Yep, it's Talcum Powder and just removing the baby powder smell is worth the world. remember, the powder is just a weave filler and most of it is sanded off, guess what my shop floor looks like when I'm doing it!! Foot prints going in and out too. Nothing like a shop smelling like you just powdered a baby butt. After sanding I leave my planes for several days and the finish gets harder and harder. I haven't seen any primer that didn't stick to it. I use Klass Kote paint, they have there own primer but I just buy mine off the shelf at the hardware store. KK tells you what works best and what you can use. If you have the money then it's best to always use the products from one company. KK thins to a 50/50 mix and goes a long way. I use a cheap HVLP spray gun I buy at Harbor Freight, about 12 bucks when on sale. You can even use foam brushes with it. I just buy a gallon of the cheap thinner at teh hardware too. That way I don't sting out when cleaning my gun. Good way to glass and a good paint to use.
TWN, last time I glassed I closed the door to my shop, when I was finished I discovered I haven't felt like that sense the 70s!!! I was a total wreck!!