354. Smoke Channel Mods for a 2023 SPD D20 + Last Call for Pocket Jars

At Portillo’s, that restaurant-of-restaurants, that Hot Dog Stand of Paradise and de rigueur eatery for generations of Chicagoland Pipe Show attendees, fellow CPG Gary Hamilton and I recently met in north Texas to discuss pipes, pipes and pipes. Fortunately for us, Portillo’s understands how crucial it is to have a satellite branch for Pete Geeks west of the Mississippi. We sat in a booth almost under the photo of a pipe-smoking guy. That’s right, there’s a huge photo of a guy smoking his pipe while repairing a boot sole in the Texas branch of Portillo’s.

Count down 4 signs from the top right. Guy working on boot sole. Didn’t think to photograph it while we were there.

As per usual, we removed several pipes from our bags pertinent to the discussion. For myself, I needed advice on my 2023 SPD D20. I adore this shape as I’ve said too many times, and while I companion the 2016 POY version, when the SPD came along . . . well, you know how “PPAD” (Peterson Pipe Addiction Disorder) is—and with the tricolor ring, I couldn’t say no.

The problem, as I told Gary, is that the SPD doesn’t seem to be smoking as well as the POY. Normally when this happens, if I can’t figure out a solution, I pass the pipe along to someone who hopefully will have a better experience with it. But I want to keep this one, not as a collection piece (I’m not really a collector) but as a rotation pipe. To me it’s important in the shape chart because it grows organically in the soil of the Peterson house style, achieving the rare feat of being strikingly contemporary and distinctively Irish while providing clear ques to its ancestry in its muscular shank and straight-sided stack chamber.

The SPD 2023 (top) and LE 2016 (bottom) D20s.
Notice the slight difference in the stem shoulders.

So Gary took a look. Same chamber size, same diameter of smoke channel in the stummel, same basic stem as the original. But the POY has a chamfered tenon and a deeper-channeled button: maybe, Gary said, all I needed to do to bring the SPD’s performance up to the POY’s was to address these issues.

We both agreed there could be one more problem that is always a consideration when dealing with same-shaped pipes: the briar. That’s in the hands of Mother Nature and the good people who harvest and cure the briar, which is why an inexpensive pipe sometimes smokes as good or better than one costing a lot more. If it’s the briar, or if these mods make the smoke channel too open, I won’t have achieved a thing but done the pipe a disservice. Ah well. Choices have consequences and the life of a pipeman can be hard at times!


Opening the Smoke Channel.

I’ve posted about this process too recently to make much of it here, but I wanted to at least document the difference between the two D20 stems.

The SPD’s vent is easily observable. While channeled, it’s quite shallow.

When I got home, the first obstacle was in getting a sense of what the smoke channels in the two buttons actually looks like. I could get good photos of the SPD’s because it’s only 2.5mm deep. The POY’s channel I measured at 5.3mm. For whatever reason, I couldn’t get adequate light to photograph the POY until I thought about blowing some white powder into it. I blew through the channel to create some humidity, then dipped it in gum Arabic (the bowl-coating stuff). It gets sticky and adheres, unlike flour or talc which just clog the opening. It helped me see that the POY’s channel is indeed much more open side-to-side in its v-slot as well as going that extra depth:

The POY’s smoke vent. These photos don’t really do justice to what I could see with my loupe under the light, but I hope you can get an idea of the difference between it and the SPD. The white stuff is Arabic gum powder, blown in to let me photograph it.

(Chasing A Rabbit.  While I’m thinking of it, one of the things I love about the hobby is photography and being able to share photos with other PGs. For most of my work I use a Canon 90D and a 100mm Canon lens with macro. But for some really close work, I often just use my iPhone 11 Pro, especially if getting the color isn’t super important.  What I need is some kind of super high intensity jewel spot that I can mount so as to have hands free to manipulate the camera. Do you have any advice, fellow pipe photographers?)

The slot-opening process is fairly straight-forward, inexpensive and well within the skill-set of most. As I illustrated in Post #345,sandpaper, Micromesh pads, a needle file and slot funneling tool are all that’s needed. I again blew some Arabic gum powder into the slot to create enough reflection so you could see the finished result:


Tenon Chamfering the SPD.

Before going quickly through the tenon chamfering–something else I’ve talked about of late–I wanted you to see the SPD mortise is stepped-down, once for the tenon, then a second time about two-thirds the way in, making it 26.3mm to the airway entry.  The tenon is 14.3mm, making a tenon-mortise gap of 12mm. I couldn’t get a good photo of the POY mortise, which is quite dark by now, but by comparison with the SPD, the POY’s mortise is not stepped down, with a mortise depth of 27mm and tenon of 13.5, leaving a tenon-mortise gap of 13.5mm. Is this important? Who knows. But it’s fun and that’s what matters in Pete Geekery.

The POY’s mortise is now too dark for me to get a good photo. It’s “wide open,” whereas the SPD’s shown above has two steps (the bottom “step” is really the wall where the air hole is drilled).

So getting down to business, take a look at the difference between to the two tenons so you can see my plan of action:

The top photo gives a side detail (silver P  = POY and gold = SPD). The second shows the tenon ends. Notice the SPD  is a little longer. The third photo shows that the beveled rim of the SPD is where the extra length occurs. The bottom photo shows the chamfering of each, the POY on the left and SPD on the right.

So what I wanted to do was replicate the POY tenon, which means flattening the bevel end of the SPD then chamfering it as nearly as possible to what I see in the POY chamfer.

I got real brainy (for me) and thought to use a sanding pad on my Foredom lathe. Making sure the end of the tenon was perpendicular, I used fairly low RPMs and reduced the length in far less time and with less effort than I would have by hand.

Next came the chamfering with the two smallest countersink bits:

I honestly don’t think K&P used to do anything beyond the countersinking, which doesn’t actually feel as rough as it looks in the photo above. Afterwards comes a bit of tricky work, learning to fold the various grits of sandpaper into shapes that will fit into the channel. I’ve discovered some flexible sandpaper (the 150 grit is the top photo below) that I love, but I’m so much more interested in spending my shekels on pipes than tools that I haven’t invested in what I should.

The 2nd through 4th photos above show working up the grits from 150 to about 1200, I think. I applied mineral oil on some of the paper-backed sandpapers like the 220 seen above, which helps.  At some point I really need to invest in Micromesh papers up to 12K, as the pads will not readily bend to do this type of work.

So here it is, finished. It’s not mirror-smoothed, as you can see, but I figure the radial lines will help those air molecules along well enough, and certainly more than the original POY’s chamfer.

Comparing the smoking experience of the modified SPD with the original POY, the SPD is just a bit more open now than the POY. I’m not a fan of the open airways Rick Newcombe advocates. I’m used to the System’s much harder air drag and while I do smoke some fishtails, Rick’s open door policy burns my tongue.  So I’m cautious not to be watching a movie while I smoke the SPD but reading or simply meditating. In those activities I can control my sipping. Final result: I’m happy to report the pipe does in fact smoke significantly better than before, with much less turbulence.


Thanks to Gary Hamilton, CPG, for advice and discussion




There’s been a number of additional requests for Pocket Jars, so here’s one last chance to get yours
or get a few more.
You MUST fill out this Google Form.
We’ll take orders until next Sunday, 9pm CDT.

Many thanks to all who participated in the Summer Event,
and to Marie Irwin for managing the supply chain, shipping, invoices and
all the other hard stuff.


Tom Cuffe, CPG


Prof. John Schantz, CPG


John Young, CPG


James Bourgault, CPG


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Michael Sparks, CPG

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