Joining metal components

[Garrett44]

I’m looking for advice in joining small metal components, similar to the nut and bolt sculptures you see online (https://www.google.com/search?q=sculptures with nuts and bolts&ie=utf-8&oe=utf-8&client=firefox-b-m), but I’m using some slightly larger components e.g. hinges, brackets etc. The components are steel (not stainless), aluminium and brass. Some are old and corroded, others are brand new.

Cost is starting to be an issue as I’ve had a number of failed tries. So far I’m limited to using a soldering iron and a butane blow torch, what I had available and what was low cost, have tried soldering (does not adhere), tried brazing (cannot get a high enough temperature. Not sure if I should try silver solder, this is what tutorials for nut and bolt sculptures advise but given soldering had zero success I’m doubting this.

What will work? What is suitable? Do I need to go to welding? Is there some welding solution that is reasonable cost, small scale and can be used indoors (no access to a workshop or outdoor space)?

 

[Phil Pascoe]

If you can't get it hot enough to braze, you can't get it hot enough to silver solder.

 

[ChaiLatte]

You might do some research on the materials you are using. Steel is iron-based. Brass is copper-based. Aluminium is aluminium-based.

There is only one method which will join all three together, and that is glue.

Soft soldering will join steel to brass. Silver soldering will join steel to brass. Brazing will join steel to brass. Welding will join steel to steel. You can buy specialised low temperature solder to join aluminium to aluminium (confusingly called lumiweld). Joining aluminium to steel or aluminium to brass is challenging.

Every joining method you use will work better if the item is clean. A flux will prevent the clean items oxidising in the atmosphere while they are heating up to the temperature of the filler material. Try to shortcut by joining dirty, rusty, corroded, tarnished items, with no flux, and you will cry.

Please read some of the items here:

https://archive.org/search?query=soldering+brazing

 

[ChaiLatte]

If you can't get it hot enough to braze, you can't get it hot enough to silver solder.

In this area of joining things together, we tend to be a bit fast and loose with the terminology.

You could have a low temperature brazing material that melts at a lower temperature than a high temperature silver solder.

By and large though, brazing is a hotter process than silver soldering (look up the temperature for Easyflo and Sif Bronze), so what you say is not necessarily correct - you could quite easily be too cool to braze but silver solder adequately.

Traditionally, 'braze' and 'brazing' are used to refer to copper-based materials (brass, bronze), but 'silver brazing' is also a term of art.