So the next thing to do is to place salt where you want the rust to show through. Now thats a lot easier said than done and it took some experimentation to get everything going the way I wanted it to. Basically you have to wet the area and then sprinkle the salt on. I found that this left a very thin coating of salt that the paint could soak through. I used rather fine salt and I have seen most other people use coarser grains. However I noticed that if I coated a larger area and then using my brush to apply a drop of water to this I could manipulate the salt nicely and gather it together into some thick and well shapped clumps. It took a lot longer for the salt to dry but it was worth it in the end I think. You have to be careful where you place the salt so that the weathering looks natural and I am really still learning this. Its easy to see tanks and how they get worn. There are awesome guides explaining how to use this technique. However nobody has, that I have seen, done this for Warjacks before. The technique has been used but never in a way I feel captures exactly what has been done on some of those beautiful scale tanks. I definitely won't manage it for a long time yet either! So with the salt dried, which I left overnight, I then sprayed the model as gently as possible with the basecoat. This is going to be a grey for my Mercenaries. I was worried that the pressure of the airbrush might knock off the salt but thankfully it didn't. I was able to coat the model easily without any problems. The extra water on the salt gave it a good strong bond to the model. It was pretty difficult to actually knock it off when I needed to! I also tried to paint the model a little with the salt left on. The spear I gave a rime of salt to and I painted the point of the spear in silver to see if it would soak under the salt or just be a pain in general to paint.
So here is what I have once the salt has been knocked off. I think the effect is interesting but not as of yet perfect. Having now done this I am left with a few problems. How can I justify such harsh rusted patches and yet still have untarnished or not as tarnished metal elsewhere. I have a few more tchniques that this 'jack is the test piece for but I have to collect a few more materials to try them all out. I can at least say that the salt weathering achieved exactly what I wanted it to. It isn't perfect and I know what I will do better for next time.