Stuck (glued!?) Lexan shank in a sousaphone bit

[arpthark]

Howdy folks,

Well, I've got myself in a bit of a pickle. I bought on FB a red Kelly mouthpiece that was advertised as coming "with brass fitting" which was a sousaphone bit. I needed a bit for my helicon so I figured, why not for $25 and I could hang on to a spare Kelly instead of buying a brand new bit.

Well, that Kelly was S-T-U-C-K. Mouthpiece puller would not work. Penetrating oil would not work. Very careful application of a vise and visegrips and all matter of things wouldn't work. Gentle heat did not work. I eventually goofed and SNAPPED the mouthpiece bowl clear off the shank in the mouthpiece. It's gotta be superglued on or something. So now I am stuck with a sousaphone bit with a stuck, broken Lexan shank in it.

I have tried gouging with a triangle scraper, hammering from the opposite side, etc. etc. and it will NOT come out. I even tried going in with a Dremel in hopes that it would crack the Lexan but it just gouged it. I'm thinking I might have softened it up and now it is really glued (if it wasn't before!) to the inside of the sousaphone bit.

Should I take the torch to it gung-ho? Can Lexan dissolve? I am thinking that it is such a rare issue for Lexan to break that this is an uncommon problem, especially in the curved sousaphone bit which makes extraction difficult. I just want a bit for my 100 year old helicon!

Any ideas? Thanks!

[bloke]

sorry about that !

Mouthpiece-wise, I experimented with lexan screw shanks into both stainless steel threaded cups as well as lexan threaded shanks into lexan threaded cups...They would seize. (' too much expansion/contraction.)

I suppose we could have cut more "slop" into the threading, but the point is to have a viable mouthpiece, and not just "something that comes apart easily" (as BOTH should be possible, rather than choosing between the two)...so this idea was abandoned.

With the Lexan rims (though very messy to fabricate, and which gum up the machine) their diameter is large enough to offer enough grip/torque to free them from the cups.

You can try rawhide mallet tapping (on the outside of the tuning bit), but imagine a nerf ball jammed into a sousaphone "way down in there". If you sent a 5/8" diameter steel ball all the way up in there (feed in from the main slide opening), do you think you would have any success beating that wedged nerf ball out of the body of that sousaphone with that 5/8" diameter steel ball?...I'd wager against it.

[arpthark]

Thanks Joe.

I was trying to expand the brass to remove the Lexan, so I put it under very hot, near-boiling water.

I think this made the Lexan soft enough that it basically turned into molten hard candy inside the sousaphone bit. Soon thereafter is when the shank snapped.

I'm thinking about just taking the torch to it.

Are sousaphone bits typically soft-soldered or silver-soldered together?

[bloke]

Thanks Joe.

I was trying to expand the brass to remove the Lexan, so I put it under very hot, near-boiling water.

I think this made the Lexan soft enough that it basically turned into molten hard candy inside the sousaphone bit. Soon thereafter is when the shank snapped.

I'm thinking about just taking the torch to it.

Are sousaphone bits typically soft-soldered or silver-soldered together?

Sousaphone bits are lead soldered.
You might try running a large screw into the broken off shank of that mouthpiece (if you - somehow - can manage that...??), putting the screw into a vice, really cranking on the vice, putting on some BAG (big-ass gloves) and try (??) rotating the bit so-as to not unscrew the screw.

Lexan melts at c. 300 degrees F., and lead solder melts at only 50 or 60 degrees (I'd have to look it up) more, so you wouldn't have enough of a leeway, and - even if you got lucky - you would end up with a mess inside that tuning bit.

Another option (probably the first thing I would try, if nothing else worked) would be to quickly un-solder the tuning bit (so as to not melt the lexan very much at all), BEAT the broken off mouthpiece shank out from the small end, and then solder the tuning bit back together.

[arpthark]

Another option (probably the first thing I would try, if nothing else worked) would be to quickly un-solder the tuning bit (so as to not melt the lexan very much at all), BEAT the broken off mouthpiece shank out from the small end, and then solder the tuning bit back together.

This might be what I will try. There is not enough exposed shank that any is sticking out -- hence the gouging and scraping I have been doing (my poor bit!). Unfortunately it snapped off about a quarter inch inside the bit in an asymmetric shape.

I will post a pic to show what I am dealing with, but I think that I will just try unsoldering it and trying to remove the gunk inside.

I had been trying to preserve the lacquer on the bit, but we will see how that shakes out.

[bloke]

I suspect (even though the picture shows two) this is ONE for $26 (postage incl).

$26 is prolly ok...

https://www.ebay.com/itm/195283269346

Mess around with your...uh...mess, later.