TromboneChat

I have a Conn 6H with a press in leadpipe and I remember wrapping it with teflon tape to keep it from coming out too often. Well its been years since I've touched it and I'm finding it very difficult to remove so I can try it with another horn. Is there a trick to removing it with out damage or should I just bring it into the shop?

Thanks,
Mitch

What have you tried so far?

I tried gentle prying around the rim and slip joint pliers with padding but very gently to avoid damage.

It's not impossible that corrosion has fused it to the inner tube, but that depends how many years 'years' is, and how clean you've kept it.

Don't do anything without a mouthpiece in the receiver - it'll stop you from collapsing the pipe if you apply too much pressure to the collar. Cannon plug pliers or similar with Delrin lined jaws would be ideal. Water pump pliers will chew up brass very easily, though you can get away with using those if you wrap the part with something firm but flexible like an appropriate thickness of leather. You don't want to crush anything, but you also need to grip firmly enough to avoid slipping, so don't be tooo gentle. Small movements to release and walk it out, not one big twist.

If in doubt, off to the shop.

Good tip about inserting a mouthpiece into the receiver. How about some heat or penetrating oil? It would have to be pretty low heat to avoid damaging the lacquer but it work great on my car.

Mitchwolberg5 wrote: ↑Tue May 30, 2023 4:42 pm Good tip about inserting a mouthpiece into the receiver. How about some heat or penetrating oil? It would have to be pretty low heat to avoid damaging the lacquer but it work great on my car.

Melted teflon tape won't be fun.

Oil's not going to do any harm, but if you think it might be corroded in place then plugging the inner tube and giving it a white vinegar soak is the obvious first step.

I'll give the vinegar soak a try and if that doesn't help its off to the shop.

1. White vinegar soak for sure............dissolves the oxidation.
2. Failing that, WD-40 has less surface tension, and may penetrate the interface better.
3. The leadpipe is most likely stuck along only the bottom third of its length. There's no lacquer there, so hot water
can be safely used at that spot to create a little expansion.

Make sure you don't insert a mouthpiece into a leadpipe that you heated. It will get stuck. Really bad.

I thought I'd mention that you really don't have to worry about melting the Teflon tape. Teflon melts at 350-400 C which is much higher than solder, which melts at 170 C (or so)

BGuttman wrote: ↑Wed May 31, 2023 4:15 am I thought I'd mention that you really don't have to worry about melting the Teflon tape. Teflon melts at 350-400 C which is much higher than solder, which melts at 170 C (or so)

It's not actually made of teflon. It's PTFE. Probably would melt.

brassmedic wrote: ↑Wed May 31, 2023 1:21 pm

BGuttman wrote: ↑Wed May 31, 2023 4:15 am I thought I'd mention that you really don't have to worry about melting the Teflon tape. Teflon melts at 350-400 C which is much higher than solder, which melts at 170 C (or so)

It's not actually made of teflon. It's PTFE. Probably would melt.

Well, actually Teflon™ is merely a trademarked brand name for various products made from/with polytetrafluoroethylene (PTFE). If the tape is really PTFE (popularly called Teflon, even when it is not the trademarked product) it shouldn't melt below temperatures of about 327°C (621°F). That's VERY hot!

Posaunus wrote: ↑Wed May 31, 2023 4:07 pm

brassmedic wrote: ↑Wed May 31, 2023 1:21 pm

It's not actually made of teflon. It's PTFE. Probably would melt.

Well, actually Teflon™ is merely a trademarked brand name for various products made from/with polytetrafluoroethylene (PTFE). If the tape is really PTFE (popularly called Teflon, even when it is not the trademarked product) it shouldn't melt below temperatures of about 327°C (621°F). That's VERY hot!

Oh, I see. So it is the same stuff that's on a non-stick pan?

Well, there are a bunch of non-stick treatments, but yes one of the original ones was PTFE.

The thread sealing tape with PTFE / "Teflon" may have a specific heat rating, depending on the formulation. There's more in it than just the PTFE in it I believe.

The stuff sold in hardware stores for plumbing use is generally pure extruded PTFE 1.5 mils thick. (about 35 microns.) There are other products with adhesives or substrates,but I doubt any of us are using any of them. In British Commonwealth countries the pipe tape is colored for different uses (yellow for natural gas, green for oxygen, etc.). Again, I doubt any of us are using anything other than the white.

I really wouldn't worry too much about melting the stuff.

Fair enough. Should have checked... I see 'plastic' and think No Flamethrower For You.

In this case, the OP isn't even trying to melt solder, so a bit of heat to encourage the penetrating oil clearly is nowhere near the PTFE melting point. If it comes to this, put the oil in from the stocking end - it's not the taped collar side that's going to be corroded in place.