" ...records are more durable than one assumes."
Depending upon the vinyl pellets purchased, or recycled in the case of most U.S. pressing plants during the era mentioned; bleach and alcohol CAN affect the plasticizors used in the vinyl composition, even in weak mixtures. Plasticizors are usually based on dibasic fatty acids, which bleach will permeate.
I have had tests ran on various LP pressings (about 40 in all), and have found that most used plasticizors in the vinyl to make the pressing more flexible and easier to tool.
If sound quality is an issue, I think that I'd try either the discontinued and controlled Last Freon based "First" solution. The freon won't permeate the vinyl, yet will clean the vinyl well. The down side is that you will need to purchase a pair of industrial gloves that will protect you from the freon, which is thought of as a cancer causing agent by the state of California.
Depending upon the vinyl pellets purchased, or recycled in the case of most U.S. pressing plants during the era mentioned; bleach and alcohol CAN affect the plasticizors used in the vinyl composition, even in weak mixtures. Plasticizors are usually based on dibasic fatty acids, which bleach will permeate.
I have had tests ran on various LP pressings (about 40 in all), and have found that most used plasticizors in the vinyl to make the pressing more flexible and easier to tool.
If sound quality is an issue, I think that I'd try either the discontinued and controlled Last Freon based "First" solution. The freon won't permeate the vinyl, yet will clean the vinyl well. The down side is that you will need to purchase a pair of industrial gloves that will protect you from the freon, which is thought of as a cancer causing agent by the state of California.