Painting of exhaust tubes in SPAD , SE5?

[Romani]

A stupid question, but had to be asked.

In the profiles and museum photos the tubes appear to be painted black, but if they were anything like my old motorbike exhaust, shouldn't they be overheated metal chocolate rusty ? I am under the impression that the curved pipe that goes out of the engine is copper and doesn't rust, but the long mufflers are steel and they do.

So what it is? gun metal? painted black? rust all over and blackened with soot at the end?

I've always seen them represented as being rusty on the ends. My guess is that museums and profiles might try to show machines in a more pristine state. I'd go for the rusty look myself if I wanted to be accurate. I'm sure one of our resident experts will offer the last word on this.

Brian da Basher

[Old Man]

I believe the exhausts were made of a copper alloy; the Memorial Flight people restored their S.P.A.D. 13 with exhausts of that material, and I gather they were working with original specifications pretty religiously. Copper is easy to work, and that would be an advantage at a time when production was being hurriedly expanded. I have no idea about the S.E.5a, never having looked into the machine with an eye to modeling one, but owing to the similarity of engines, suspect the same material might have been used. The Allies had good stocks of copper, but it seems to have been short with the Central Powers, and I imagine accordingly they used steel.

I handled the exhausts of my S.P.A.D. by painting the tubes first with a mix of copper and dark brown enamel, about two to one, which gave a tone like a used but still fairly bright copper coin. I went over this with acrylic washes of brown, black-brown, and maroon, with the latter two colors heavier where the exhausts pipes emerge from the cylinders, and the black brown also at the area around the outlet. I liked the effect, but a straight dark red-brown with a single black wash would probably do an adequate representation. When heated, copper tends to pick up a dark red scale, which the maroon was intended to represent, and why I recommend a certain reddish cast to the finish where the thing would have been hottest.

[mgtaylor]

I'd have to agree with you the origianal factory welded exhausts would have had to be steel and or copper and most certainly would have instantly weathered with moisture and engine exhuast heat. Iam almost embrassded by an early attempt back into the hobby with the Revel 1/28 Spad and played with a small collection of MM Metalizer colors. I have a set of "Rust-All" now which I think I will experiment with the next time to give it a weathered look. http://www.imagestation.com/mypictur...1.jpg&caption=

I will try to post the pic but I don't know how guys are able to get their pic posts to stay on the board just yet?

[StephenLawson]

Greetings all; For a reference see the SE 5a Datafile Special.

RAF SE 5a by J.M. Bruce, Datafile Special, Windsock pub.1993.

There are some fine colour shots of the Hendon SE 5a. First with a Hispano Suiza and then with the Wolseley Viper. The exhuast was a blackened metal with oxidized (flat light red) header connections. The Black was the result of a mild acid treatment that protected the metal from rust. Pure copper was probably not used. More like a type of tin with a copper base. The fittings attached to the fuselage were painted black. I tend to use Testors Model Master - burned iron. It has a nice copper base to it.

[Ross_Moorhouse]

As one who used to make aircraft exhaust systems for a living i will offer some advise and observations.

Exhausts also suffer discoloration from the heat that is passed through them. Where the exhausts are closet to the engine I would do these as a darkish grey if you have painted the exhaust with Testors Model Master - burned iron. Also make that darkish grey a matt colour. This will help to show the layers of metal that start to flake off. Also this happens ay clamping points of an exhaust pipe. This is because it becomes a hot spot and also it could be from 2 metals that are not the same causing an electrolytic reaction. The heat helps with the process.

Ends of exhausts can be weathered to reflect how the engine is running. Either rich or lean. Use black weathering powders for a rich running engine. And a grey, even light grey, color for when it is has been running lean.

Weather the exhausts with rust colored weathering powders. Do this very lightly. This will give the affect of the hot pipes having cooled and some rust has formed in places…

All the weathering as above should be very subtle.

Some examples to help from the real thing… Taken from
Rosebuds site http://www.earlyaviator.com/archive1.htm

You can see a discoloration in this pipes ion this Spad… the light color would indicate a hot spot.

Shuttleworths SE5a. Again you wills ee some discoloration this time on the insides of the pipe near the end. Taken from http://www.airliners.net/search/phot...nct_entry=true