Using washes/fiters on a tank with zimmerit

I recently did a Brummbar with zim. You're right about the weathering approach needing to be different as a result of the pattern. You can see how I did the full weathering process here: www.bpmodels.net/.../viewtopic.php

Thx for the replies. Any tips on how to compensate for weathered zimm? Maybe drybrush with a light colour?

The zimmerit's texture holds more shadow.  Artistically, you may want to compensate for the darker appearance of weathered zimmerit.  This is a preference thing, though

I use my own mix of thinner and artist's oils wash. I usually use a burnt or raw umber to bring out the texture in the zimm. i let that dry for at least a couple of days then do a dot filter with oils.