Thanks Clint! And now we present the salt fading stage of this build. I imagine there are a number of ways to do this but it essentially uses salt crystals to form a random pattern mask to replicate the staining/wear you might find on an aircraft that's parked outside all of the time. Based on my own inconsistent results using this method, I claim no expertise and simply offer this as a document to this stage of the build.
Salt can only be used as a mask if it stays affixed to the model and we can accomplish that by using water, which dissolves salt. I like to perform this technique after a flat coat at the end of painting/weathering process for a couple of reasons. Number one is that subsequent clear coats, both flat and gloss tend to reduce the effect of the salt fading, sometimes to the point of making it disappear completely. Another is that water covers a flat coat uniformly and doesn't bead like it would on a glossy finish. Finally, salt residue, which can deposit itself unseen in the little nooks and crannies, can be flared into a white frost when an additional flat coat is applied.
I use rock salt that I crush to appropriate grain in a small ceramic dish. I like to use small salt crystals and try to avoid salt dust. Too much salt dust simply liquefies in water and can dry in a pool, preventing a random pattern to imparted to the treated surface.
Using a soft paint brush, I cover the area with a coat of water. Before the water dries, I sprinkle my salt crystals onto the wetted surface. Hopefully, the majority of the crystals should stick to the wet surface, otherwise it'll just bounce off.
I work across the model, wetting the surface and adding salt as I go. It's mostly random but I try to concentrate the salt a little more along the panel lines.
We let that dry completely. I just leave it on my modeling desk for a couple of hours.
Once this is dry, we can spray paint on it. I use a highly-thinned light grey or beige color, in this case Tamiya Deck Tan. It is thinned at a 12:1 thinner:paint ratio. This is the tricky part. It is very difficult to discern the effect as you are spraying. I mist the lighter color on in random swipes corresponding to the airflow over the wings and perpendicularly to airflow over the top of the fuselage. Too much and you get a chicken pox pattern that is difficult to correct so I tend to err on the side of too light.
After the paint is dry, you can remove the salt crystals. I usually brush off the big salt crystals by hand or with a stiff brush into a trash can. And then I'll spray down the area with water and then gently wipe off the remainder with a clean cloth. Hopefully you'll get some realistic wear patterns left behind. Here is the engine cowling after the salt fading.
The effect, I think, is pretty effective. I erred on the light side again and the result is a very subtle and almost imperceptible effect in most places. There was some inconsistency with my paint application and I had to dial down some of the more obvious streaks using Micromesh.
Here is the model in the light box after the salt fading. I'm going to let this completely dry out before going any further to make sure that no remaining salt frost gremlins remain.
