TubeNet

The 3rd valve upper tuning slide on my Conn 3J has a crack in one side from the end, extending about 4" long. That slide is normally completely in so the end of the crack is not near the end of the outer tube, so it works normally.

I would like to be able do some slide pulls while playing so it should be replaced.

I measured the OD from 0.696" to 0.699". The ID 0.650.

A bit of searching does not find any off the shelf tubing this size.

Are there any sources for this tubing?

Will I need to custom make this tubing?

Readily available from Allied Supply - Conn .656 (ID of inner slide) tubing (maybe someone with access to their catalog will chime in with the part number).

You need to replace the outer tube, correct (the measurements you posted correspond with the inner slide).

Not to complicate matters, but you should know that I have seen slight variations in the size of tubing used, vis-a-vis 5J and 4J (and therefore 3J, too).

bloke wrote:Conn-Selmer's inside/outside 5J B-flat tubing should work...(no?)

If you have a repair shop or Conn-Selmer affiliate/dealer store with which you're on good terms, they can order it.

Of course (slaps forehead vigorously)

Are you saying the outer tube needs to be replaced along with the inner (cracked) tube?

bloke wrote: I believe (??) I recently fond out that the exclusive-Conn-made tubing is .658" bore, whereas the old Old/Reynolds/Conn/(Bach) tubing was .656" bore.

roweenie wrote:Not to complicate matters, but you should know that I have seen slight variations in the size of tubing used, vis-a-vis 5J and 4J

Yes, to all counts.

The complication is for the OP - he will need to be sure which horn he has before he orders his tubing.

IIRC,

3J, 5J = .656 (Conn)
4J, 4J = .658 (Olds/Bach)

I'll have to take some measurements, but I had both a 4J and a 5J (and a 12J, too) in pieces on my bench (at the same time), and one was a hair bigger than the other (I learned the hard way, in that I was salvaging the tubing from both horns to build another, and that they were not interchangeable).

My recollection may be off as to which was which

I had the same experience with a pair of old Kings. Same models, but different serial numbers and slightly different valve tubing dimensions.

Thank you all for the input.

If I proceed with this, the existing tubing will be very carefully measured before purchasing replacement tubing.

Additional input welcomed.

Many local music stores that service school music programs have an extensive morgue of old horns and parts. For example, I have gotten slide rings, leadpipes, etc., from my local tech for instruments that needed service over the years (of course, I have given him all my repair/replacement/modification business over the years, including putting the Besson bell on my Miraphone 186 - the Bessophone). Is the OP on good terms with such a local music store with a good band instrument repair department? Or, alternatively, is there anyone here on the forum who would "part" (pun intended) with such a slide from another otherwise wrecked tuba?