So I finally got to the hairspray and salt part. To be honest, I was quite reluctant to try this at first because of the fear ruining the models. Ok, maybe not ruin them, but failing at this would mean to start over and time is not what I have too much at hand being a father of a almost 1.5 year old son.
Anyhoo. Here is the detailed tutorial I used.
On top of the rust paint (described here) I airbrushed the hairspray (regular hairspray used with the wife unit's permission) and before it was dry I sprinkled salt on the spots where I wanted the rust effect to be. In hindsight I could have used more.
Note about hairspray: Clean your airbrush immediately. The stuff dries all gooey and sticky that's hard to clean later on.
Then I proceeded with the basecoat and zenithal highlighting for the armor parts. I only used salt on the armor plates since that's the only "painted" surface on the models of which to rust can show through. I used VMA Black Grey as the base coat. Gradually adding some VGC Bone White to it provided a nice warmer tone of grey for the following layers of highlights.
Then I made the big mistake. I rushed with the removal of the salt. The paint was not dry enough to withstand flowing water reacting with the hairspray. The 1st model (bonejack) lost significant batches of paint (not seen on any pics here... bad angles... gonna shoot one later) with the water flow and my anxious finger rubbing the salt away. My dear wife convinced that it looked ok despite the little accident. I let you guys judge that too :)
With the other models I carefully applied some warm water with an old drybrush and carefully removed the salt and made some scratches.
Note on drying time: Wait long enough before stripping off the salt
Then on to the edge highlighting the armor plates and the rust areas. I just added some more Bone White to the Black Grey until I was satisfied with the contrast. I'm going to give the armor plates a wash later on to pull back the highlight colors.
Next on the list (going with the feel of the Privateer Press style):
* Highlight the rust area with a darker shade
* Green areas
Comments? Suggestions? Feel free to use the box below.