Oil Curing

[marks]

I am curious about oil curing briar. I have never tried it, nor do I know where to start. I would assume that you would not use any type of oil that you could not use in food preparation, but I know some of these can turn rancid over time.

I am aware that pipemakers spend a lot of time experimenting and perfecting their methods, and are rightfully reluctant to disclose them. I would be curious on where to start my own experiments if anyone could point me in the right direction. Thanks!!

[Tyler]

Marks,

A very good question. Thanks for your post. I personally have not done any experimenting with oil curing, so I cannot comment with any expertise. This question is quite a test for this forum, because if there are any secrets in the pipe making community, briar curing and sources are them. Because of distinct tastes imparted by some curing methods, makers like to kjeep that originality to themselves. If I teach you how to make a pipe, the pipe will still be made by you and therefore look like your work. The curing processes being more scientific in nature tend to produce similar results. For this reason, I speculate, makers talk less frequently about topics such as curing.

Again, good question. I hope someone has some insight and will offer their thoughts.

Tyler

[marks]

Yes, I would be surprised if anyone that is doing oil curing discloses their methods or points me in the direction of their methods. But, I just had to ask the question. Thanks for the reply.

[KurtHuhn]

On the back cover of the current issue of Pipes and Tobaccos, there's an ad from RD Field for Radice Pipes. In one corner they show a bunch of stummels sitting in what appears to be a plastic tub of oil. The funny thing is, they look like finished stummels, maybe only needing buffed. I always figured that the stummels would be rough shaped at best.

So, now you know that at least Radice finishes the stummel before oil curing them. The mystery, though, is how they're cured.

I've heard reports that oil curing drives out left-over moisture fromt eh briar and makes it incredibly light. However, if a stummel were simply submerged in room-temperatur oil, it seems that it would absorbe the oil instead of releasing moisture and resins. So it might be safe to assume that the oil is heated, to force the moisture to boil out. But how hot, and for how long?

Now there's the question of how the briar keep its shape during the heating process? Seems to to me that the briar would end up with a raised grain due to having moisture driven out. However, it might replace that lost moisture with oil, and the grain is stabilized.

Of course, here I'm foolishly assuming that the oil curing only takes place at one point in the construction of a pipe. The thing is, it could be all throughout the process.
- The brair arrives from the supplier and is boiled in oil
- the briar rests in that oil as it's brought down in temp slowly
- the stummel is rough shaped and, it goes back into the oil
- the rough stummel is again heated in oil, but at a slightly lower temp
- the rough stummels rest in the oil as the temp is brought down
- the stummel is finished, and goes back into the oil
- the oil is brought slowly up to a certain, secret temp
- the finished stummels rest in the oil for some secret amount of time
- the stummel are brought out, wiped dry, stems are made to match they're buffed, and viola - pipes!

Of course this is all conjecture, based on nothing more than a decent background in physics....

[Tyler]

Hey Kurt!

Welcome to the Group!

Thanks for your thoughts on oil curing. As I said already in the thread, I don't know much about this process at all, but I do believe that most folks only cure at one point in the pocess. I have understood this to be after initial shaping of the stummel. I don't know how much the stummel changes shape after the process, but it sure makes sense that it would changes some. I would guess that after the process one would need tweak the shape back to the desired proportions, as well as making the stem/shank transition smooth and flush again. I wonder if this process changes the fit of the tenon and mortise? It certainly would expect that it does.

Interesting stuff...

Tyler

[KurtHuhn]

Hi Tyler! Great website you've got here. I recently redid my website as well, and considered adding a forum like this - but I think it might be redundant at this point.

I'm very curious about oil curing, and looking for more info. Unfortunately, it's one of those things that are a closely guarded secret among those that do it. I've done some thinking on the subject, and it makes sense that the curing would occur after the stummel is shaped, but before final sanding and buffiing. This makes the most sense, I think.

If it's cured after shaping, but before final sanding, that allows the maker to sand down any raised grain that might have occured during curing. If you wait until the after the curing process to make a stem, you also don't need to worry about changes in dimensions of the mortis. *However*, that would make it very difficult to properly mate a stem to a stummel since sanding them as one piece is the easiest way to make sure they're flush - at least in my experience. I suppose, if the stems and stummels are machine made, or at least machine assisted, the process would be easier, since there will be more homogeny between stems and stummels.

I don't know. I guess it depends on the process. There's so many questions, and the questions beget more questions. Like, what kind of oil? Canola, corn, peanut, olive?

Now this discussion has be very interested. Maybe I should make a couple stummels specifically for oil curing, and see what I can come up with.

[whitebar]

Kurt,

Please keep us updated on your progress. I have really been curious about this as well.

Stephen

[ArtGuy]

I have a good friend who does a lot of cooking. He told me once that when frying chicken, as long as the oil is kept at 400 degrees ( I think that was the temp. he suggested) the chicken will not absorb any oil.

I imagine the same would hold true to keep briar from absorbing any oil. Though I imagine not all pipes would survive this process.

Now that I think about it, my Ser Jacopo Jucunda is oil cured and almost looks as though it has been sandblasted and then deep fried.

[TreverT]

Here's some general info-

It's important to preheat both the oil and the stummel, and I've had best results with a very long preheat of the stummel, the idea being to dry the normal humidity in the wood to near 0% to maximize oil absorption. The type of oil is crucial, and vegetable oils have never given me anything but rancid results though there may always be one that I haven't tried.

After the stummels have soaked in the hot oil (I typically leave them overnight, to first absorb oil into the dry wood and then cool together), you have to drive the oil back OUT of the wood as thoroughly and effectively as possible. Here is where I have never gotten satisfactory results. I have worked with both copper heated pegs (stummels mounted on them for extended periods - weeks) and forced hot air (adapted heat guns). Heat the interior of the wood enough and the oil will boil back out of the wood's exterior, which is fun to watch happening. The problems here are twofold - getting the oil hot enough to boil out nearly always leaves me with a blackened bowl interior, and I'm not sure how the factories do this without burning their stummels. Secondarily, if the oil is overheated it will burn rather than expel, and the wood will taste nasty forever... a stummel sodden with burned oil is a hideous experience.

The final stumbling block is getting ALL of the oil out. Even the best results I've had, with tolerably low chamber blackening and no oil sizzle, have left trace oil in the wood which appears on the exterior as tiny moisture droplets during the first several smokes. I haven't yet been able to find a way to reliably get all the oil fully expelled. Having a two year gap in my experimenting didn't help either! But, now I have 20,000 pre-shaped stummels to play with, so there's plenty of cannon fodder for future ideas.

FWIW, in most of my experiments, the stummels would lose between 15% and 23% of their original weight, and regain only around 7% or so after re-equalizing with the local humidity.

If any of this sounds vague, it's because there are plenty of details to this that I'm not posting in a public forum

[marks]

Thanks Trever!! It sounds like one heck of a process.

[Nick]

Too cool Trever.

Thanks

[Leus]

Heh, maybe it's necessary to centrifugate and heat the stummels at the same time

[BLC]

I may have something to add...is there still any interest in this topic?

[Sasquatch]

Always! Whatcha got?

FWIW my own experiences were similar to TT's. Patchy results and lots of headaches.

[pipeguy]

It's time for the new years oil curing post Speaking for myself, I oil cure all my pipes.I believe the extra
time required is well worth the result..What makes me laugh is all the mystery that surrounds this process.I know what gives me great results ,I can't comment on other pipemakers process who do this frankly because I don't know.There are no "secrets"to this process , Just years of reading,study,and trial and error.That's why those who oil cure don't want to talk about how to do it.We put the work in and if I can do this so can you.IMHO

[BobR]

I wonder if vacuum bagging the stummels while heating would pull the oil out? That's how they cure composites.

[BLC]

wow...ok...didn't mean to wake a sleeping bear.

[W.Pastuch]

It's time for the new years oil curing post Speaking for myself, I oil cure all my pipes.

Well if you have so much experience and you've perfected this process (yet somehow I've never heard about your pipes outside of this forum...) go ahead, please tell us about your research! I'm sure there's some info you can share without revealing your final formulations.

[Tyler]

In other news, this is a rather historic post: it appears to be Kurt's first on the forum. So that's cool.

More on topic, I'm of the opinion oil curing is a waste of time. We get well cured briar these days straight from the mills. It smokes great.

If you want to mess around and play with oils, rock on. It's not critical for a great smoke though.