when to braze instead of silver solder?

[RipSlider]

hello.

Silver solder isn't the cheapest of things, although i have started to use the paste, which is both cheap and very practical.

however, my local B+Q now stocks 5 different types of brazing rods at very good prices.

I don't know much about brazing, so I was wondering if someone could give me some hints and tips on when to braze as opposed to Silver solder? Which metals? Which conditions etc etc?

Also, is brazing as sensitive to the use of the right flux for the specific brazing rod as it is in Silver soldering?

Many thanks

Steve

[bogstandard]

Steve,

I have just answered your other post telling you to braze the pipe rather than silver solder it.

With brazing, you need a much higher temperature. Usually you will use either oxy/propane or oxy/acet. You might get away with forced air and propane.

Bogs

[RipSlider]

Thanks for this.

Am I right in thinking that the powdered coatings on the outside of the rod act as the flux?

Are the variations for different metals?

Many thanks

Steve

[bogstandard]

That is a thing I can't answer Steve.

We never had flux coatings when I was 'into' brazing and bronze welding. We used to use a system the same as silver solder. Seperate flux and filler rod.

If they come pre packed, there should be some info on the packaging as to the use of the different colours.
I would think it is temperature range rather than material designation. But on the other hand, with silver solder you can purchase the flux for material types. I now use Tenacity 5, which is designed for stainless steel, but works well on everything else.

I do have a small quantity of very high temp silver solder, that was used for soldering up the pipes on the wagons that have banks of high pressure cylinders on the back. I have never been able to melt it, even with a large propane burner. So very high temp silver solder must be available, and if you coupled that with Tenacity 5 flux, then I think you would be onto a winner.

Bogs

[jwsvandr]

Thanks for this.

Am I right in thinking that the powdered coatings on the outside of the rod act as the flux?

Are the variations for different metals?

Many thanks

Steve

You are right the coating is flux. Haven't done much brazing but it is a good way to join dissimilar metals.

[tinkerer]

Silfos is a good way to join copper without flux. You can join brass and bronz with it using flux. I would braze steel.