On Sun, 25 Oct 2015, David VanHorn wrote:

> I need some help sourcing the metal fitting in the picture:
> http://ecx.images-amazon.com/images/I/310e-2lm8RL._SY355_.jpg
>
> It's 7/16 OD, thin wall brass.  It matches K+S stock tubing except that t=
he
> end is rounded off and closed.
> http://www.hobbylinc.com/htm/k+s/k+s8137.htm
>
> The diameter is critical, the fitting it goes in doesn't flex much.
>
> I am not too picky on length, more than half is good, more than an inch i=
s
> a problem.
>
> A hole in the closed end is actually good, but not critical.
>
> Why:
>
> I have an antique "Violet Ray" device that I would like to make some ends
> for.  It's a rare one, which runs from 32V "farm current".  Such devices
> were made by the truckload around the turn of the century, to cure whatev=
er
> ailed you, but the vast majority are 110 or 220V for europe.  The farm
> current device is unique.
>
> I could just go buy something like in the pic, but I want to make somethi=
ng
> more like a geissler tube, which is a bit of a project.  To that end, I'v=
e
> taken up glassblowing, found a source of uranium glass, built a vacuum
> manifold and "filling station" and learned to seal off these tubes when
> under vacuum of 1-10 torr.

If you've gone to the trouble of taking up glassblowing why not take the=20
final (tiny) step and make your own ends? You say the "k+s8137" matches=20
except for the closed end. Simply get some brass sheet and hard solder it=20
to the end or the brass tube with a small gas torch. This is not the usual=
=20
low melting point solder used in electronics. Look up hard soldering=20
(melts at about 600+ deg C). This will give you a square end that you can=20
easily round off using a buffing wheel. Depending on the radius of the=20
curve that you want, just increase the thickness of the brass plate (or=20
build up thickness using multiple plates). I've used this technique to=20
make rounded end caps out of sterling silver sheet (no pre-made tube just=20
rolled up sheet) so I can safely say that it does produce good rounded=20
ends.

Regards
Sergio Masci
--=20
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