After priming and painting the road wheels plus the end caps I finish the drive side of the road wheel with a mixture of Humbrol 11 and Model Master metalizer stainless steel.
I add more texture to the road wheels of the King Tiger by using Liquitex heavy medium acrylic and more baking soda, I stipple the entire area leaving some bare spots and sprinkle the baking soda on top. The other pictures show some preshading under the primer on the chassis under a coat of primer.
After mixing some AK pigments with some plaster, I use both the dark mud wash and some dabbing of the plaster mix on both the road wheels and the chassis. After setting for a week or so , I coat with some future to protect the area and to seal in the detail.
After letting the Future dry I add some acrylic gel again , stippling and adding Woodland Scenics snow and baking soda. I again leave some bare spots for some more detail painting after everything dries. As you can see by the photo you have a wonderful sheen of frozen muck on the bottom.
Next step will be the tracks and outer road wheels and blending it all together.