Topic drift is great if it imparts this much information. I had never heard of PVA. Now I'll be tempted to touch the outside edge of some of my vinyl looking 78s with a soldering iron to see if they smell like buttermik.
Up untill now I have been using my Discwasher brush with their fluid on these records. So far no ill effects, but should I not do this.
Were you a chem or material science major? I was a EE major and I thought those courses were difficult and a PITA. More and more I am now wishing I payed more attention in them.
Thanks for the good info.
Whitneyville wrote:Phil, the things that make castile soap good on shellac make it not so good on vinyl. It isn't an aggressive cleaner, it leaves behind a residue (that acts as a groove lubricant) and it's not a great organic co-solvent which prevents it from attacking shellac or PVA, but prevents it from cleaning vinyl well, which we can literally use lye or sulfuric acid on. Information: What many people think are "vinyl" WWII and post WWII 78's are really polyvinylacetate or white glue thermoset records, also known colloquially as "buttermilk" records (as "buttermilk" buttons on shirts which scorched brown and smelled like burned buttermilk if touched with a hot iron). PVA records are often brightly colored but came in black too. They flex to a point, then they shatter like shellac, but early vinyl (PVC) records weren't as flexible either. This causes alot of confusion. Far more 78's were made from PVA than PVC. Early EP's, ELP's (45 RPM 12" discs) and 33 1/3 and the weird-Alice 16 2/3 RPM's can be PVA or PVC. Hint: The U.S. Army Signal/Service Corps 16 2/3 RPM "Voice Mail" records are all PVA, whether they be the tiny WWII 4.5" discs or the Korean War 5" to 5.5" discs. I have seen both on feeBay recently for $500+++. I'm trying to "nail down" what the Navy and Air Force did with their's. Excuse the topic drift.