Burnished pattern type?

[Glenn Gordon]

Hi,

Can anyone tell if this classic burnishing pattern has a particular style name or term used to describe it?

Does it serve a functional purpose? Or is it aesthetic only?

In regard to its use on aircraft, is it used on both aluminum and stainless steel?

Thanks,
Glenn

[FlyingRon]

It's called engine turning or jewelling. Purely decorative. The pattern is also described as "Perlée" given that it looks like little pearls or "."guilloché." Essentially, it's made by repeatedly moving a metal pad/brush over and over into the sheet metal with an appropriate abrasive. If you ever seen the Jimmy Stuart movie the "Sprit of St. Louis" you'll see a brief shot of them doing the turning on the plane.

See about 40 seconds into this clip from the movie: https://www.youtube.com/watch?v=El8q0gg54Dk

[Glenn Gordon]

Thanks for the info!

Is it used on both aluminum and stainless steel?

[Mike Switzer]

It used to be done a lot on higher end firearms, particularly internal parts of double guns.

[FlyingRon]

It used to be done a lot on higher end firearms, particularly internal parts of double guns.

Clocks and watches sometimes have it aas well.

[FlyingRon]

Thanks for the info!

Is it used on both aluminum and stainless steel?

Easiest to do on something soft, but it can be done to any metal with different tools/abrasives.

[martymayes]

Can anyone tell if this classic burnishing pattern has a particular style name or term used to describe it?

HI Glenn, when I was a kid we called that a brushed finish. Or specifically in this case, circular brushed finish. There are methods for making other that a circular pattern.

Rose Engine Turning, as done on a Rose engine lathe is a somewhat complex process that uses a very specialized machine. You can search on YouTube for "Rose Engine Turning" and there are some videos on how that is done. They would scoff at a brushed finish on the engine cowl being called "engine turning"