Boltgun Metal then a wash of magic mud works well.

They're mostly a few rounds of drybrushed metallics/wait for it to dry/wash. Bear in mind that I'm mostly still using the round pots from the Nineties, so the colours won't match up perfectly with modern ones.

For the robot's silvery parts:
Black undercoat (spray primer from B&Q).
Drybrush of Boltgun, some parts picked out in bronze.
At least two hours for the metallic paint to dry before the wash.
Fairly thick wash of black paint, chestnut ink, brown ink and water - not sure on the proportions, though.
Some parts then had a light drybrush of either boltgun or silver.

The brassy face on the front had a thorough drybrush of gold, then repeated washes/glazes of chestnut ink and brown ink with a bit of bestial brown mixed in to thicken it up.

The silver on the Exo Armour was repeated drybrush silver followed by chaos black/water wash, I think about three rounds, finally followed by pure silver to highlight. No chestnut or brown for this, to keep it looking cleaner.

The gold parts were similar to the robot, but with the base coat of gold painted on rather than drybrushed. A pale brown base coat under the gold can help make the gold look more solid, but that's probably irrelevant for Kans...

Ian

Yes, that should work quite well, possibly followed by a thinner wash of some kind of really dark brown/black to look like oil in the crevices.

On the subject of oil, a bit of black mixed with green, brown and some gloss varnish can work really well for oil leaks:

http://www.warseer.com/forums/showthread.php?p=1000843#post1000843

Ian

This months White Dwarf has a painting masterclass which includes several things, including verdigris and oil stains on Ork vehicles and armour.

Cheers Ian.

@JC - Cheers, I may have to pick that up (read it at the club).