260. A DIY on Bare Chambers & Precarbs

Juan Delacroix likes to say that “God leads every pipeman by a different path,” and in that spirit I thought I’d share a few DIY thoughts. The first, from Prof. John Schantz, CPG on how to create a bare chamber in a new K&P that has the “new” bowl coating; the second, an update on how you can replicate K&P’s pre-carb bowl coating for yourself.


A bare chamber can be a dangerous thing, leading to scorch marks, spider webbing and (shudder) even burn outs. That’s why virtually no pipe maker offers one. They’d rather provide the insurance of a precarb or glass-impregnated and impenetrable bowl coating, which keeps them from economic loss and a bad name and the pipe smoker from anger and frustration.


For those with a taste for adventure and pipe nirvana—and I am not recommending you try this for yourself so please don’t send me hate mail—there is a special bliss that that can be experienced when breaking in a pipe with a bare chamber, a heavenly taste and otherworldly smoke. I suspect it has to do with the nothingness of everything, but that’s a theological (or philosophical) discussion best left for another time. I can only testify—along with Prof. John, who is the True Believer here, that when I’m up for the thrill of it, it’s amazing, if also a bit dangerous. It doesn’t last forever, but the strange thing is, that a pipe broken in with a bare chamber just seems to smoke better and better with repeated use.

John makes everything look easy. This is his 4AB with the precarb removed.


The big danger factor comes in the fact that I’m not nearly as self-aware as I ought to be when breaking in a new pipe. I get all excited about the process, promise to retard my cadence, slow down and concentrate on sipping through the first few bowls. But it’s me that tends to be retarded, as I forget what I’m doing, get caught up in the book I’m reading or movie I’m watching (even worse), and before I know it I’m chuffing away as per normal and look up to ask my wife if she smells something burning.

A second danger factor concerns those who, like myself, adore virginias and va/pers. With their rich sugar content, these tobaccos burn hotter than aros or English mixtures, and as the ember of tobacco burns down, can cause some hot times that are best avoided.


The pipe I’m working with today is one of my favorites, the Rathbone from the SH Return series, in the (for me) drop-dead gorgeous and wonderful-to-hold new rustication as featured in the 2021 Christmas pipe. I’ll turn this over to Prof. Schantz:


  1. If it is the new water based coating, I just use a 1/2 sheet paper towel and fold it and twist it to chamber size.

  1. Then I run it under some hot tap water and squeeze out the excess. If your tap water isn’t almost as hot as you can stand, you might try heating water on the stove, as the heat of the water greatly helps the process.

The “before” shot

  1. I have learned to be careful about not getting any water on the outside or even on the rim if I can help it.
  2. I corkscrew the damp towel around a few times, then follow it with a dry towel and repeat the process until I am satisfied that no more bowl coating is coming out.

After a first wipe. Notice I managed to pick up some stain. Not from the bowl rim, as you can see, but underneath the precarb.

After 4 or 5 wipe-downs, there are still some dark patches along the upper half of the chamber, a combination of pre-carb and vestigial stain.

  1. I finish with a lightly damp alcohol towel and may even carefully touch fire to the inside of the chamber to burn off the alcohol and dry out the briar some. I want as small an amount of water soaking into the briar as possible.
  2. If there are still some stain patches, I may wipe them out using Everclear, 100 proof Bourbon, 91% isopropyl alcohol, whatever is handy.

Scrubbing with an isopropyl-damped cotton pad removed much of the remaining stain in the chamber. It also removed the stain around the inner bevel! John warned me about this.

I understand Mark had some difficulty (no surprises there!) and resorted to 150 grit sandpaper. Sometimes I have to do this myself. He says working the sandpaper on the dowel (pencil) up and down is a beginning, although the paper seemed to remove more stain with a side to side sanding action.

I like to wrap 150 grit around the eraser-end of a pencil, taping it securely. I sanded up and down at first, but found that side-to-side took off more stain.

Mark: Having cleaned the chamber to the best of my patience, I thought I might use Orlik GS for the first smoke, because it’s a virginia (which many pipemen use to break in a pipe), because it’s a cool-smoking virginia (I think it’s a va/bur, although many will disagree) and because to my palette, it’s an extremely subtle tobacco, one with flavors that only fully emerge in one or two pipes in my rotation. I gave myself the Self-Awareness While Smoking award this time, sipping slowly and letting the pipe go out every five to seven minutes to cool off a bit before relighting. The Rathbone is what I call “Peterson Stack” with a chamber height of 49mm, so I enjoyed a full evening’s smoke and managed to quit before getting near the air hole. I wanted not to smoke it to the bottom the first few times, as a bare chamber can sometimes burn at the air hole.

This is the completed project, including the restained inner bevel. 90% of the stain has been removed and all the precarb. For the bevel, I applied full-strength Fiebings dark brown on the tip of a Q-Tip, wiping away excess.

John: With bare chambers, I take a 4mm drill bit and hand turn it along the upper half to third of the air hole in the chamber. What this does for bent pipes is eliminate the thin wedge of wood there that is highly susceptible to heat, creating a tiny shelf. It doesn’t need to be much, just enough to combat the heat while breaking the pipe in.

Mark: Not having the thingummy-tool (John told me what it was) that you insert the drill bit into for hand turning, I resorted to my slot file (a very sharp, tiny round file used for the air hole at the button end of the stem). I could just work it with enough light and magnification to do the job with control.



All the effort of creating the bare chamber turned out to be fully worth it. I will use this method again and may in time become as devoted to bare chambers as John.

K&P fishtails don’t always play friendly when I smoke virginia tobacco, but this was one smooth ride. I’ll think it’s because of those bare chambers (which really do taste different than anything you’ve ever tried, I promise you). It could, of course, have something to do with the wood, the chamfered tenon, the improved acyrlic button and just the joy of still being alive. I prefer, however, to attribute it to the bare chambers & have designated my Rathbone Christmas Rustic an Orlik pipe.






The word is slowly getting out that the precarb bowl coating K&P uses is absolutely fantastic, offering a pleasant, neutral flavor and quick break-in time. Unlike every artisan pipe maker and most factory pipe makers, K&P has revealed the formula, which is a combination of food-grade gum arabic and activated charcoal powder (this latter is used orally by many folks to clean teeth, etc).

Last April I wrote about my attempts to recreate the formula and the many reasons why I thought it might be useful. While it isn’t a replacement for pipe mud as a chamber-floor filler and a corrective for burnouts and spidering, it is perfect for use on vintage, estate and NOS pipes. Every NOS pipe before 2018 will either have a vegetable-base paint or (before the early 1990s) stain.

After sanding out the stain or paint, the precarb offers a safe and pleasant way to break in a pipe. I sometimes get anxious when first smoking pipes like the 1309 NOS pictured in the banner, because I know that bowl was cut 80 years ago and I don’t want any kind of excitement or adventure breaking it in. I also don’t want to taste 80 year old stain. I do want a safe, tasty break-in that will keep me reaching for this pipe. But even with a more recent pipe, especially if it’s a difficult shape to come by, or anytime that a completely safe break in is desired, K&P’s precarb is fabulous.

A NOS Mark Twain with the DIY K&P pre-carb coating

Someone at K&P told me they use Smart Solutions activated charcoal powder. I pass this along to you because the powder I was using in the blog post from April isn’t quite the same thing and doesn’t perform quite as well, for whatever reasons. I can’t imagine the brand of food-grade gum arabic powder matters, as bakers the world over use this stuff.


Mix the two powders at a 1:1 ratio. 1 tsp of each will make plenty of precarb for 2-3 bowls.

Add water using an eye dropper, just a few drops at a time. The consistency of the slurry should be thick, but neither runny nor like paste.

I use a square-end stiff bristle No. 8 paint brush to apply the mixture.

Begin at the bottom of the bowl and work up the sides. Use enough light to make sure you don’t miss any areas. Also make sure you don’t close over the air hole. I push a bristle pipe cleaner just to the opening, then after painting the chamber, push and pull the bristle tip just enough to make sure the draft hole is open.

Let dry for 48-72 hours.

Note that the first smokes, just as on a new K&P pipe, will produce a bit of charcoal up the airway. There is no taste and you might get whiter teeth, who knows? The precarb will melt and flake just like K&P’s. Sometimes a bit of tobacco will become fused with the forming cake. No worries. You can either smoke the bowl down 4-6 times or just smoke the bottom half of the bowl, whichever you prefer. By the sixth smokes, you will have an amazing carbon cake.



to my friend and pipe sensei,
Prof. John Schantz, C.P.G.


A 1309 Made in England with
NOS bare chamber (left) and DIY K&P Precarb (right)



Parting Shot

Giacomo Penzo, Peterson’s Pipe Specialist,
sent me this photo of his POY 2021 production prototype,
which Adam O’Neill photographed for the book,
available exclusively at Smokingpipes.com


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