Exhaust markings and gun smoke

thanks benzdoc and qmiester both of your comments really helped.

J Man, first of all you want to have an idea of what the shape of the stain is going to be, and give yourself a little help by drawing it on the model first with a fine pencil. Then you want to use paint that is very thin, maybe 10% paint or less. As for the color, I think what qmeister said is right on. Especially if he has firsthand knowledge of working on aircraft. that is too awesome! But then the main technique is to start at the beginning of the stain, and as you move back, slightly pull the aribrush back, so that it widens out and gets more "foggy" Of course this is where your reference material becomes invaluable. (by the way, I learned it from the much criticized Squadron Encyclopedia)

I hope this helped a little. Best wishes

Exhaust stains can run from black to an almost white gray. Old radial mechanics (of which I count myself as one) keep an eye on exhaust stains as a clue to how the carberator mixture is operating. An all black stain is carbon residue indicating the engine is running in a rich condition resulting in excessive fuel consumption and slight loss in power while grayish white stain indicates an extremely lean condition which results in high cylinder head temps and very possibly the destruction of the pistons.
Ideally, you try to adjust the carberator mixture settings to give a light gray exhaust stain (light gull grey I think). Probably the best way to understand is to look at what is left after a camp fire is put out. The black coals are incompletely burnt fuel (carbon) while the white ashes a completly burned fuel.

On an aircraft that is washed regularly and don't have stains on the nacelle or fuselage, you end up peering into the inside of the exhaust pipe or stack to see what color it is.

Yes I have an airbrush and what technique is that?

J man, do you have an airbrush? You can make a convincing exhaust stain with one, in fact I think that alot of people use that for exhaust stains. Especially since most ww2 vintage aircraft (like your mustang) have a stain that is not just one color. I plan on using this technique on my current project, but i am still learning too.

hey swanny i found it and it will definitely help my weathering of the plane. I just didn't really see any thing that i wanted like exhaust or gun smoke. but it will help me to weather the plane though so thanks.

hi swanny
just took a look on your site...that salt technique looks amazing!!
regards,
nick

Hey swanny i didn't find it under your link.

Click on the link in my signiture and look for "The Basics of Weathering" or "Salt Chipping and Raised Panel Lines". Both cover the techniques for exhaust stains and gun blasts. A stick of pastel chalk costs $0.73 here.

J-man,

It varied upon the type of aircraft and effect you wanted. Black to shades of dark and light grey. E-mail me so I can send you a couple pictures to show the differences.

thanks Melgyver that is interesting. What color do you use to make them?

I have used the "dry brush" technique with regular enamel paints. A little practice and it's easy. You can use water base and if you don't like it just wipe it off.

Th ank you all for your suggestions. To answer some of your questions/comments. Thanks Dick McC i will mess around with that and see if I like it. philipowitsch My family doesn't drink tee and most of us Americans use are stove to keep it warm so we don't have those candle things, I do like your mustang you did an excellent job on it. And that is why I am asking, is because I got a 1/24 scale P-51D for Christmas. And to djmodels1999 I have both enamils and acrylics, no I don't smoke, but could a BBQ grill's ashes also work? Thank you all for the help.

You can use pencil lead. I cut down a pencil to where the lead is exposed and scrape it with the back edge of an X-Acto knife blade over a plastic lid. Then, using either a old, cut off paint brush or a Q-Tip, rub the carbon where I want it on the plane. I like the results and you can't get much cheaper!

J-man,

I have used candles soot for exhaust staining. Do you have these little candles in the states usually used for keeping teapots hot? I take the metal pot in which they come, light the candle and collect the soot. Then brush (lightly!) the soot where you want the staining. It costs nearly nothing, but be careful, its oily. You can see pics of that in my post from yesterday (Mustang Photos).
Hope that might help a bit
Gerald

What have you got? Enamels, acrylics? If you smoke, cigarette ash can give some nice effects, a bit like pastel powders...