Hi guys, this post is inspired by the recent posts where several modelers have said that they've used baking soda/sodium bicarbonate for snow in their dioramas!
PLEASE---DO NOT USE BAKING SODA FOR SNOW!!!!
Sodium bicarbonate is an antacid--too chemically unstable and reactive to be used for modelling applications! It can be used to relieve stomach problems, clean both contact lenses and silver tarnish, and is one of the ingredients in crack cocaine! BUT DON'T USE IT FOR MODELLING!
I had a nightmare of an experience with it that ruined half of my collection in the late 80's. I used to use it like a "magic powder" and used it to simulate everything from mud to rust to snow. A few years afterwards, I started noticing a gunky, oily, resinous gunk on all the surfaces where it had been used; tracks, mufflers, etc--I mean, it was GROSS!
I couldn't figure out what the heck it was, so I got on the phone. I called several paint companies, hardware stores (problems with the lacquers? Thinners?!), and finally called Arm & Hammer, makers of "Baking Soda". They said that what was most likely happening was that the sodium bicarbonate was breaking down because of he chemical interaction of the laquers and/or enamels that it was in contact and/or combined with, and that ooze was the by-product of it. Half of my collection was RUINED! There was no way to save it!
I know there will be guys posting here with testimonials saying that they've used baking soda for years and have had no bad experiences, yadda, yadda, yadda...LUCKY YOU! I'm just telling you what happened to ME, and saying "YOU"VE BEEN WARNED!" If you want to take your chances, well, I hope you're "lucky" too!
IN closing, I'd suggest using unscented talcum powder instead, or one of the many available snow products out there. Better safe than sorry!