Brazing with a big propane bottle and plumbers torch.

[Wedg1e]

So if brazing isn't welding... it must be soldering...

 

[nickjaxe]

Are the brass type rods that are more suitable for a propane torch brazing? ie low temp brass rods.

 

[Keithmac]

So if brazing isn't welding... it must be soldering...

I'd class it in same bracket as soldering (high temperature soldering!).

 

[Jack Ryan]

So if brazing isn't welding... it must be soldering...

Brazing is exactly the same process as soldering but at a higher temperature.

Braze welding is a different process but is still carried out at the brazing temperature which is lower than the base metal's melting temperature.

Jack

 

[nickjaxe]

Think I have given up on the idea of propane brazing.

Many years ago I had a carbon arc brazing torch.....seem to remember it worked ok in a fashion.
I'm sure its in the loft.....can see it not being very controllable working on small brass unions like I am working on.

 

[zeppelin builder]

What size of tip and psi of air do you recommend to start with?

i just use its original tip its like a fireball when lit then i just give it more air till the flame comes down
to a bright blue with the cones
converging

 

[zeppelin builder]

dont bother it will just blow out the second you try and light it . its difficult enough using propane and pure oxygen but well; doable

its not a single tip o/a torch it has mutiple holes like a superheater or pre heat torch and is for heating in a hearth the flane is about 20mm wide and 150 long
they ran on town gas and air
point the porch up out harms way when lighting as its a big fireball
and get the air on and trim the flame back asap

 

[BarrieJ]

It seems Flamefast still make a gas/air torch. Pretty sure both Bullfinch and Harris do too, although the Harris torch is the best part of £400.
If I recall, the torch I used in school had a brass body with two 'toggles'(?) one to control gas and one; air

(Taken from the Flamefast website)
Separate thimble wheels control both gas and air on the 3070 torch. A range of interchangeable nozzles are available.

The 3070 operates with 1VM, 2VM and 3VM nozzles giving flame lengths from 50mm to 600mm. A 240mm burner tube extension is also available.When used with a 2VM or 3VM nozzle, the burner tube is ideal for melting precious metal. For this operation the air pressure should be at least 15lb. per sq. in. For the largest output with a 3VM nozzle, air pressure should be up to 25psi.

Ideal for plumbers, foundry dieheaters, silversmiths, jewellers, car and motorcycle manufacturers, car radiator repairers and manufacturers. The 3070 is supplied with a 2VM nozzle as standard which gives a 30mm flame length.

https://www.flamefast.co.uk/3070-gas-torches.html

 

[Seadog]

If I recall, the torch I used in school had a brass body with two 'toggles'(?) one to control gas and one; air

You did. I'm damned if I can find an image on line, though. Fed from a small compressor and town gas.

 

[Onoff]

I bought a Rothenberger MAPP torch for the express purpose of melting the braze around the front wing / headlight bowls on Ford Capris. It didn't work and some butchering ensued! Still never quite figured the best way of getting them off, whether they were just spot welded or whether the braze I came across was done post factory.