weathering tyres

Well, I finally started up on my Peugeot 206 again and I'll have to weather the tyres. The car is to be weathered like it has just come in from a test run on a gravel leg. But how do I go about it to get a realistic look on the rubber tyres? Do I wash them with a brush first in the cavities and then dust with the airbrush on top or shall I just do them with the AB?
Any suggestions on how you do on this matter are welcome
best regards
Joel

One thing to use is dry pastel chalks, they`re available in arts stores. Scrape with your knife till you have a nice little pastel-dust pile, and use a wide,bigger-type modelbrush to dust the tires. It finds a way in everywere!
If you just want dirt on the roadcontact part of the tire ( not in the actual pattern) you can try some flat acrylic and roll the tire in this. then roll the tire in the pastelpowder. So, spread out the acrylic ( it`s the glue here) the spread ou the pastel on a paper until theres not much left,then roll tire. Get it?
Try and learn the technique on a scrap tire first.

I got it!
Thanks.
/Joel

I prefer airbrushing for the dust and a little paint brushing (washes and drybrushing) for the tread areas. Acrylic paint works well for this... - Mark

Hi Joel,
What I tend to do is use artists acrylics mixed with some talcum powder. I work it into the tread to give a caked on mudded appearance and use it thinned as a wash on the outside. I've also used a technique of mounting the wheel on a Dremmel, washing the centre with a thin mud mix, then spinning it at a slowish speed to give a radial splatter. Works quite well, although if not careful the splatter can go all over the place!