TromboneChat

Hi all! I have a late '70s 4BF which is new to me, and it has the old-style King mouthpiece receiver that I remember reading about which is very slightly too big for modern large shank mouthpieces. I don't have pictures since the horn is currently in with Ron Partch for some TLC, but a Bach 5GS that I had lying around went in maybe half a centimetre past the usual insertion mark. I'm concerned that my Warburton, which usually fits quite low in normal receivers, will just sink right in - what have people done to fix this in the past? Are there options other than the somewhat expensive conversion to removable leadpipes?

A wrap or two of Teflon tape (plumbing supply) does wonders.

You can also remove the leadpipe and use press-fit pipes with the correct taper. Then you can have any old pipe you want as long as it is the right bore size.

BGuttman wrote: Fri Feb 22, 2019 9:45 pm A wrap or two of Teflon tape (plumbing supply) does wonders.

Would the Teflon tape change the instrument's sound/resonance at all?

Doug Elliott sells a shank that is specifically designed for that leadpipe. As others mentioned, you can also use teflon; some players actually have their mouthpieces turned down so they can use teflon to get the gap just right on any given week so I wouldn't worry about performance nearly as much as the hassle that you have to go through to do that.

Another possible option is to get a sleeve that fits your mouthpiece. The whole process isn't particularly cheap either though.

Maybe it's not the best way to proceed, but I made a homemade modification that works. In the end it is a geometry problem, so I realized that so that the mouthpiece does not go farther into the receiver, you have to increase the diameter of the shank 0.4mm. So if you are skilled with calculations, you just have to buy a 0.2mm thick copper sheet, cut it into a circular trapeze, mold it with the shape of the mouthpiece’s shank and insert it into the receiver. By inserting an old mouthpiece a couple of times, you will already have the perfect shape. For me, it works; better playing position and more focused sound without sacrificing the transmission of vibrations to the instrument.

The copper sheet Idea, gave me an idea I just used one wrap of thin aluminum tape on the mouthpiece shank... makes the mouthpiece set at the perfect place... the only potential problem is if the aluminum comes off in a chunk and messes up the slide... so far the aluminum seems like it will wear only if im stupid and turn the mouthpiece around in the receiver...

Matt K wrote: Fri Feb 22, 2019 10:28 pm Doug Elliott sells a shank that is specifically designed for that leadpipe. As others mentioned, you can also use teflon; some players actually have their mouthpieces turned down so they can use teflon to get the gap just right on any given week so I wouldn't worry about performance nearly as much as the hassle that you have to go through to do that.

Another possible option is to get a sleeve that fits your mouthpiece. The whole process isn't particularly cheap either though.

Sam Burtis had his mouthpiece shanks all turned down, then used Teflon tape to build them up to where they hit the “sweet spot” when inserted.

Doug's King shank really makes a difference in my opinion.!
King receiver is larger but the leadpipe has tighter venturi than most other largebore leadpipes. Maybe the less insertion depth acquired by Doug's King shank makes the air flow to have less turbulence..?
By the way, my real curiosity is,
Does anyone have positive experience with leadpipe swap, especially on King largebore or bass trombones??(4B, 5B, 6B)
I see many are doing leadpipe swaps with 2B or 3B, and many reports positive results, but for 4B or larger bones, there is so much less information regarding leadpipe swap.
My concern is if I swap my 4B leadpipe, then maybe the characteristic 4B sound would be lost, and nowadays it's not easy to get a old stock 4B pipes..

There is a trash benge 165f on ebay right now for $ 450 maybe you could experiment with a different slide that's basically the same and modify it's pipe