For a basic outline of the vulcanization of natural rubber to create "ebonite" or hard rubber, check out this video with a saxophone backing track and a voice-over by a woman who really, really likes vulcanization. The flexibility or hardness of the rubber is basically in direct relationship to the amount of sulfur in the recipe, although other additives were later used to produce different properties. Ebonite was first used because of its resemblance to the ebony wood originally used for woodwind mouthpieces.
That's the benefit of hard rubber; it machines more reliably than ebony, it is more stable, and it is less expensive. As an added benefit, with an investment in the proper equipment, it can be molded into a blank that eliminates much of the preliminary machining, including difficult chamber work. It's final advantage to some is that it feels like wood in the mouth. Many people prefer it to the feel of metal or plastic.
Originally, ebonite was processed in the same manner as ebony for making mouthpieces. A hard rubber manufacturer produced ebonite in a dowel shape, called bar or rod rubber, and the rod was cut into sections and machined by the mouthpiece maker just like making a mouthpiece from a piece of ebony wood dowel. Mouthpiece makers in the early 1900s were already set up to machine ebony wood, and by purchasing rod rubber, the same milling process could be used. Milling is still done today, although you would pay for the rod rubber and then mill away 80%, meaning that there are higher material costs for milling rod rubber. On the other hand, milling rod rubber means that the maker doesn't have to make molds, mix raw ingredients, cook the rubber (in an expensive autoclave for many hours), etc., although the modern milling process for rod rubber can also require very expensive machinery.
If you had expensive and complex milling machinery, and were adept at milling, you would claim that rod rubber made superior mouthpieces. If you had expensive and complex equipment for molding, and were adept at molding, then you would claim that molded hard rubber mouthpieces were superior. That's the difference in the two processes. Or at least, that's all we have evidence to support. We know that there is no discernible difference because several of the most respected vintage mouthpiece makers went back and forth between molded and rod rubber pieces, as shown in this blog.
Notice that I did not make any acoustical claims for hard rubber, whether molded or rod rubber. For that, we would need extraordinary evidence, of which there is none. There is some anecdotal evidence where some people claim that they clearly hear the difference. But we are back to the Princess and the mouthpiece type of story discussed in an earlier blog. Since the claim is not really evidence, it is hard to rebut. It is similar to this type of revealed knowledge: "What's that you say, Lord? You say that hard rod rubber is acoustically superior? Then that shall be my proof!" Okay, they are welcome to their beliefs, but don't try to convince others by claiming that there is evidence.
Support for the claim that "good" vulcanized rubber for making mouthpieces is no longer available is sometimes tied to the Environmental Protection Agency. The assertion is that good hard rubber mouthpieces disappeared when the EPA promulgated rules in the 1970's related to hard rubber manufacturing. So that's what happened! Wait a minute. This is two claims. The first is that good hard rubber can no longer be produced. The second claim is based on the inception of the EPA in December of 1970 coinciding with the alleged disappearance of good hard rubber. The second claim sure sounds like it could be the infamous post hoc fallacy. Mr. Sagan is going to require that we produce some extraordinary evidence for these claims.
Well, for our primary evidence, how about the disappearance of the U.S. tire industry at exactly the same time? Oh yeah, that never happened. According to the Rubber Manufacturer's Association (RMA), U.S. tire manufacturer's produced 307.9 million automobile tires at 55 production facilities in the United States in 2013 (a .5% increase over the prior year). So the production of vulcanized rubber products in the U.S. is alive and well despite the EPA.
Yeah, but how about the burdensome aspect of EPA rules driving mouthpiece manufacturers out of business? Turns out that the EPA rules allow members of the RMA to "self report," meaning that the manufacturers tell the EPA what materials they are using and what waste products are produced. It's not like the EPA is peering in their windows at night. The publication also lists the hundreds of hard rubber manufacturers still producing products in every state in the U.S. So much for the EPA rules having eliminated hard rubber production.
Not too surprising, it is the "waste" that is the biggest environmental concern. Think of the tire industry again. Everybody has heard of the nightmare caused by stockpiles of worn-out tires. Add to that the number of "blems" or tires that don't meet production standards right at the factory. The automobile tire waste stream is thousands of tons of vulcanized rubber per year. The EPA is still searching for a solution, but the problem clearly hasn't ended the production of hard rubber products.
It's silly to allege that the EPA was so concerned with the waste stream of hard rubber mouthpiece manufacturing that it regulated the industry out of business. One thousand defective mouthpieces a year equals one truck tire. Would the EPA even require that a producer self report a defective mouthpiece? I don't know, but the idea that hard rubber mouthpieces disappeared because of the EPA doesn't fly.
The claim that vintage hard rubber contains some recipe or materials that are no longer available is harder to examine, but ultimately just as silly. Latex rubber is still available. Sulfur is still available. Lamp black is still available (as a colorant). Talcum powder is still available (as a mold release). There are a host of other ingredients that have been used over the years, as listed in the EPA publication above, but the materials are hardly a secret and none became suddenly unavailable. The same is true with the ratios and recipes. As can be seen in the EPA publication, hundreds of manufacturers in the U.S. still avail themselves of materials and recipes. And if you don't know the ratios and formulas, there's always the RMA to help you develop them.
The secret "formulas and recipes" claim is sometimes used in supporting the superiority of one vintage mouthpiece over another. I also find this claim entertaining to examine. I don't know how many times I read a claim like "these old Penzel-Mueller hard rubber mouthpieces used the best vintage hard rubber." Those old Penzel-Mueller pieces were made by American Hard Rubber (and later Riffault), as were pieces for WoodWind Co. N.Y., as were some Links, some Dukoff, some Vito, some no-name, etc., etc. So you can substitute just about any vintage name into the "best vintage hard rubber" claim. Sort of weakens the claim from the get go.
But we need some extraordinary evidence to support the extraordinary claim of extraordinarily rare and superior vintage hard rubber. The French company Riffault made blank mouthpieces for the above names and many others (Riffault also made most of the blanks for Lelandais and Chedeville, both of which are claimed to have still used rod rubber decades after they began using commercially available blanks. More on the silly "rod rubber" fetish here).
If true, the "best vintage hard rubber" claim would require daily conversations at Riffault's manufacturing facility in Mehun sur Yevre, France* to go something like this (spoken with a French accent, but of course),
I don't believe that woodwind mouthpieces ever drove the production of the type of rod rubber that was being produced. Woodwind mouthpieces comprised a tiny fraction of the mouthpieces made of hard rubber. Smoking pipe mouthpieces (i.e., pipe stems), which were made by the hundreds of thousands, were also made of ebonite. And a new-fangled device called a telephone required the production of a thousand times more hard rubber mouthpieces (and ear pieces) than did the saxophone industry. ("Boy, those old hard rubber telephone mouthpieces sure sounded better than any of the newer telephones. The best being those that were milled from hard rubber rods, but of course.")
Different hardnesses of rod rubber were available from a manufacturer, and still are available (as seen here, measured by a durometer in units of hardness called duros), but the generic term "ebonite" for a type of hard rubber is a durometer measure for a certain hardness of vulcanized rubber, i.e., a hardness that mimics ebony (a reading of 100 on an ASTM D2240 type A durometer).
Molded ebonite mouthpieces, especially the improved production techniques of Maurice Riffault in 1928, with further improvement in the 1950's when his daughter, son, and son-in-law joined the business, must have been tough competition for rod rubber mouthpiece makers, as is evidenced by the vast majority of makers and saxophone companies turning to molded pieces. As early as the 1920's, 90% of mouthpieces were made from molded blanks.** Read that last statement again. By the 1930's and 40's, rod rubber mouthpieces were as rare as hen's teeth. That's because makers had learned that there was no advantage to milling from rod rubber (although some would still claim that they were using some secret process like "eburnated bar rubber" without admitting that it was a molded blank).
Because of some early hype about the superiority of mouthpieces milled from rod rubber, many vintage mouthpieces sold today are claimed to be made from "superior" rod rubber. That's false on two accounts. First, there's no evidence that rod rubber produces a better mouthpiece. In fact, most claims about how mouthpiece matters are demonstrably false.
Second, there are very, very few vintage pieces made from rod rubber. In the U.S., it is reported that the American Hard Rubber Company (AHR) produced the rubber rod used by some early American mouthpiece makers. But huge advances were quickly made in the molding of hard rubber. Automobile tires were one use. AHR had its big success not with tires, but with a molded American icon, the ACE comb.
There is evidence that AHR produced some of the rod rubber used for saxophone mouthpiece production, but by the 1930's, even AHR had begun selling molded mouthpieces to refinishing businesses like Link, Penzel Mueller, and Woodwind Co. AHR is where Arnold Brilhart bought his first molded blank mouthpieces for the creation of his hard rubber line of pieces.***
For the most part, the mouthpieces that were actually made from rod rubber in the early 1900's are easily recognized because they are dark, stuffy, and unwanted. Thermoplastics in the 1940s must have been some tough competition for molded hard rubber mouthpiece makers. At some point, definitely by the 1970's, reduced costs became an even larger factor in mouthpiece marketing (as in the case of general saxophone production) and there were more "student grade" mouthpieces, just as there were more student grade instruments.
Here's a recent Ebay auction for a Riffault clarinet piece in a standard facing. Click on it to enlarge.
That's right, two bids and it's already over $800 for a clarinet mouthpiece. I buy vintage Riffault tenor saxophone mouthpieces for under $30 each. That's on the low side for vintage Riffault sax pieces, but I don't spend the extra money for those mouthpieces claimed to be made of the "special vintage hard rubber."
It could be that the secret formula hard rubber in the Riffault clarinet pieces really is 25 times better than the rubber used for Riffault saxophone pieces. That would make Riffault clarinet mouthpices like the super-duper rubber recipe used in the vintage Otto Link Tone Edge, which routinely sells for over $1,000. Or, it could all be hype. We would need extraordinary evidence proving the difference. And unfortunately, the evidence that I have concerning super-duper rubber recipes is from asking Jacques Mimault, the last CEO of Riffault et Fils about Steelite Ebonite. His comment is in this blog.
Keep in mind that those who agree with the extraordinary claims regarding the hard rubber used in vintage mouthpieces tend to be the owners or sellers of those pieces. Take a claim like "This Otto Link Tone Edge 'Slant Signature' plays great because it is made from superior vintage eburnated bar rubber that you just can't get anymore." Full disclosure, I have one. Fuller disclosure, I really, really understand the desire to say that. Fullest disclosure, it just ain't so.
This last claim brings up some more saxophone lore, that of "early Babbitt" mouthpieces. The evidence we have is that Babbitt molded blanks for Otto Link from the early 1940's, when Link had clearly stopped producing from rod rubber. Yet "early Babbitt" is a term used based on the address on the box that came with the mouthpiece and is generally claimed to be sometime in the 1970's. With absolutely no evidence, it is claimed that the hard rubber used by Babbitt for making Link mouthpieces is superior to what Babbitt used when producing dozens of other name brand mouthpiece. Again, with zero evidence and no logical explanation to support the claim. It's kind of funny, unless you paid an extra $500 because of the "early Babbitt" hoax.
The era of the production of the mouthpiece is a better indication of the form of hard rubber used than is the trade name stamped on that particular piece. As noted above, by the 1920's, the vast majority of mouthpieces were molded. Sellers often represent that certain names (Lelandais and Chedeville come to mind) had their "golden age in the 1930's and 40's making "rod rubber" mouthpieces. But there is no evidence that Lelandais or Chedeville still used rod rubber in the 30's and 40's and some evidence that they had also switched over to using molded blanks manufactured by third parties (as had Otto Link). So much for the "golden age" of rod rubber. The claim is further complicated by the obvious use of Riffault et Fils molded blanks by both Lelandais and Chedeville.
Finally, common-as-dirt vintage hard rubber pieces are much more uniform in material than the multitude of trade names stamped on them would imply. There is no evidence that the large mouthpiece producers cut corners by routinely changing the formulas from one production run to the next (nor is there any evidence that a "good" hard rubber formula was any more expensive or complex to produce). There isn't even any evidence that hard rubber manufacturers ever produced ebonite specifically for a saxophone mouthpiece that differed from that of a vintage pipe mouthpiece or vintage telephone mouthpiece.
So why did some vintage brand names become popular while some faded away? This is curious because some of popular vintage brands used the exact same blank as the less familiar brands (and even no-name pieces). My belief is that it is in the quality of the finish work. That shouldn't be too surprising. When the table, the lay, and the chamber have a quality finish that is superior to a piece made from an identical blank, it shows when played. But the intricacies of table, the lay, and the chamber modifications are largely invisible to most players, so the sound produced is erroneously thought to be related to the mouthpiece material, which is erroneously thought to relate to the trade name stamped on the piece. Mouthpiece makers were only too happy to further this misunderstanding.
My experience is that, despite claims of super-duper hard rubber, the quality of vintage mouthpiece materials is generally the same from piece to piece, as shown by various trade names having been used on identical blanks from the same producer.**** The uniformity of the ebonite material used in vintage pieces and the ready availability of vintage no-name pieces leads me to discount the claim of "superior and wonderful" hard rubber in any particular piece. That claim only makes me wonder what other unsubstantiated puffery is being used by the seller in describing how the vintage mouthpiece actually plays.
*The fact that Riffault et Fils was located in France, had a huge segment of the American mouthpiece market, and also appeared to have ended production of hard rubber mouthpieces in the 1980s is either evidence of the secret international power of the EPA or another coincidence unrelated to the EPA. What happened to Riffault is a story for another blog that is not yet finished (unless this text is a link).
**The Music Trades, Oct. 7, 1922 (interview with G. Langenus stating that as early as 1922 "90% of saxophone mouthpieces sold are cast").
*** Saxophone Journal, March/April, 1989 (interview with Arnold Brilhart).
****The only really inferior hard rubber that I have come across was a Penzel-Mueller mouthpiece that was made from a blank probably produced by American Hard Rubber in the 1940's. The rubber had a little bit of a grainy look to it, like there were specks of something that had not completely mixed prior to molding. Deep inside the chamber, at the point of the thickest material, there was a blister. When I picked at it, the surface broke away and there was a void. So it is certainly possible to produce defective molded hard rubber. Had this piece been milled from defective rod rubber, the defect might have been more apparent. Or not.