Once all the details were painted and the metals were given a light wash of GW Nuln Oil and then the entire model was given a coat of Klear
Once the Klear was dry the entire tank is given a light wash of burnt umber oil thinned down with white spirit
The tank was then left for 12 hours to allow the oil paint to dry completely. Then using AK Interactive Rust Streaks started to add rust spots and streaks taking in to accout there water may have built up and caused rusting and where rusty water might have dripped down the side of the tank.
Then the tank was given another coat of Klear, once dry all the lenses were painted soot on exhausts etc and mud splatters using AK Interactive Dark Mud. If you dont mind a shiney tank you could assume this was finished.
I however like my tanks to be matte, in my mind a real fighting vehicle would be matte from the dust grime etc but that is personal preference. So using Daler and Rowney Soluble Matte Varnish thinned 4:1 Varnish/White Spirit I gave the tank an airbrushed coat of matte varnish.