TubeNet

I intend to change a 5. rotary valve from right thumb to left fingers- as possible without lacquer burn marks by soldering.
Are there any experiences and know- how using modern adhesives technologies instead of soldering?
I ask to glue a new valve push button on a tube left side of my tuba.

Ulli

Some heat takes a soldered part loose. How would glued pieces be removed?

Even worse, if a future repair technician is not aware the part is glued instead of soldered, the technician might apply heat to the area and the glue could release vapors that are extremely harmful to the lungs and health of the repair technician.

Not a nice thing to do to the person who may be working on that horn in the future.

I don't know of any modern adhesives that have the same strength as solder. Any adhesives that might stand a chance would also tend to be brittle. Case in point... Yamaha has been using epoxy to attach their saxophone bottom bows for several years. Any 'smack' will tend to separate the bond.

A good hand can make a solder joint without damaging some modern epoxy lacquers.

I've never used "hot glue", but I believe it's a reversible bond - just heat it back up. I expect the bond isn't strong enough, but it's resilient, which might help. Might be good enough for prototyping the modification?

There are lots of good, strong epoxies out now. I have used epoxy on several of my tubas and have no hang-ups about it Probably not quite as "permanent" as good solder, but it's the next best thing, imo. The latest epoxy I've used was the clear Gorilla Glue epoxy. Looks best so far out of all epoxies I've used, and it's strong at 3300 PSI. Starts to set in 5+ minutes, but it takes hours for it to fully set/harden depending on temperature and humidity. Make sure you mix the hardener and resin together well and that the parts you want to work on are clean.

As far as removing old epoxy - no big deal.....just torch it and it will burn off. It stinks when you do it, but the fumes are probably no worse than the fumes from the lead-based solder. Make sure you have good ventilation. The lead-based solder actually scares me more - definitely don't wanna breathe that crap or have a molten lead-solder glob fall on my skin

Hot glue sticks are not very strong. They're great for holding corks on a mute, but I wouldn't use them on an instrument.

Epoxies on the other hand are in the same strength range of solder. I used JBWeld in an emergency to reattach a brace that is under considerable stress, and it has held for about 4 years of daily use. Solder would have been better because it's removable, but in this case if the brace comes off cleaning off the epoxy will be easy. It seems to me there are many applications where removal of the epoxy would be near impossible, while the solder can always be heated.

What is the composition of the solder usually used to solder components of modern brass instruments together? Does anyone use lead? Is it 95/5 tin/antimony? I know the 95/5 works well on copper and bronze.