Hey guys, I need some help. I’m building Hasegawa’s P-38J and I’m not sure how to go about painting the exhaust. The bird I’m replicating comes from the Pacific Theater, so I want it to look a little tired. Thanks!
Not a 38 turbo charger, but shows some of the wear. 
If you look close, you can see how the paint is discolored around the turbo charger. On a bare metal, I think I have seen pictures with exhaust stains on the booms.
The few pics I’ve seen of wartime birds show very heavy staining. I’d have a hard time saying what color the staining is but if you take into account that most US bases used the same fuel (provided it was available) you can pattern the color off of just about any other a/c in that theater. Here is a shot I found showing very heavy just aft of the SC. The light portion is very light gray and usually surrounded by light tan then darker colors like brown.
and i believe that that aircraft “YIPPEE” is a bright red
It depends on if the booms are painted or bare metal. The booms that were painted tended to have light grey/tan streaks. Bare metal finishes usally have more a burnt metal look not really a staining but a discoloration of the metal. Much harder to duplicate than the streaks on the painted booms. You are correct there DURR Yippee was the 5000 production plane and was painted overall gloss red. Here is an example of staining on a F 5. On the color photos of Yippee I have the booms are stained with black streaks. Very unusual.
Soulcrusher
Soulcrusher-
Great photo comparison, thanks for sharing that one! Gonna have to remember it when I do my photorecon.
Your welcome Daywalker. I always love to share my photo stash with fellow forum members. I have a pretty good collection of color photos for recon Lightning’s. Both F4 in purple haze and F5 in british Azure Blue and a darker blue as seen in the photo. From most of the color photos I have it looks like the blue shades discolored more than the greens or the NMF planes as you can see. Turning a tan/grey all the way down the boom and around the turbo. It makes for a different looking lightning. Here is my first effort at duplicating it with the old Monogram bear of a kit. Here is a cool color photo of Yippee showing unusual black stains.
Soulcrusher
What colors did you use for the exhaust staining on that particular bird?
The color of the exhaust stains actually depends on the mixture (fuel/air) setting. A full rich mixture will give you black stains (really black stains). As you lean the mixture, the exhaust stains begin to lighten going from black, to dark gray, then light grey and then to white.The stains become brownish when oil is being burned and is more pronounced on radial engines (it’s the nature of the beast - “if you ain’t leaking oil, you’re out of oil” is the basic rule of thumb).
Mechanics use the color of the stains to determine if the carb or fuel injection system is working properly - since most of the time in flight the mixture is set in the lean (or auto lean in military a/c), you want to see light grey stains - that indicates the mixture is set properly. Black stains in the auto rich settings indicate the mixture is set too rich, while white stains indicate the mixture is too lean (which means you may have additional problems - the leaner the mixture, the hotter the burn - very lean mixtures can and will burn/melt the pistons out of an engine).
I custom mixed up a light tan with some light grey and tried to match it by eye to the pictures I had. The color varies greatly from plane to plane. If you have pictures of the actual aircraft you are doing that is the best. If there are no pictures then you can use your own judgement and have some freedom to stain it the way you think it looks cool.
Soulcrusher
Thanks for all the info on the staining, guys. Those of you who’ve built a Lightning, what process did you use to actually paint the supercharger?? I’m a little nervous about that…