The trombone designed by a committee

[Posaunus]

A friend sent me this article about the Martin "Committee" trombones from (apparently) 1939.
You may be interested:
https://docs.google.com/file/d/0B5-_7UC ... VSOTg/edit

[JohnL]

Hold on a minute...

the inner slide tubes are made of nickel steel?

[paulyg]

Makes sense... I have a committee deluxe that has some plating wear on the inners, and it looks like there are flecks of rust on them.

[imsevimse]

Hold on a minute...

the inner slide tubes are made of nickel steel?

I have that model and the slide is perfect. My horn is in mint condition.

/Tom

[JohnL]

Makes sense... I have a committee deluxe that has some plating wear on the inners, and it looks like there are flecks of rust on them.

Is it magnetic? Not a conclusive test (LOTS of nickel will make steel non-magnetic), but a start.

[timothy42b]

Makes sense... I have a committee deluxe that has some plating wear on the inners, and it looks like there are flecks of rust on them.

Is it magnetic? Not a conclusive test (LOTS of nickel will make steel non-magnetic), but a start.

If magnetic, then it's steel. If not, still could be steel. Although I would have thought any steel you could easily draw a tube with would be magnetic.

So, on to the second test. Hit it with a grinding wheel and check the color of the sparks. Steel should give you those characteristic bluish white fireworks clusters.

[BGuttman]

I used to own a Committee. The inner slide did not appear to be steel. It was too light. Steel the thickness of the metal would have been much heavier.

I would not be surprised if the inner was nickel silver (which is a copper alloy and contains no silver).

Sadly, I no longer own the instrument and can't test it for you.

[JohnL]

Most inner slide tubes on pro horns are nickel silver. Possibly a typo?

[timothy42b]

I used to own a Committee. The inner slide did not appear to be steel. It was too light. Steel the thickness of the metal would have been much heavier.

Are you sure?

This chart:
https://www.machinemfg.com/density-tabl ... um-alloys/

lists brass at density of 8.8 and steel at 7.8. If the steel is the same thickness, it should be lighter?

[CharlieB]

Many thanks to Posaunus for the great historic information.
It is possible that Martin inners could have been steel at one time, as steel /nickel alloys were available.
https://www.brighthubengineering.com/ma ... eel-alloy/

[BGuttman]

Nickel-iron alloys have been available for a long time as "stainless steel". Commonly used in surgical instruments and where corrosion is a problem.

The issue with using any iron alloy is the greater difficulty in drawing tubes (although most heat exchangers use stainless steel tubes) and the inner being quite rigid possibly creating a problem with the more flexible brass outer slide. It's also much harder and thus may make a rather strident tone.

Just noticed: I'm playing my Committee in my avatar

[Posaunus]

I used to own a Committee. The inner slide did not appear to be steel. It was too light. Steel the thickness of the metal would have been much heavier.

Steel – even with lots of nickel – is not denser than brass or "nickel silver."
Therefore a steel slide should not be any heavier than other slides with similar wall thickness.