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Alternative to soldering?? Cold bonding???

Posted: Wed Aug 28, 2019 2:55 pm
by 2ba4t
Are Superpro copper glue - Just for Copper: any good for us??

Various cold copper bonding ‘glues’ seems to have been around for decades. If they are so good we should all have abandoned soldering. I can understand the natural conservatism of professionals and fear of leaks and consequences. Most reactions seem to be, ‘What was wrong with the old methods?’ ‘Would not touch it with a barge pole’ ‘Bound to leak eventually’. It may be no good for high pressure uses or refrigeration and specialised chemical applications – but tubas?
Torching around valves and on lacquer is a pain and the acrobatics of wiring up a series of joints in close proximity and getting them all to melt and bond simultaneously can be a nightmare. Just carefully cleaning and then glueing with this magic stuff seems very attractive. [These amateurs!!!! :oops: ]
Anyone tried this? Why do we not all use it? Any experience please?? [You can answer anonymously if it is unprofessional to admit using this stuff :mrgreen:]

Re: Alternative to soldering?? Cold bonding???

Posted: Wed Aug 28, 2019 3:11 pm
by roweenie
I've never heard of this method. How does one "undo" the bonds made this way? Heat, chemicals, or otherwise?

Actually, "soft" soldering (with flux and lead/tin solder) is not that difficult, once you get the hang of it.

Re: Alternative to soldering?? Cold bonding???

Posted: Thu Aug 29, 2019 9:20 am
by Big Toot
bloke wrote:If someone had an instrument with a leak in a slide joint in one little spot, didn’t want to burn the lacquer, didn’t want to mess up the silver or gold plating, and just wanted to stop the leak, I don’t see what the heck would be wrong with putting a drop of super glue down into the little leaking spot – particularly if there is a lime or some other contaminant in there that would make it a really involved solder joint to repair.
After all, what is most important: the method, or the results ?
Not that my opinion is worth the bytes that it's typed with, but I wouldn't see anything wrong with that, all things being equal.

Re: Alternative to soldering?? Cold bonding???

Posted: Thu Aug 29, 2019 12:04 pm
by 2ba4t
I think it is a great idea if it works permanently. I would hate to have the player end up with several bits of tuba. Anyone used this brand - Just for Copper?? It should revolutionise tech work http://justforcopper.co.uk/" target="_blank" target="_blank
The site is like Hamlet's mum - it claims too much - but if it is true ....
also see https://www.amazon.com/Copper-JFC050-Ou ... B000VHYRGA" target="_blank" target="_blank and https://www.doityourself.com/forum/plum ... -instead-s" target="_blank" target="_blank.

I think that on a lacquered bass or with lots of close bends and joints needing soldering simultaneously it should be a dream. It is easily undone by applying heat from a torch apparently - so with lacquer you get only one bite.

I'll experiment.

Re: Alternative to soldering?? Cold bonding???

Posted: Fri Aug 30, 2019 12:06 am
by The Big Ben
If it is a crack or hole and doesn't need to gain strength, what's wrong with a small piece of electrician's tape? No glue cleanup before soldering.

Re: Alternative to soldering?? Cold bonding???

Posted: Sun Feb 02, 2020 11:07 am
by 2ba4t
I have been busy moving continent etc. But I tried 'Just for Copper'. It can be excellent - especially on lacquered areas - if:
1. you prepare both surfaces with a 60 emery cloth and then white spirit - just to ensure they are clean.
2. you rotate the joint as you feed it together.
3. there is not too much play between the outer and inner pipes.
4. you use suitably thick shim if there is a gap. You need to emery cloth and clean all contacting faces. But you can glue the shim padding in the receiving pipe first by using e.g. a suitably sized piece of conical wood, let it dry and then proceed with the actual joining. Fiddly but possible.
3. you line them up carefully first - 'cos this stuff dries very quickly.
4. unseal it with gentle heat and then emery and clean again.
5. you have a good bank manager. But actually a very thin thread works great.
6 you are wary using it on large bore joints. I think it may not have the same mechanical strength as on narrow pipes - leverage, thickness of material, etc.

It is no good I found for simply gluing small surface areas together e.g. the arched support for the valve below is soldered on.
Photo0008resize.jpg
The valve is screwed to that arch.

It is brilliant for complex multi-jointed jobs in close proximity. None of the wiring up and fiddling, or trying to solder ten adjacent joints which keep popping apart as you apply the torch to another joint. Even those flexible-hose tiny torch nozzles did not help me much. This dependent fifth valve pictured above which I put in an alternative 4th valve slide does not look pretty but it works great and was a simple matter of gluing it together. It is as solid as soldered work and non-leak even with that ancient valve.
Photo0007resize.jpg
Resizesm.jpg
Should look OK when polished and lacquered.

Hopes this help someone somewhere.