One thing to note is that for the flying surfaces (wings/tails) and fuselage underside, the streaks were applied in the direction of the airflow. The beauty is that if you're unhappy with it, simply use the Tamiya Acrylic thinner to clean it up and start again.

Experiment with it and try different applications to get the desired results. I typically will use a combination of my finger and a paper towel. Also, rubbing with a paper towel lightly soaked in Tamiya Acrylic thinner can help as well. Note that in some cases, additional pigment was added to the same area to get the desired look if it came out too light. It's a pretty arbitrary and random process, but utilizing some reference photos, you can get an idea of where these kind of leaks occurred and how heavily along the aircraft. This was repeated as necessary to get the desired look.

From there, I used my finger to streak/rub the applied pigment back in the direction of the airflow. Some pigment was applied to the surface in a desired location along a panel line using a paint brush. This was primarily done using Folkart Raw Umber acrylic pigment. With the control surface fading completed, I went on to applying some oil stains and streaks. Note that the same was done on the underside with Model Master 'Flat Gull Gray' used as the lighter color. I was looking for a slight color change and a highlight effect on the ribs. The intention was for it to be subtle, so a good portion of the applied paint was burnished away. From there, the tape was removed and the surfaces were burnished down with a Scotch-Brite pad until I got the look I was going for. Only 1 to 2 passes were made in this case as I was looking for a subtle effect on the surface. The beauty with the thin paint is that if you want more color, then simply perform another pass and repeat until the desired shade is achieved. The model features some scale ribbing that would be apparent from a fabric covered surface, so the raised ribs were airbrushed over.

From there, the control surfaces were masked off and the thinned paint was airbrushed over the control surface details. To achieve the lighter shade of 'Olive Drab,' I used Model Master 'Armor Sand' thinned down with Enamel Thinner to the consistency of dirty thinner. I wanted to simulate this on the model by airbrushing a lighter shade of color over the molded ribbing on the model. When looking at pictures of P-39 Airacobras from WWII, it was pretty apparent that the canvas covered control surfaces most definitely faded over time. This is why I like to use a lacquer clear coat generally as most any type of paint will go over it in the weathering process and protect the underlying paint job underneath. I regularly leverage plastic model paints such as Testors Model Master and the like in this process as well, but it's important first to have a good solid paint foundation for the application of the weathering. In terms of the tools, I like to use a selection of acrylic pigments along with Tamiya Acrylic thinner for washes and oil streaks (you could conceivably use tamiya acrylic paint too) and a Grex airbrush (I love these airbrushes!) for fading and shading, and a fine Scotch-Brite pad for blending it all together. This is important to note because we will never be able to replicate all those years of intense exposure to the elements, we can only simulate it through the use of different tools and techniques to artificially make the model look aged. The weathering process is about taking a pristine built model and simulating years of use and abuse in the field to add realism.

E flite warbirds