Just in case anyone doesn't know, you may want to pick up some talc because they are taking in it off the market. Apparently Johnson And Johnson failed to warn everyone it contains asbestos.

Hi Kevin,

This topic came up a couple of years ago, so I started looking at ways to buy plain old talc. It is available in bulk through chemical companies, *Bay, and other sources. It does take a bit of looking, and you have to be willing to buy more than you need "right now." I'd split the package with a peer...if I had one nearby.

J&J stopped using talc a couple of years ago in the US market (those "ads" you see on TV for "do you or a loved one have, or ever had uterine cancer? Call us now for class-action law suit..."). Their latest news was to drop it world-wide this year.

I'm not sure of the differences, but older threads here indicate zinc stearate (ZS) is a usable substitute.  Randy Smith jumped in one of those to mention he sells (sold?) ZS . I don't know how talc and ZS behave differently with respect to our intended uses. My really old Equate-brand Baby Powder (23 years old) did the job as expected the few times I used it. I still have quite a bit left in that old bottle, and may be able to discern what the components are. I do know I can't find the exact same packaged stuff. Same brand, different markings...so I wasn't going to buy a bottle to test since my kids manage their own backsides now.

Has anyone tried magnesium carbonate instead? L

Zinc stearate is much lighter than the other two. 

No that's a statistic that could push me to toss the old baby powder! I have an all-balsa model that looks like will take a bit of fillercoat to smooth out. Combine that with Mr. Brett's endorsement...now I'm sold.

Thanks gents.

I think I missed something...this stuff thins enough to be sprayed?

Zinc stearate is much lighter than the other two. 
Magnesium carbonate - density = 2.96 gr/cm3
Talc - density = 2.82 gr/cm3
Zinc stearate - density = 1.1 gr/cm3

Thanks Massimo.

Next question; why not bust zinc oxide. That’s what’s left when you remove stearic acid from zinc stearate. L

I think I missed something...this stuff thins enough to be sprayed?

Here's a thread from 2015 about zinc stearate.

Zinc stearate comes as a white powder, just like talcum powder.  You use it to make sanding sealer by mixing it with clear dope.

At that point it's -- sanding sealer.  Treat it as such: spray it on, brush it on, whatever.