Weathering Question

[TexDoc]

I want to weather a repair shop/gas station. Normally I use powers and dry brushing, maybe other stuff, but this time I want to airbrush a general weathering, like the accumulation of dust & dirt and age from sitting on the corner for the last forty years... Any suggestions of colors to mix. I use water based paints like Model Flex mostly.
Thanks for the input (I hope)

 

[doctorwayne]

The colour of the weathering will depend on the site where the building is located, and on the colour of the building itself. Some colours just don't "look right" when combined on the wrong base colour. Can you post a picture of the building?
Other factors affecting how a structure weathers will include the materials that it's built from, and its design: a large overhanging roof will protect a lot more wall area than one that only projects a few inches.
As with any weathering, thin your paint severely: it's much easier to apply successive coats to build up the weathering effect than it is to remove too heavy an application.

Wayne

 

[Biased turkey]

Why not use a wash instead of airbrushing ?

Jacques

 

[sumpter250]

Airbrush: Applies an overall surface coloring, good for fading, and dust/dirt buildup. Airbrushing "coats".

Wash: Applies a thinned color that will tend to fill "low" areas, like the space between boards, or corners like between edges of braces or trim and siding. Washes "fill".

Drybrushing: Applies almost dry paint by "scrubbing" the color off the brush. This accentuates raised areas, like rivets, edges of angle braces, edges of corners, etc..Drybrushing "highlights" the small details.

Actually, a combination of all three methods will provide the greatest control of the overall effect of weathering. The most logical order would be wash first, to fill in. Drybrush, to accentuate. Airbrush, to coat with dust/dirt, and to lastly, dull the finish. When drybrushing over decals, take care not to accentuate the edges of the decal film. This isn't as important when drybrushing "body color" over the decal, to "fade" it, as it is when adding dirt streaks.
In the end, ask what weathering am I applying? Is it dirt deposits from rain? (wash) Is it wear damage from scrapes or wind blown abrasives? (drybrush) Is it "color" that sticks to the structure, like windborn dust, or pollen? (airbrush) or , is it sun damage, fading? (airbrush)
Regardless of the procedure, you will have to practice. When you see the "toy trains" on sale?, think "practice project for one, or more, of the weathering techniques"

 

[spitfire]

It also depends on the material your structure is made of.

If brick, it will darken over the years due to soot, smoke, exhaust in the air. The effect will be very even all over the structure, so you would probably just use a darker paint to begin with.

If wood, the ravages of time will attack the paint. It will be peeling, or completely worn away, leaving darkend wood underneath. Obviously, this would not be even, and the greatest effect will be on the "weather side" of the building (around here that's west), and in areas where water would pool. Brush painting works best here - although some people use a resist (like rubber cement or airbrush masking) in spots here and there before they paint, then peel off the resist leaving bare wood. But the bare wood should also be weathered. Alcohol/india ink stain works perfectly.

If metal, the effects of time and weathering are rust. Again, you have to think about where water will pool, as those are the areas that get the most damage. Also, streaks of rusty water run off the metal, usually onto concrete, or whatever you have supporting the metal. This is where weathering powders, and washes come in. First add the powder, then with a fine brush dipped in alcohol, allow the alcohol to run down the sides, following gravity.

A gas station could easily have all of these materials present, so you should probably use a combination of techniques.

Where airbrushing comes in super handy is around the bases of buildings. Dust and dirt get kicked up from the ground by wind and rain, and leave a thin coating at the very bottom.

Hope this helps.

Val