How to Create Dirty Oil Streaks and Stains
I was recently asked what did I use to create those realistic oil/gas stains on my corsair. It's actually pretty simple so let me show you how.
I'm sure there are other methods out there that accomplish the same effect and this one justa happens to work for me.
Here's what you need:
Ammo of Mig Fresh Oil Stains (or similar product)
White Spirit for enamels
Dark brown pastel
Airbrush or other air source
I usually start with about 3 parts Mig Oil to 2 parts white spirit, but you can vary the ratio to suit your preference. I'll then scrape a bit of the pastel dust into the mixture- light amounts for light contamination, heavy for more extreme dirt. You just have to put yourself in the envirronment your subject is subjected to.
Use your brush to thoroughly mix the slurry and dab a spot onto the affected area of your model. This is usually along panel lines, break lines, hydraulic line connectors, engine casings, cylinder heads, etc
Take a clean, dry airbrush and gently spray air onto your dabs gently guiding them in the direction of the aerodynamic airflow.
The results are pretty cool as you can see in the image below.