the final size of the mortise. These have a slight angle at the tip (which is the part that actually does the reaming). Simple matter to put a little bevel on the tip of the tenon to match that bevel.
I've purchased many pipes over the years with varying degrees of gaposis between the bottom of the mortise and the tip of the tenon and none of them turned out to be problematic. The secret here is to pull the stem off and clean the crap out every once in a while.
I mean absolutely no disrespect to any pipe maker out there but, IMHO, this falls into the same category as putting the deep funnel into the end of the of the stem's airway. IN THEORY,THE SCIENCE IS SOUND: no restrictions in the square millimeters of the airway. In practice, as long as the draw is not like trying suck a golf ball thru a garden hose, I question if the flat funnel is really worth the effort. To a degree, this is the "me too" syndrome. Someone at some point in time did this first. Then it became "well if so and so is doing it then it must be right and I'm going to do it too". Again, I cannot fault the theory but has anyone put one on a flow bench?
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Sasquatch
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Re: Mortis bottoms

Post by Sasquatch »

Actually, tapering the entire airway, from the tip of the tenon some final point of restriction near the button makes perfect sense from a fluid dynamics point of view. The flow gets faster the nearer you get to the restricted point, stays more laminar and is less likely to condense. So a perfect pipe on this theory starts with one diameter at the chamber, and a smaller diameter near the button - presumably with few or no widenings, gaps, or bumps.

I think the funneled tenon end offers a place for moisture to build up without gurgling - the place of greatest condensation due to flow variables is at that tenon/stummel airway junction.

There's more than one right way to treat the tenon end, whether you try to bottom it right out and make a seamless joint, or leave a little space and bevel the thing just a bit, or leave a huge space and make a Peterson system pipe.... and the fact is that without going to all kinds of weirdness, on a heavily bent pipe you are going to have some fudge factor on that.

I've built bent pipes that had tenons with holes in the sidewall, to match some funky drilling in the stummel - people said they smoked just fine. I've bevelled tenons severely, cut them crooked, opened them right up to 1/4"... they smoked fine.

Some of this we do because it's what smokers expect/demand, some we do because it just seems to work. As far as I can tell there's lots of right ways to do things, and as long as you keep in mind that the basic idea is to get smoke from chamber to button "in one piece", it's pretty easy to make a good smoker.
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TRS
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Re: Mortis bottoms

Post by TRS »

In my experience, the first pipes I made, with shallowly countersunk tenons, significant (1/16") gaps between mortise bottom and tenon end, and shallowly funneled slots all smoke a million times worse than the pipes I make now. Sometimes I use a precision Forstner for my mortise, but usually a standard drill bit. It doesn't seem to matter as long as i profile my tenon end accordingly. But a deeply funneled slot, almost zero gap and a well countersunk tenon end have dramatically improved the smoking qualities of the pipes I've made.
LAH
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Re: Mortis bottoms

Post by LAH »

Thanks for your thoughts guys. I believe I'll stick with want I've been doing for now. Maybe sometime in the future I might fool around with it, but from what you guys are saying and what I kinda expect is, I may be wasting my time.


Abe
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ToddJohnson
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Re: Mortis bottoms

Post by ToddJohnson »

Just note that, with any mortise, you need a verysmall gap between the face of the tenon and the mortise floor. If the tenon completely bottoms out in the mortise then what happens is that, when the pipe is smoked and condensation makes its way up the shank and soaks into the mortise floor, it will swell the wood, and push the tenon ever so slightly up the mortise resulting in a light gap between stem and shank. If some guy is using a micrometer and a set of calipers to examine one of your pipes, you should tell him to . . . um . . . kiss off!

TJ
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