First up, after undercoating the minis grey, I airbrushed a bright silver over all five of the models.
The next step, for which I don't have any photos, consisted of a thin layer of varnish (to protect the underlying metalwork) and once that was dry, I sprayed each part with hairspray and sprinkled over some salt. I then airbrushed the whole lot black. This will increase the definition of the weathering at the end of the process.
Once that has dried, its time to start painting the colours properly. So out came the greys and I airbrushed a gradient starting from dark grey and working up to a light grey at the top of the miniature. Here is a WIP shot of that process
Once the gradient was complete and the paint totally dry, I attacked the model with a toothbrush and some warm water. This knocks off and dissolves the salt added earlier and creates bare bits of metal (from stage 1) in a random pattern on the model. The following photos show the Justicar with most of the model glued together and few metallic bits painted, but it shows the battered armour quite well...
Each one of those dinks in the armour needs to be shaded and highlighted, and I need to add oil stains and other muck and grime. Hopefully this should contrast well with the tabard and shoulderpad heraldry which I have yet to paint... I am not 100% satisfied so far, but will try and finish these over the next couple of weeks and make up my mind if I want to use the technique on the rest of the army.
I do need to get some proper photos too!