How do you spray "dust" or "sand" onto a model?

Get some pastel chalks at an art supply/craft store, shave/sand off some dust, then apply with soft brush.

Art

Do you spray a dullcoat or something over it to seal the chalk on ? If not, wouldn' t it get smeared when you handled it ?

When you spray a clear coat over the pastel dust it usually diminishes the effect you are after. My advice is dont clear coat it with anything and be careful when you handle it. Cheers Kevin

you can also take Tamiya Buff....thin it about 75% to 80% thinner to 20%-25% paint, hold your airbrush a fair distance from the kit, and spray down the sides, slowly building up a dusty layer.....more so on the sides, and not as much on the top.

Ive heard light misting of Tamiya Buff color also works,,,,

Poly Scale Paints makes " Dust" it is very thin paint, basically it is a wash. I used it, and after it dries, it puts a layer of "Dust" on the item.