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Not For Munchers

Somewhere, I read that half the value of an artisan pipe lies in the hand cut stem. Even if that’s off by some substantial percent, it still makes the stem a worthwhile subject for a “deep dive,” as they say on YouTube.

Among pipe collectors and experienced pipe smokers — and discussing the line between someone who “collects” pipes and someone who simply has been smoking pipes for 40 years and has a bunch of nice ones might be its own post — there is appreciation for a hand cut stem.

What’s the big deal?

A hand cut stem is most obvious when it is part of a pipe that is conceived and carved as a whole, from rim to button. As with just about anything humans make and use, there is a distinction to be made between utilitarian pipes that, while perhaps handsome, are essentially functional (say, Falcons), and pipes that, while more or less functional, are primarily sculptures in a highly restricted medium. This distinction, of course, lies on a continuum.

It reminds me of one of my favorite stories that I read in an in-flight magazine on my way to New Zealand; the female author had gone on a pub crawl in London, and was writing about the atmosphere and clientele of the various pubs. At one pub, she learned from the bartender drawing a pint that when he sloshed off the foamy head, the discarded beer ran from the tray under the taps through a hose to a bucket under the bar. The contents of the bucket, a flat admixture of all the beers on tap, was called “wash” and sold for 5p a glass.

Faintly horrified, the author asked, “But how does it taste?” Replied the bartender, “You’re missin’ the point, Luv.”

At one end of the continuum, there are pipes so conceptual and intricate that to ask how they smoke is missing the point, and at the other, pipes so utilitarian and inexpensive that nobody asks why they aren’t prettier. Today’s artisan pipe generally lies somewhere in between, at a point where it is expected to smoke very, very well, and also please its owner visually. So a stem that is incorporated seamlessly into the lines of the pipe gains points for obvious handcraftedness.

I’ll offer one of my own pipes as an example because, well, I don’t have the rights to any photos of Tokutomis. I know I’ve shown the Clam in previous posts, but here we’re pretty close to abandoning practicality for the sake of visual effect. I’ve called the flip stem the stiletto heel of pipes before, and while one might be missing the point to ask why women wear such an impractical and even injurious shoe, let’s take that approach to the Clam‘s stem.

Its fit is unforgiving, either perfectly aligned, or misaligned. This is somewhat true of any pipe that does not have either a floc or a perfectly concentric and cylindrical stem and shank junction, but the swoops and fins at this junction on a pipe like the Clam make alignment critical. If the stem isn’t perfectly aligned you can see it from space, and misalignment makes the sharp exposed corners vulnerable. It makes me nervous, knowing I’ve sent those fragile corners out into the world, but the demand exists for the visual effect, and while makers of stiletto heels may have misgivings about all the achilles tendons being shortened and toes being crushed, what are they going to do?

Also, it would be difficult to replace. Believe it or not, something I often consider is what would happen if I (or someone else) needed to replace the stem on one of my pipes. On most of them it would be pretty easy. The Clam, not so much, and I guess that takes us back to our continuum. If you bash in a fender on a Toyota Corolla, replacements are available. Replacing a fender on a 1930 Duesenberg would take some craftsmanship.

Oddly enough, I've never had a pipe come back for a replacement stem, never even had an inquiry. Although, somebody once sent me a link to an online auction of one of my pipes, saying "This doesn't look like your stem." Sure enough, the stem was a replacement; the material was a nasty yellow acrylic I've never used, the button was nothing like mine, the fit to the shank was poor. When I sent the seller a message to say that the stem was a replacement and not my work, he replied that I was wrong. Wait, what? Anyway, maybe when somebody chews through a stem he's embarrassed, maybe he figures the maker will charge too much, who knows. But really, if you need a stem on a pipe I made, check with me before you send it to anybody else. Other than George Dibos — actually, what was I thinking, call him FIRST.

Fortunately, pipes like the Clam are trailer queens and their owners know what they’re doing; the point of discussion here is to stake out the sculptural end of the continuum where stems are hand cut because that’s the only way to make a pipe like that. Moving toward the middle of the continuum, we find a great number of pipes with stems that could possibly be molded, but are made by hand from hard rubber rod. Why is that important? I mean, why don’t we just take molded blanks that are sort of close to what we want and shape them by hand the rest of the way? Why waste 80% of a rod when we could waste 20% of a chunky blank?

First, the material. Most of what I know about hard rubber comes from clarinet mouthpieces, and in that realm I probably care much more about material quality than any pipe smoker. The best clarinet mouthpieces are machined from hard rubber rod, period. Rubber is just one word for a bewildering jungle of natural and synthetic stock, processing methods, fineness of grind, colorants, additives, plasticizers, UV protectants, sulphur content, vulcanization time and temperature, and so on ad infinitum. Why is the material in molded pipe stems less satisfactory?

Partly because of money, partly because of the limitations of the process. If you’re making one pipe that costs hundreds of dollars, it would be foolish to quibble over a few extra dollars for stem material. On the other hand, if you're making thousands of pipes that retail for $30, you count every penny that goes into a stem. While it is possible to specify a higher quality rubber for molded items (and some ARE better than others), the cost savings of molding lots of identical things instead of machining them from solid is the best reason for molding in the first place, and if you’re going to save money by molding, might as well save a little more on material. Ergo, the cheap molded stem with its low lustre and quick oxidation is the standard for cheap pipes.

Beyond that, the complexity of the part to be molded has some bearing on the material used, so even the best molded stems can only be so good. Rubber for a complex molded part must be able to flow into and release from the mold, which places some limitations on its recipe, while rubber compressed into simple cylindrical molds for rods has fewer such limitations. I don’t think rubber companies even bother making lower grades of rod. If you’re using rod rubber for pipe stems, or fountain pens, or woodwind mouthpieces, you only want the best. My belief is that stems cut from this rod take a higher polish and oxidize more slowly than molded stems. And are more comfortable in the teeth, but that one is a rather fine, subjective point.

Some will be asking, what about acrylic stems? Why are we dealing with rubber and oxidation at all? Well, if you want acrylic stems, they’re out there. I used to make the occasional hand cut acrylic stem, but no longer. Acrylic makes a lovely molded stem but is hellish stuff to work by hand. It stinks, it gives me a headache and is hard on my files. And pipe smokers are somewhat divided. Some love the feel or the permanent shine of acrylic, others hate the harder feel, shine be damned.

There are other stem materials, of course; humans will try anything. State of the art in Victorian times was natural amber, as featured in the Sherlock Holmes story The Yellow Face. Fragile, rare, beautiful. Bakelite makes a nice stem except for the fact that it’s a scarce vintage material and very expensive. It’s also not as tough as rubber. Some factory pipes have had molded nylon mouthpieces which are soft and quite tough, but don’t polish well. I’ve made one pipe with a horn stem and I guess as a stem material it’s not as impractical as it might seem but finding a suitable piece is very difficult. I’ve seen briar stems, talk about fragile. Even with oxidation and not being indestructible, hard rubber is pretty much our best option.

Finally, we’ve arrived at the point where we’re holding a piece of hard rubber rod and want to make a stem out of it. It’s a regular stem, say, a Danish-style saddle stem.

First choice: what kind of tenon, integral or Delrin? I don’t know who started using Delrin for briar pipes; it seems they were a fairly new development when I started in the late 90s. I think the Delrin tenon originated with meerschaum pipes as an improvement over bone, though much thinner and typically white, probably to mimic bone. Anyway what kind of tenon and why?

It depends on the pipe, and, to some extent, on the customer.. There are those who think that a high grade stem has a machined tenon, that this machining is part of the skill that goes into the high grade pipe and that a Delrin tenon is a cheap trick for those who can’t turn a tenon. Others think that Delrin is such a superior material that anyone making a rubber tenon is living in the past. Still others acknowledge the material qualities of Delrin but worry that it is TOO strong, making the cost of a sat-upon pipe a snapped shank rather than a broken tenon.

Fortunately, most of you don’t care much one way or the other, which is, I think, appropriate. A Delrin tenon is functionally superior and I will use one when possible, but I’m not wedded to it. Delrin, the trade name for acetal resin rod, is very strong, very low-friction and highly wear-resistant. When I send out a pipe with a Delrin tenon I have virtually no concern that it will get stuck or become loose. While the connection between Delrin and rubber could possibly fail, that would be an easy fix if it did happen, and so far the benefits have outweighed the risks. However, if I want to make a really shallow saddle, there isn’t room for a socket to fit Delrin into the rubber, and if I want to make a tenon in an odd size — say, larger for a bent pipe — it’s usually a better fit to turn the tenon.

That brings in the matter of tenon size. In choosing tenon size, there are two competing goods. It is good to preserve as much briar thickness in the shank as possible. It is also good for the tenon to have a large diameter for gripping surface area. A larger surface area permits a secure fit with less friction, and so a larger window for seasonal contraction and expansion without the stem getting stuck or dropping the stummel into your lap. A thinner shank will require a smaller diameter tenon, the extremity being the 3/16” stainless tubing used for bamboo and spaghetti shank pipes. Thinner tenons must be longer to afford enough surface area for grip, thicker tenons can be shorter. A thicker shank permits a larger tenon. A deeply bent pipe will require a relatively large and relatively short tenon to permit the necessary drilling angle, requiring a relatively thick shank. It’s all relative.

There are some tricks to turning a smooth, glassy finish on hard rubber. First, the lathe tool is extremely finicky. It’s got to be RAZOR sharp or it will just grind and make dust and leave a rough finish. I grind high speed tools instead of using carbide inserts because I haven’t found a carbide insert that will give me the finish I want, and if you have to sand a tenon to fit, now you ARE talking about a lot of time.

I have a tool ground specifically for tenons, with a good nose radius (you don’t want a sharp inside corner at the base of the tenon, that creates a stress riser and a weak point), and I seem to have to sharpen it every time I use it. Theoretically, a lot of positive rake should be better for soft materials but I’ve found that a neutral tool, exactly on center, works best for me. Rubber’s springiness makes vibration and chatter a potentially catastrophic problem, While positive rake does cut efficiently when the rubber is stable, if vibration starts, a positive rake tool grabs and now you have a situation. Neutral rake stays smoother longer.

I’ve also learned to polish stuff on the lathe whenever possible.

One more task on the lathe, trimming the tenon to length. The flush fit tenon is a major distinguishing factor between artisan and factory pipes. The latter's frequent gap between the end of the tenon and the floor of the mortise receives blame, mostly justifiable, for gurgles. I discussed how factory pipes often use a considerable gap to facilitate a curved shank in a previous post, The Bends. For straight pipes, it’s a matter of manufacturing tolerance. If you’re making pipes in a factory, parts must be interchangeable; all mortises must be deep enough and all tenons must be short enough that the latter will never bottom out in the former, requiring additional work. So the allowable tolerance will be . . . something. If you’re making pipes one at a time you might as well get it spot on. I don’t know how others do it, but I measure the mortise and allow an extra .010” when cutting the tenon, then sneak up on a perfect flush fit. If you can see dust from the mortise floor on the end of the tenon and/or a sliver of light between the stem and the shank, take another couple thou.

Ok, we’ve turned the tenon and whatever other features are to be turned. And drilled and funneled the air hole, which I covered in a previous post about the airway. Now, the task is to remove everything that doesn’t look like a stem. I know many makers do a lot of stem shaping on the wheel. I probably do less shaping on a wheel than most makers in general, and I find I can remove rubber almost as fast with a patternmaker’s rasp as with a wheel, and with less mess.

From the rasp, I go to files, and then to sandpaper and/or emery boards. I’ve always said that a professional cuts close to the line with a rough tool, and I strive to leave a rasp finish that doesn’t require a lot of filing, and leave a filed finish that doesn’t require a lot of sanding, and so forth. It is really annoying to buff a stem and find a scratch left over from 220 grit because I was impatient at 400 grit. I finally wet sand at 800 grit or so. Sometimes finer, I’m always going back and forth on exactly where the point of diminishing returns is when it comes to sanding versus buffing. I do use a scraping knife, but more as needed than as a staple, which may mean that I have the wrong tool or have never learned to use it properly. Anyway, this whole shaping and smoothing process, ideally, leaves a smooth, ripple-free, mirror finish.

Of course, the mirror finish doesn’t happen without buffing, but I don’t know how much patience you have left to read about it. Generally, the better your sanding, the better your buffing, but it’s certainly easy enough to take a pipe that’s almost done and push too hard and buff a groove or ripple into the stem. I use two different compounds, each with its own wheel, a red medium compound and a white polishing compound.

Another consideration is comfort in the teeth, determined by contour and thinness. Thinner is generally considered more comfortable, but thinner is also less durable. I remember how Peter Heeschen said on his website that his stems were “not for munchers.” I cut the airway first and make it flow easily; I reckon it doesn’t matter how thin the stem is if the air (or a pipe cleaner) can’t get though. Then I file the bit to what I consider a prudent wall thickness. For me, .040” is the dividing line and I’ll take a few thou either way. Finishing will remove three or four thousandths. For reference, a sheet of printer paper is about three and a half thousandths, or .0035“. Much thinner and the bit feels flimsy, much thicker and the bit loses its just-right feel in the teeth. I could go thicker for someone who wants to chew on a stem, or thinner for someone who is willing to be careful, but my stems usually finish out at 3.8mm or a little less. 3.5mm is about the practical limit without compromising on airway flow.

The stem terminates in the button, which is essential to keep the stem in your teeth, but otherwise is a matter of the maker’s style and the customer’s preference. My own preference is for a reasonably prominent button so I make my pipes that way, reasoning that I can always make a button smaller. I like a button to look crisp but feel comfortable.

For bent pipes, the stem is heated until it is plastic and held in the desired position until it cools. For a heat source, I use the same hot air gun that I used for straightening the nodes for bamboo fly rods. Others use alcohol lamps. I think I read about one factory with a box of heated sand into which stems are inserted and left for a period of time. That would be nice, and practical if I were bending dozens of stems a day. For a few pipes a week, I’ll stick with the heat gun. As an aside, this is another area where rubber is ideal, maintaining its spring to form an even curve as it is heated, while acrylic is miserable, staying rigid until it reaches a specific temperature, at which point it is soft as overcooked spaghetti with no spring whatsoever. Two degrees hotter and it melts.

Pipe cleaners are inserted to keep the airway from flattening as the stem is bent.

Because heat from bending dulls the shine, I don’t worry too much about final polish until after the stem is bent. Sometimes the contour even needs a bit of a nip and tuck after bending. So, while the stem is easiest to sand and polish when it’s straight, it’s no surprise if I have to go back to 800 grit to fix something after it‘s bent. Final buffing takes a while, and it could take forever if I let it. Basically, once the pipe is sold and stamped and ready to mail, I stand at the buffer and obsess until I can’t take it for one single blasted second longer. Then I drop the pipe in the bag, pull the drawstrings, and the next person to see it is the customer. Or maybe the customs agent.

The end.

If you have questions, feel free to leave them in the comments. I have heard that the comment login process can be frustrating and I’ve been working on it with Wix support. Here’s what I have found: if you are running Safari on an Apple device, you must be logged in before you start typing your comment. If you type before logging in, when you hit “publish” you will be asked to log in, and when you do your text will be deleted. Chrome seems to work fine. Wix support says they can’t recreate the issue. You also need to be careful, if you are already a member, to use the “log in” link instead of typing your username and password in the “sign up” field that is presented first whether you are a member or not. Oh, yeah, there also seems to be no indication on the blog page whether you're logged in or not. Only an issue for the Safari/Apple folks, but seems like a pretty basic feature that's missing. Sorry. Like I said, I’m working on it.

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