The Science of The Open Draw

cigrmaster · Oct 1, 2013

When I think of a pipe that has an open draw, I am talking about a shank that is drilled to around 4mm or greater. In my experience pipes that have an open draw smoke drier and cooler than ones that are not. I can put a pipe down for a couple of minutes, come back to it and it will still be smoking. Sipping a pipe with an open draw is a pleasure and flavor wise I feel I get more with this type of pipe. Now some people feel that a smaller opening will concentrate the flavors more, but in my experience I have not found this to be true. I pack my pipes fairly tight which allows for the concentration of flavors to come out very nicely.
Castello is a company famous for their open draws and the one I have is probably around 4.3-4.5 mm. I do have to pack it tighter than my 4mm pipes, but the flavors are great, it never gurgles and it smokes cool and dry.
So the big question is do any of you consciously buy pipes that have open draws and insist on it before you choose a pipe? Do some people like a tighter draw and if so what is it that you enjoy? Have people noticed that pipes you own with smaller openings gurgle a lot and have you had them opened up to stop it?

peckinpahhombre · Oct 1, 2013

I have always found this interesting. I have heard that JT Cooke uses a 3.6mm draw, but he designs his pipes so there is the same volumetric airflow from the bowl all the way to the button. So where his button comes together, the internal passage way is fanned out toward the button.
Having a large draft hole if the air passage is constricted in the stem arguably defeats the purpose.

brdavidson · Oct 1, 2013

I have actually found that my Trypis pipes have a more restricted draw and when breaking them in they were prone to gurgle. My Savinelli is used without the adaptor and has a wide open draw which I find easier to keep lit and concentrates the flavours more.

mrenglish · Oct 1, 2013

I agree an open draw is much better and it is one of the main things I consider when purchasing a new pipe.

tarak · Oct 1, 2013

I'm not sure I have the experience to say either way. Although, my current rotation consists 4 Savinellis, 1 Brigham, and 1 Mastro de Paja- so I don't even know if there's differences between those.

cigrmaster · Oct 1, 2013

peck, yes if a stem is restricted it will negate an open draw. Most pipe makers understand this and make their stems accordingly.
Tarak, I have no experience with the Brigham, but your Sav's and Mastro generally have open draws as do most Italian pipes. It is the reason why Italian pipes are considered some of the best smokers out there.

peckinpahhombre · Oct 1, 2013

Harris, I'm not sure how many are scientific about it - understanding the issue and doing something about it are different things.

phred · Oct 1, 2013

Interesting - given the number of cob pipe smokers who discard the filter (thus opening up the draw), I wonder if this is part of the reason behind the forgiving nature of a cob pipe for us n00bs. Kinda like training wheels, as it were.

drwatson · Oct 1, 2013

I have also found that I like my pipe to be more open! They do smoke better.I think that's why Savinelli's are some of my favorites, because I can open up the hole to 5/32 on every one without having to send them out because of the balsa system.

erichbaumer · Oct 1, 2013

Makes sense, my best smokers are "system pipes, which despite any supposed disadvantages have a wide-open chamber in the shank and an open ended military mount stem, and a Stanwell with a filter chamber and, of course, no filter. Come to think of it, my Vauen Dr. Perl smokes very well and stays consistently lit, and it also has an empty filter chamber. Works for me!

batdemon · Oct 1, 2013

I prefer an open draw also. While I do look for that in a new pipe, if I find a pipe I really like and the only issue is the draw, I have no qualms about opening it up myself.

latbomber · Oct 2, 2013

I 100% agree cigrmaster. I like open draws and will seek out pipes that arernt chambered for a filter and with a wider bowl and shank.

fitzy · Oct 2, 2013

I don't think I've ever noticed much of a difference.
When I get home I'll have to take a look at my pipes and see which one's have a more open draw. All of my pipes seem to smoke well. Although I think that Caminetto smokes the best Harris. I'm curious now to see if it has more of an open draw than my other pipes.

Perique · Oct 2, 2013

I think BB has forgotten more about pipes than I'll ever know....
That said, I also find myself gravitating towards my filter pipes with the filter removed. And Phred you may be onto something there about cobs.

pipestud · Oct 2, 2013

This is really a complicated subject. Some tobacco blends smoke better in a pipe with a tighter draw (usually fine ribbon, crimp or shag), while thicker cut tobaccos smoke better in pipes with a more open draw. It has been my experience that tobacco loses its flavor presentation if the draw is too wide open.
Generally speaking, I am more comfortable smoking a pipe that is opened to about 5/32 or 4 mm mainly because I regularly smoke ribbon and shag cut tobacco. And no matter what I smoke in a pipe that has a cavernous draw, the flavor mutes to the point where the experience is not enjoyable.
Pipestud

numbersix · Oct 2, 2013

Generally speaking, I too prefer an open draw. FWIW I will say that of my pipes that have a more restricted draw, I still don't experience any gurgling problems. I've always attributed that to where the draft hole sits in the bowl (though I am willing to believe it's more complicated than that).

This is really a complicated subject. Some tobacco blends smoke better in a pipe with a tighter draw (usually fine ribbon, crimp or shag), while thicker cut tobaccos smoke better in pipes with a more open draw. It has been my experience that tobacco loses its flavor presentation if the draw is too wide open.

This makes sense.

salewis · Oct 2, 2013

Rick Newcome, in his first book 'In Search of Pipe Dreams' actually devotes an entire chapter to open draw. He offers a drawing and measurements for all the pipes he buys to open up the draw. Personally, I have only one pipe of my over 40 pipes that has a tight draw. This one pipe, interestingly, is an S. Bang that was made by either Olf or Per in 1984 which was the first year they took the company over from the originally owner Sven Bang.

cigrmaster · Oct 2, 2013

peck, I think the better artisans are spending quite a bit of time on stem construction which is the reason their pipes smoke so well. Rad has told me that he makes sure the insides of his stems are completely smooth so there can be no turbulence.
roth, not over thinking, just trying to come up with a different topic for discussion is all. Let's face it, another favorite pipe thread does get a tad boring. Besides, we do love to pontificate on the minutia of pipe smoking don't we? lol
Mike makes a very good point about any type of turbulence in the stem, that can cause all kinds of issues no matter how open the draw is.
Fitzy, if memory serves, I could double two pipe cleaners and jam it through the shank into the bowl when I cleaned that Caminetto, which in my mind makes it at least 4mm probably 4.3. The stem opening was a tad small, but it did smoke fantastic, if it were vulcanite you would have never got your hands on it. I am very glad to hear you are enjoying it.
Pipestud makes a good point about the type of tobacco being smoked, I smoke only flakes and find the larger shank dimensions smoke them cooler and drier and have better flavors than a tighter pipe.

wcannoy · Oct 2, 2013

Now as far as open air passages. Personally I like an easy open draw. A draw that allows an easy pass for a pipe cleaner. That can be anywhere from 3.5mm to 4.5mm in the shank and from 2.5mm to 4mm in the stem. The more pipes I go through the more I am not so sure it is the evenness of size of air passage that makes the difference, but the smoothness of transition.

Agreed, and good to see you Mike!
I drill shanks out at 4mm, and stems out at 3.1mm, always taking great care to make smooth transitions with no hangups. The customer feedback regarding the smoking qualities of my pipes is always positive.
P.S. - The "volumetric flare" of the airway at the button has become standard practice for artisan pipemakers...

taerin · Oct 2, 2013

Having an open draw is very important to me, it allows me to puff slower and keep the pipe lit as Harris has stated before. I won't smoke a pipe that isn't open, however I don't require it to pass a pipe cleaner as I prefer fully bent pipes and it's a real bitch to find ones that easily pass a pipe cleaner, especially if you have a system pipe(better chance of getting struck by lightning). I will run a pipe cleaner through any pipe multiple times a smoke to keep the smoke as dry as possible and to preserve the flavors. Some vintage pipes have really super restrictive draws on them, I had to sell a couple like that myself, it's really sad getting these relics from the past only to discover that they are not smokable...
I would like to add, the flange on the end of the fishtail that redirects the smoke to a wider angle is critical for dispersing the smoke through more area in the mouth. A stem with just a hole in it won't do nearly as good of a job, had a pipe once that was fishtail with only the hole in the end, just hated it for that reason.

The Science of The Open Draw

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