New entry in my workbench blog

[LatakiaLover]

Putting it here because it's about stems:

http://precisionpiperepair.com/BLOG/index.php

[hazmat]

Good article, LL. And an interesting perspective. If a maker isn't yet ready to make the move to handmade but wants an extent of creative freedom, this is a good trade off. There's an interesting thread here: viewtopic.php?t=17 in which John Crosby mentions doing exactly this. When I came across it in my quest for stem skills it was a moment and I bought up a bunch of the things. If it could only become accepted amongst the masses as a "blessed and proper method" of achieving a well-crafted stem for lower cost(to both maker and buyer) that would be excellent.

[geigerpipes]

Good article LL

One difference in rodstock compared to premolds when it comes to Ebonite is that rod is much more dense(more compressed?) than premolds and therfore will not oxidise as quick... furthermore many premolds can have quite some age on their neck when you buy them as there are not many "new" premolds being made third the interior holes on premolded ebonite stems can sometimes be off center and with small defects ...

As for acrylics my knowlege there is limited and a stem made of rod might hold the same densety as a premolded one and the difference might be less

[RadDavis]

One thing to note also, is that you can't get cumberland in a molded vulcanite stem.

Acrylic stem blanks that I have seen (used by Tinsky) are not molded, but cut and drilled from rod or bar stock on a CNC machine, so they are virtually the same as acrylic rod/bar stock and can be modified internally to the maker's preferences. They also cost about 2-3 times what a molded vulcanite stem does.

And as Love notes, there is a big difference in the quality of rod vulcanite vs. molded. I've had a Peterson out fishing that had the stem turn brite green on top after a day in the sun, and I've never had a stem made from rod stock do this.

Rad

[Frank]

One difference in rodstock compared to premolds when it comes to Ebonite is that rod is much more dense(more compressed?) than premolds and therfore will not oxidise as quick...

This is correct in my opinion, but the oxidation may be more due to a higher sulphur content. I used the same technique customizing oversized premoldeds for my "Oom Pauls" and these stems will show oxidation within a few short months. There's your trade off.

[LatakiaLover]

Thanks for the feedback & info, guys.

I've heard there's a difference in raw material quality before, of course, but seen quite a mixed bag regarding it. The assumption that rod is the superior stuff chemically is widespread, but "field research" (if you want to call repair work an inadvertent form of that) doesn't actually show that to be the case. In fact, the worst/fastest oxidizing vulcanite I've ever seen is the rod stock used by Charatan. Dunhill isn't so hot, either. It also seems to vary by batch/period/year.

I'm NOT saying a difference of some sort doesn't exist---without a chemical analysis and controlled tests, such a claim would be baseless. What I am saying is that the clear-cut difference you'd expect to see if it WERE the case isn't there. The water is much murkier in reality that the models predict.

It is surprising. I certainly was after all I'd heard, but there you go.

Something that no one takes into account and could be adding to any myth-making is that cheap(er) pipes aren't treated the same as expensive ones. Meaning by their owners. From long term storage to post-smoke cleaning, the more a pipe costs, the better that care is likely to be. And with rubber, the better it's treated, the longer it stays black. No argument there.

All the above concerns vulcanite only, btw. Lucite varies in quality and "recipe" around the world (any of you run across the Russian "becomes putty when heated" version yet? ), but what goes into rods and blanks is definitely the same material when referring to the two big players.

Also Radney "Mr. Cumberland" Davis his bad self is right about that. Ya want swirly stuff, it's rod or nothing.

Thanks again for your interest, guys. The PipeWorld is filled with things like this. Lots of tradition and veneration born of custom, repetition, and (occasionally) outright ignorance. It is easy to find people with an opinion, but almost never is it one formed from firsthand experience. Take the "increased surface area results in a cooler smoke" claim that Dunhill had in its advertising for many years. It's one of those stands-to-reason things, but actual smokestream temp tests simply don't bear it out. Yet, I saw a raised voices shouting match at a show once over the issue.

I repeat: I'm NOT saying the molded vs. rod raw quality difference claimed by most doesn't actually exist---I don't know. I am saying I've not seen what one would expect if that were the case, and so am digging into it.

[geigerpipes]

In fact, the worst/fastest oxidizing vulcanite I've ever seen is the rod stock used by Charatan. Dunhill isn't so hot, either. It also seems to vary by batch/period/year.

I doubt neither charatan nor Dunhill use rodstock to make their stems to do so would simply not be economical in a "factory pipe"

when it comes to the ebonite rod vs. premold debate..ask yourself this:
if premolded stems where as good qualitywise
why do most if not all artisan pipe makers crafting ebonite stems do so using rodstock? simply to feed the myth?

The fact is once you get good at cutting stems from rod it is almost as quick as using premolds and besides its supirior quality it has other machining advantages...

[LatakiaLover]

I doubt neither charatan nor Dunhill use rodstock to make their stems to do so would simply not be economical in a "factory pipe"

Oh, they definitely do. (Either that or they're both lying about it and have a closed room where they do their real work, while the one visitors get to see is only for show... )

[KurtHuhn]

One very important thing to note is that, due to the fact it needs to squirted into a mold, molded stems are made of a softer rubber. It's pretty obvious when working with the stuff. Also, the rubber that molded stems are made from has a higher incidence of inclusions, and I ran into a bunch a couple years ago that all looked like they were filled with mica or vermiculite - some shiny thing that made the stems sparkle in the right light. Was very odd.

I've also noticed that the molded stems are *very* sensitive to heat. This is probably due the chemical makeup of the ruber, since they need to molded. They can be easy to heat and bend, but they also burn very easily - and once they burn, it's near impossible to sand out the scarring.

They have their place, I use them quite a bit. As long as you're careful while sanding and applying heat for bending, you should be okay. You also need to make the time investment for modifying the airway, bite area, and button. Once you do that, they are as comfortable and good smoking as stems from rod stock. However, it's my experience that they won't last nearly as long before oxidizing - that's why they never go on my higher grades.

[Tyler]

Something that no one takes into account and could be adding to any myth-making is that cheap(er) pipes aren't treated the same as expensive ones. Meaning by their owners. From long term storage to post-smoke cleaning, the more a pipe costs, the better that care is likely to be. And with rubber, the better it's treated, the longer it stays black. No argument there.

Not true that pipes of preformed and handcut stems are always treated differently. Being a pipe guy that mostly owns pipes of my own manufacture I have pipes of both rod and premolded stems that I treat all the same: badly. There is a WORLD of difference in the rod stock and preformed stems that I have used. I have bitten through preformed -- never rod. The oxidation rate is crazy different. My preformed oxidize very quickly, but by contrast the rod stems do not oxidize quickly at all even though I have never even polished some of the rod stock stems. They were rejects and went straight of the belt sander into my mouth. WAY more surface area to promote oxidation. I measure the oxidation rate of preformed in days or weeks, and rod in years.

That said, I am using the best rod stock from Germany. It's good stuff. The first rod I ever bought was not from the Hamburg factory and was VERY inferior to the good German stuff. It was resistant to oxidizing, but it was way too soft. It took teeth marks so easily you couldn't prevent them.

I have no idea the general quality of the preformed stems I used. No doubt there is a variety of quality there as well. Mine came from Pimo, JHLowe, and I bought out two different pipe makers of their old stuff and had LOTS of unknown stems.

Without a doubt the best German rod stock is VASTLY superior to the preformed stems that I have used.

Tyler

[LatakiaLover]

This is quickly emerging as one of those things where the details matter a lot, but people REFER to generalities.

A similar example is, "Diesel engines are short-lived and unreliable." Not a difficult opinion to have found through the 80's and well into the 90's. Never mind that the most reliable engines ever made, then as well as now---the ones found in heavy trucks, locomotives, and marine craft---are diesels.

The problem? General Motors' put high compression heads and a diesel injection system on their 350 V8 gasoline engine, and took it to market without testing in the late 70's. (Because diesels must be designed from the ground up to handle higher operating temps, such a conversion simply can't work.) They did it to try to capitalize on a fuel crunch at the time, btw.

Result? Lots of bad press about diesel engines, and it was rare to find someone who didn't know someone who'd been burned by a GM 30K-mile special. That they were "bad" was repeated endlessly, and categorically by consumers, to the point that with a few minor exceptions, there STILL aren't diesel passenger cars available in the US thirty years later.

Hearing testimonial-type evidence from carvers like Kurt and Tyler who have made a fair number of pipes makes it clear that there IS an issue with molded stem consistency. (Rod consistency, too, for that matter. Many "InstaGreen" Charatans and Dunhills have gone through my hands.)

Further research is indicated.

Something that might bring some clarity to all this in the semi-near term is there now there are only a small number of manufacturers. Getting a handle on what precisely is being referred to---a Caterpillar marine diesel, or a General Motors 1979 350 V8 conversion---will doubtless get easier.

Thanks again for all the feedback. Much appreciated!

[RadDavis]

Ok then how about this: I find the German rod stock that comes from that factory in Hamburg (there's only one that I know of) is vastly superior to the Guidici molded stems that I used to use.

Rad

[LatakiaLover]

Rad -- Bingo. THAT is the sort of information that will contribute to a clearer picture. Thanks.

[TreverT]

Some random trivia:

Molded cumberland stems were available at some time in the past. I don't know from who or when, but when we bought all our shop and stock, I inherited a small box of them - all obviously molded. They were odd, and different in color tone - a bit lighter. So at least at some point in history, someone made them.

Molded vulcanite stems vary insanely. I've got piles of them here that are French-made, and the quality is *excellent*. They've been sitting in boxes for years - hell, possibly decades - and they're still naturally shiny black. I've used these on test pipes here and they keep their shine very well indeed, easily comparable to black rod stock. I also have mixed in large batches of molded stems from other makers, (many Guidici, many more unmarked) of lesser quality. Many of these are already dark green, and I just toss them, knowing they'll be hopeless as stems.

[TreverT]

And one other thought - Yes, it's absolutely true that being hand-cut doesn't automatically make a stem superior to a molded one. I've seen numerous handcut stems that were cruder and thicker and generally all-around poorer quality than a decent molded stem. It's one question I'm sometimes asked about our Ligne Bretagne pipes - People want to know why they don't have handcut stems when they've "seen" pipes in the $150-ish range that DID have handcut stems. To this, all I can say is, "Yeah, so have I. And that's why I use good quality molded ones." Doing a good handcut stem is a long and laborious process that usually takes as much time as making all the rest of the pipe, and trying to make a handcut stem within thirty bucks of labor time is asking for painful results.

FWIW, the "pseudo handcut" stems of the blog article (ie, taking a big thick CNC-cut readymade and shaping it down to fit) is done by a lot of makers in the biz, and readily referred to as "handcut" in most cases.

[Nick]

Yea, I know of one high grade American maker who does that.