Simple Green to clean 78s? Think twice and be careful...

[Dischoard]

So I've been using Simple Green in my ultrasonic cleaner to clean vinyl lps, a mix of 1:30 with just a touch of dish soap and it's amazing!

So I decided to try some of my vinyl 78s from the 50s, the effects were just as amazing (but not more amazing than the amount of CRUD that collected at the bottom of my ultra sonic cleaner... and I had thought I had already cleaned them before).

So then we come to the fact that a shellac 78 was mixed in the bunch (I do 7 at a time and was on a roll). It came out so clean, I immediately played it and it sounded so nice and clear despite the surface scratches on this thing. Mind you, I'm playing it on a 1958 Magnavox with a Collaro turntable for testing.

So I thought "huh, I'll try a few more shellac records, nothing valuable, just to see what happens". Well if I didn't go and turn two records completely grey! I find that the Simple Green has no adverse affect on Columbia Reds, Victor Scrolls, early Bluebirds, or really early records in general. But look what it did to a late shellac RCA Victor release! Anyone have any idea what happened? It turns out that an ingredient of Simple Green is C9-11 Alcohols Ethoxylated (or whatever that means) which I didn't realize at first until the greying. Just wondering why it would affect just one particular type of shellac records and not others.

Anybody else ever try this and get this sort of reaction? And to think, at first the only reason I didn't want to try an ultrasonic cleaner is because I thought it may break the records. That hasn't even come close to happening, but boy that greying was astonishing to watch unfold as the record dried. Oddly enough, it still plays like a dream...

An un-phased Bluebird

And a totally greyed RCA Victor

[Inigo]

Could it be that the RCA is vinylite and not shellac? I've seen other records from this era with drop stains that clearly seemed the stains alcohol leaves on non compatible plastics... My late Canadian pressings of the Waller On The Ivories set are the culprit ones, and some late RCA pressings of Duke Ellington Victors in the 20-1500 series.
The thing is that they used slate mixture like in standard 78s, thus the weight and the feeling and clunking sound as if they were real shellac, despite a clearly different touch. But they used vinylite (or a part a at least) instead of pure shellac for a binding agent in the mixture, and this is what seems to be sensitive to alcohol. Nevertheless, shellac is also sensitive to alcohol... isn't it? Anyway, since the early forties they were using several mixtures that clearly were no more the same as in the previous records.

[Dischoard]

since the early forties they were using several mixtures that clearly were no more the same as in the previous records.

Clearly! I don't know about the vinylite, I cleaned a whole stack of Quality records from Canada that say "pressed on Metrolite" on the label, they came out just fine. But again I think those are really just a type of vinyl as they're flexible, not like you describe. Yeah, whatever RCA Victor was using past 20-3000 appears to be different stuff and it does not like the Simple Green!

[recordmaker]

As shellac was always expensive there were several attempts to substitute for it.
I have details of one formula using Vinsol and PVA plastic along with mineral filler Via EMI in the later 40s early 50s.

Vinsol resin is a dark reddish-brown, high melting-point, thermoplastic natural resin, extracted from pinewood stumps and refined through a special process.

some cellulose plastics were used with mineral fillers in the 1930s but most failed for various reasons

This material would have a similar feel and weight of shellac pressings but would have different reaction to certain solvents from shellac but are more soluble than vinyl which resists most common solvents.

Shellac based records will dissolve in most acholic solvents ,varnish , i.e. French polish, is made by dissolving shellac in alcohol, (ethanol ) so I would avoid any of this family of solvents in contact with shellac pressings.

[Inigo]

Metrolite was the compound used by MGM records in late forties. As was Deccalite used by Decca, etc.

[epigramophone]

Shellac based records will dissolve in most acholic solvents ,varnish , i.e. French polish, is made by dissolving shellac in alcohol, (ethanol ) so I would avoid any of this family of solvents in contact with shellac pressings.

On one of the many antique restoration programmes on UK TV someone crushed a record and dissolved it. They then used the resulting black solution to touch up the finish on a Chinese lacquer cabinet. Fortunately the record was a common Regal-Zonophone.