is it safe to clean records with isopropanol ?

I use what Opus uses, except I add a few drops of a non-ionized detergent per liter, Triton X100 is one example. I can say I have had no issues, but how would one know, unless the damage was rapid and gross? One is hardly doing a controlled study of record cleaners. Safe to say that the LP does not dissolve before my eyes.

I did once compare the above solution to the enzyme-based cleaners sold by Walker, which of course involve no alcohol. I cleaned side A of one of my favorite LPs with the Walker Audio stuff and side B with my standard solution (using a VPI HW17 machine). The results were very very slightly in favor of the Walker enzymes, but I concluded that my standard solution was faster and simpler. So I stuck with the latter, but the results suggest that there was no gross damage done by either method. That's the limited evidence I have to go on.

"I can say I have had no issues, but how would one know, unless the damage was rapid and gross?" True...and I agree with you, Lew. The way I see it, as an approximately 70 year old fart, my hearing is a fair cry from what it used to be, though I'm still enjoying what I AM hearing, and as long as that's so, I'm good. Best wishes with the hope you're enjoying the music too!

So what does isopropyl alcohol do that a mild soap / detergent solution doesn't? When I want to remove grease, dirt, slime, residues and other contaminants, I use soap and water and rinse with clean water. What does alcohol do better.

I started to clean stubborn dirty LPs with a 9.6 % ammonia solution. A bit inconvenient to apply so a careful procedure is required, but the cleaning results are amazing.

I put it directly on the vinyl, brush the discs for about five minutes, then vacuum it off. Final cleaning with my standard solution, vacuuming, and that's it.

Reduction off crackle could be dramatic.

"So what does isopropyl alcohol do that a mild soap / detergent solution doesn't? When I want to remove grease, dirt, slime, residues and other contaminants, I use soap and water and rinse with clean water. What does alcohol do better?"

That's a very good question Bpoletti-the answer to which, I believe, is nothing.

I keep a bit of isopropyl around and might use it to clean maybe one in maybe 50 or 60 records at most, mainly those that have something very sticky on them. Apart from that, my view on isopropyl is that it is simply not very good at cleaning records and doesn't contribute much to the process at all. It is not a very effective cleaning agent.