Boxcar, did you work at one of the ball plants? I’m curious how you know all this
Do you have any knowledge of the phenolic resin shrinking over time (due to inherent chemical properties, not friction wear). Do you know if the manufacturing plants tested for this?
No, I did not work at ABB Co. and of course they were the only plant in the USA that manufactured phenolic resin balls. I have had a couple of acquaintances who were fairly close to the plant and I have asked questions over the years. As boogieman said, temperature affects plastics. The good news is that it usually affects plastics of the same molecular structure about the same way. Phenolics react differently from styrenes and poly resins, etc. Boogieman would know a lot more about that than I do.
I'm real interested in the procedures and practices used at the time of the birth of phenolic resin pool balls. Raschig was around before WW II and was working with phenolic resins then but there is no direct written or collected evidence that they were building phenolic balls at that time. If anybody reading this has a documented set of pre-war Raschig phenolic resin snooker balls, please let me know. Anyhow, Brunswick first cataloged phenolic resin "Red Dot" cue balls and phenolic resin "Centennial" Carom balls in 1948, which means that they had to have been available in 1947. Those balls were exported to Brunswick and ABB Co. from Composition Billiard Ball Co. in London England. CBB Co. and ABB Co. were both owned by the same consortium. The aforementioned balls were the brainchildren of the famous Dr. Max Koebner who, according to an unimpeachable source, oversaw their manufacture.
To the best of my knowledge (if anybody knows differently please post what you know) there was no thought of close tolerance testing then because pool balls of the past weren't viewed as something that had to be perfect. The same people who were buying phenolic balls still had access to Ivory (even until the early 80s) and ivory balls could get almost egg shaped and composition balls, also readily available, were in no way precise either.
Most all of the jobs at ABB Co. were unskilled labor jobs. In point, it didn't take an Einstein to build a pool ball. The took some gooey plastic and pushed it into a mold and let it dry. A few easy steps after that, they put them on the truck and shipped 'em.
There's an old joke from Albany that says that "from north of the City to south of it, the river bed of the Hudson River is made up entirely of rejected Hyatt balls."
Sorry, I didn't mean to babble.