I had forgotten that talc is now hard to find, because of its proven toxicity, not only because it physically resembles anthrax spores. If one must use something similar, what about the current version of baby powder? I personally don't think it's helpful when responders try to talk the OP out of the idea behind his or her question, but what is so terrible about a little squeak at start-up? And are there real studies that show talc or the like extends belt life? I no longer own or use a belt-driven turntable, but I did own several in my past audio life, and I never heard a belt squeak even without the benefit of talc. Apologies for doing the very thing I have an adversion to, trying to talk you out of talc, in this case.
Turntable Belt Care—talc or corn starch?
While servicing my belt driven turntable recently I discovered my 15 year old container of unscented talcum powder had disappeared. While shopping for more, I found that drug store talcum powder isn’t really talcum powder anymore. Because of cancer concerns, the talc has been replaced with corn starch. For our needs, both can be considered a lubricant.
VPI said using corn starch on the belt is okay, just make sure to wipe any grease off of the belt, pulley and platter rim before you powder and install the belt.
In the past some manufacturers put talc in the bag with the belt. Anthrax fears ended that.
I was able to find real talcum powder online and some dive/surf shops have it (to ease donning wetsuits).
If you’ve forgotten how to powder the belt, put some powder in a baggie with the belt and shake, take the belt out, shake off the excess powder and reinstall.
Why do this? The powder allows the belt to slip slightly on start-up acting like a clutch, reducing/eliminating belt noise and extending belt life.
Maybe it’s just me, but I prefer using talc (a mineral) over cornstarch (a food). Perhaps it’s that talc isn’t water soluble so it’s unaffected by humidity or moisture like corn starch? Is that really a concern? Or that manufacturers have recommended using talc in the past and not the more common corn starch?
Either way, now you’re aware. If even you care.
And if you have a direct, magnetic or idler arm turntable, no belt, no worries—you can stay out of your wife’s kitchen domain looking for corn starch. I recommend that like I recommend talc.