Brazing

[Vexis]

Is it possible with aMig?
Whats the ins and outs if so?
Brass copper or steel .
Ive seen a roll of brazing wire available but was intrigued as to what or hows it done .
A gas torch is my only experience with brazing

 

[optima21]

I think you might have issues with brazing brass, as I tried to TIG braze some brass parts and had issues with the zinc in the brass boiling off. I end up making a couple of new parts and silver soldering them together.

 

[GrahamGKD]

There is a bit on it here and here. From what I remember the wire is pretty expensive!

 

[rtbcomp]

I think you might have issues with brazing brass, as I tried to TIG braze some brass parts and had issues with the zinc in the brass boiling off. I end up making a couple of new parts and silver soldering them together.

You probably got the brass too hot - brazing rods are basically brass.

 

[optima21]

^^^^^ yup,sounds about right, and you don't see the colour change when the metal heats up, and they were only small peices that I was trying to braze together

 

[dan.taylor.1]

I thought brazing rods were silicon/aluminium bronze not brass?

 

[Wendelspanswick]

I thought brazing rods were silicon/aluminium bronze not brass?

That threw me too and then I reread it and realised the item he was brazing (brass) was giving off the zinc!

 

[dan.taylor.1]

Getting it too hot then. I've brazed brass with no issues until it gets too hot, then you get zinc coming out (looks a bit like welding galv that you've not cleaned properly iirc)

 

[rtbcomp]

I thought brazing rods were silicon/aluminium bronze not brass?

From Wikipedia

• Aluminum-silicon
• Copper
• Copper-silver
• Copper-zinc (brass)
• Gold-silver
• Nickel alloy
• Silver[1][6]
• Amorphous brazing foil using nickel, iron, copper, silicon, boron, phosphorus, etc.

so we're both right!

 

[dan.taylor.1]

Is it still brazing if you're using brass, is that not technically welding? you may not be melting the parent metal but the weld metal as ischemic is the same, where a brazed joint is just a secondary metal melted into the miniscule nooks and crannies of the joint.

 

[rtbcomp]

No, welding is melting the parent metal (or other material such as plastic).

Brass brazing rods will have a lower MP than the parent metal.

 

[norlander]

re the mig brazing, iirc, there is kit to do it but its a bit special I think, when I was an apprentice, (only last month) I think brazing was also called hard soldering (not to be confused with silver soldering) but where I was, it was called brazing.
I think the MIG brazing kit is or was for stuff like Reynolds tubing, but you need Tech Al or Hotrodder to confirm that, I really can't remember that far back (even if it was only last month)

 

[Dee J]

I get confused with the terminology... but there seems to be 1) The sort of brazing done in a brazing hearth, where the parent metal is heated overall and the braze is drawn into the join by capillary action. And 2) Locally heating the join area by oxy, tig or mig and building up a fillet of braze - this second method (confusingly) also seems to get called braze welding or bronze welding (even though the parent metal is dissimilar to the braze, and not melted in the process). Have I got that right.