Can anyone here point me to a good source for buying nickel or silver tubing in dimensions suitable for lining a head joint and making a tuning slide? I recently bought an antique Clementi flute that needs a new head lining and tuning slide. I also have a Fentum that I have been restoring whose head lining and tuning slide are fine, but it needs an outer sleeve for the visible part of the tuning slide. If I can find a source for such materials in small quantities I was thinking of having a go at this job myself, as a bit of a learning experience. Any suggestions would be much appreciated! Thanks!
metalsmith.co.uk has nickel silver tubing suitable for slides and outer sleeves too, I think. They also have strips, bars and sheet metal for ring and key making. I haven’t ordered anything from them yet but seems like a good company. Small quantities shouldn’t be a problem.
You first should check what tube sizes you need. You don’t want to remove too much material from the headjoint to make the new tubes fitting. On modern flutes, most makers use 20x0.5mm tubes (or nearest matching imperial sizes) for head liners and 21x0.5 or 22x1.0 tubing for the female slide. I’m using 22x1 nickel silver tube for the female slide and 20x0.5mm brass tube for head linings and if those sizes fit your Clementi, I’ll be happy to send you some for postage and maybe a beer. 
I checked the metalsmith.co.uk prices for nickel silver tubing and thing they’re quite expensive. But there are so few companies stocking that stuff, that’s where the prices come from…in Germany I have to custom order nickel silver tubing (companies to check are Eugen Geyer GmbH and Hermann Buntmetall GmbH). Rather expensive but you get exactly what you want…and Herrmann stocks basically every brass tubing size you could ever want for about 8-10€/meter.
The female slide sleeves are ususally hammered from silver sheet and soldered. It is a fun task to do (as silverwork generally is), but the current silver prices are spoiling the fun a bit. Anyway, that way you can make an exact fitting tube. That method is not really suitable for slides though, there are some pipemakers who mastered the art of tube rolling to a very high degree, producing telescoping tubes, but that’s mainly done for the eye as the slight imperfections on the outside catch the light very nicely. On our flutes the tube sticks in the wood, and there’s no light to catch (normally)!
Hope that helps somehow!
Yellowwhistler, thanks for the pointer! I just checked out the website and they have a lot, and in small quantities too. That’s a good resource to know about.
Steffen, thank you for the very generous offer! I will likely take you up on that, and would be more than happy to pay for postage, a beer, and something for the tubing! I’m actually on the road, traveling for the next week and a bit, but once I get back home I’ll do some careful measuring and make sure those dimensions will fit.
– Jon