Oil Curing
Oil Curing
Does anyone know of or have any information on the Oil Curing of Pipes? (like Dunhill used to do and Ashton does) I have managed to piece together some information on it but not the full story. I know the process uses 3 oils but I only know of two, linseed and rape (canoil). I have read that you heat the blocks for 8 hours ( what temperature ??) then soak them in the oil mixture (again what temp ??) then heat them for two weeks to push out the oil and impurities (how that is one I don't know). Anyone know more than this????
Dunhill Patent Oil Curing
I read in the latest Pipes and Tobaccos magazine that Michael Butera found the original Dunhill Patent for oil curing. So I went searching. You might find this interesting.
http://www.folloder.com/pdf/1341418.pdf
I think I also remember seeing in another Pipes and Tobaccos magazine on curing that Dunhill only used one oil, but carvers who left Dunhill later worked at improving the process and went to three oils.
http://www.folloder.com/pdf/1341418.pdf
I think I also remember seeing in another Pipes and Tobaccos magazine on curing that Dunhill only used one oil, but carvers who left Dunhill later worked at improving the process and went to three oils.
Nice! Trees. I had also read that but I failed to search out the patent! I am glad that you aren't as lazy I was!
In the US patent application, he mentioned the UK patent GB191302917. I went and looked at that (sorry couldn't figure out how to make a link to it). Only half of it is there but he does go into a bit more of the history of it. He mentions in the patent that oil curing was normal for high quality pipes at that time but that after the soaking the stummels were "frequently stored for a considerable period of time, such as twelve months or longer, to ensure the perfect incorporation of the oil with the fibers....and thouroughly season the pipe." He goes on to write that this is done so as to prevent the problem of oil seeping out of the pipe when it is first smoked.
He doesn't mention much about the soaking in oils process (though in the US patent he mentions soaking Algerian briar in olive oil!!!!) but goes to great length describing practicle elements of how to operate the heating pan to expell the oil from the stummel.
I think that I read that Butera and, also, Roush (learned from Butera) oil cure their pipes. Anybody else heard that and maybe a bit of what they do??
In the US patent application, he mentioned the UK patent GB191302917. I went and looked at that (sorry couldn't figure out how to make a link to it). Only half of it is there but he does go into a bit more of the history of it. He mentions in the patent that oil curing was normal for high quality pipes at that time but that after the soaking the stummels were "frequently stored for a considerable period of time, such as twelve months or longer, to ensure the perfect incorporation of the oil with the fibers....and thouroughly season the pipe." He goes on to write that this is done so as to prevent the problem of oil seeping out of the pipe when it is first smoked.
He doesn't mention much about the soaking in oils process (though in the US patent he mentions soaking Algerian briar in olive oil!!!!) but goes to great length describing practicle elements of how to operate the heating pan to expell the oil from the stummel.
I think that I read that Butera and, also, Roush (learned from Butera) oil cure their pipes. Anybody else heard that and maybe a bit of what they do??
In one of the early issues, I believe, P&T had an article on Ashton or some other Dunhill-ish brand that discussed oil-curing, and showed a rack of stummels drying on heated pegs after soaking in oil. Seems like drying took a long time (fairly big number of weeks or small number of months, can't remember which), and that the oil mentioned was a blend of nut oils -- walnut, for instance. I haven't developed a curiosity about it, yet, but I'd probably start by finding walnut, almond, peanut, whatever oils I could, and tasting them. Then burning them with a wick, then dunking a few stummels. I seem to recall from the article that the stummels being dunked looked fairly close to the final shape, but I don't know if the oil curing process changes dimensions to the point that you can't, say, drill a mortise beforehand.
Interesting with the nut oils. Peanut oil would be the most likely choice, at least from my experience cooking. It has a very high burning temp (meaning that it can get very hot before it starts to smoke) and it is known for not imparting flavor to the food.
I went to pt-magazines index and the only article on Dunhill was in the first issue (Vol 1 No. 1) on page 38. Anybody have that issue or know where to get a copy?
I went to pt-magazines index and the only article on Dunhill was in the first issue (Vol 1 No. 1) on page 38. Anybody have that issue or know where to get a copy?
I just found this German site that had Dunhill's full, UK patent application from 1913. It has diagrams of the oil expulsion device they used.
http://www.pipewolf.com/pipe%20infos/oil%20curing.htm
http://www.pipewolf.com/pipe%20infos/oil%20curing.htm
I found a little bit more information about the process from the sandblast patent application of John William Taylor, from Ashton.
After describing how to perform the sandblast finish of his, he mentions that the pipe bowl "may then be seasoned by soaking in vegetable oil and subsdquently heated, preferably on a coppyer heat plug at about 140 degrees C. Dried oil and and more soft-grain wood may be removed by said sand blasting."
So now we have a temperature for the end process, 140 degrees C (circa 285 defrees F)
There is more specific information in the application. Once I have read it then I will post a summary. Radice oil cures also and they have some pics of the process at their site. The simplicity of what they show reveils much about the process.
After describing how to perform the sandblast finish of his, he mentions that the pipe bowl "may then be seasoned by soaking in vegetable oil and subsdquently heated, preferably on a coppyer heat plug at about 140 degrees C. Dried oil and and more soft-grain wood may be removed by said sand blasting."
So now we have a temperature for the end process, 140 degrees C (circa 285 defrees F)
There is more specific information in the application. Once I have read it then I will post a summary. Radice oil cures also and they have some pics of the process at their site. The simplicity of what they show reveils much about the process.
Where did you get the information that the JH blocks are oil cured? I believe that you are mistaken with this information. The only "curing" that suppliers refer to is the simple process of time alwaying the blocks to dehydrate for a few more years.
Briar producers boil the blocks for 12 - 24 hrs in water shortly after the blocks are cut from the burl. They are than slowly dried out, in a controlled environment. To the best of my knowledge no briar producers oil cure the blocks. The oil would have a hard time penatrating that deep into the block.
Oil curing is used to expel the last bit of sap and resins that are left in the wood that the before mentioned boiling process didn't remove. Typically, this process is performed after the majority of the excess wood has been removed and the rudimentary summal shape has been formed. Many pipe makers, the Danes as a general rule, rough form the stummal then let it "cure" (meaning dry out more) for a year or more. After this period they finish the pipe.
Butera and Roush perform an additional curing process, I believe that this is in a water solution. What else is in the solution, aside from water, I am not sure. Then, they dry the stummal out and finish the pipe. Again, this is done to remove any resin and sap that may still be in the wood.
Radice, Ashton and Charatan (and 100 years ago all "good" pipemakers did it) oil cure. The process cleans out the pours in the wood (helping to cool and dry the smoke better). It also makes the pipe lighter (go figure...adding oil makes for a lighter pipe I guess Atkins was right!! 8O ). Historically, Dunhill oil cured but are said to have stopped in the early 1960's. I don't have hard facts on that they stopped but Taylor, of Ashton pipes, left Dunhill after decades of working there to start up his own shop. Whereupon, he oil cures his stummals.
The benefits are also a much better "break in" period for the pipe. It adds a light, nutty flavor to the smoke during the first 20 - 30 pipe fulls.
It is an expensive process, both time and effort, to oil cure. If it didn't do anything then one would think that the companies wouldn't do it.....
Briar producers boil the blocks for 12 - 24 hrs in water shortly after the blocks are cut from the burl. They are than slowly dried out, in a controlled environment. To the best of my knowledge no briar producers oil cure the blocks. The oil would have a hard time penatrating that deep into the block.
Oil curing is used to expel the last bit of sap and resins that are left in the wood that the before mentioned boiling process didn't remove. Typically, this process is performed after the majority of the excess wood has been removed and the rudimentary summal shape has been formed. Many pipe makers, the Danes as a general rule, rough form the stummal then let it "cure" (meaning dry out more) for a year or more. After this period they finish the pipe.
Butera and Roush perform an additional curing process, I believe that this is in a water solution. What else is in the solution, aside from water, I am not sure. Then, they dry the stummal out and finish the pipe. Again, this is done to remove any resin and sap that may still be in the wood.
Radice, Ashton and Charatan (and 100 years ago all "good" pipemakers did it) oil cure. The process cleans out the pours in the wood (helping to cool and dry the smoke better). It also makes the pipe lighter (go figure...adding oil makes for a lighter pipe I guess Atkins was right!! 8O ). Historically, Dunhill oil cured but are said to have stopped in the early 1960's. I don't have hard facts on that they stopped but Taylor, of Ashton pipes, left Dunhill after decades of working there to start up his own shop. Whereupon, he oil cures his stummals.
The benefits are also a much better "break in" period for the pipe. It adds a light, nutty flavor to the smoke during the first 20 - 30 pipe fulls.
It is an expensive process, both time and effort, to oil cure. If it didn't do anything then one would think that the companies wouldn't do it.....
I remember reading some where that the expelled oil needs to be wiped off every now and again. Is this correct? Somthing in my memory tells m that the oild kind of hardens on the outside of the stummel.
It seemes pretty rough to have to wipe the block every few hours, especially around 2 am. What happens if you don't wipe it? Perhaps one could rough shape it, do the oil thing, and then fine shape it?
Additionally, how long does one soak the stummel for? And then how long to heat the stummel? These seem to be the pertinant questions.
It seemes pretty rough to have to wipe the block every few hours, especially around 2 am. What happens if you don't wipe it? Perhaps one could rough shape it, do the oil thing, and then fine shape it?
Additionally, how long does one soak the stummel for? And then how long to heat the stummel? These seem to be the pertinant questions.
Hm! That was interesting. Frankly, the oil curing technique (Dunhill) makes sense. This is one of the reasons why oil-tempered steel is less brittle than water-tempered steel: the crystallization of the metal is altered by the viscosity of the oil and made smaller, where as with water the crystals are actually made sharper and turn slightly away from one another (if that makes sense).
I'd be interested in experimenting with the oil-curing technique myself!
I'd be interested in experimenting with the oil-curing technique myself!