Solder / brazing torches

[Myles]

At the moment I use MAPP hand held torches, Bernzomatic ones. I just checked the specs and my main torch is about 3 kW, the other one is a fine pencil torch so it will be a lot less.

I know some folks use oxy acetylene and although the flame is hotter, sometimes you just want MORE heat not necessarily hotter heat.

I am limited by my equipment. Soldering is fine but brazing is a bit more troublesome. I can braze short bits of 54 mm tube but my torch just does not deliver enough volume of heat to work on bigger items without a secondary heat source. If I can get the work piece hot then the MAPP torch can top up the joint to brazing temperature, but a longer length of big copper tube really soaks up heat.

I am thinking of an upgrade to a Sievert propane torch, as these are available up to 86 kW. I am thinking of a more moderate 10 kW cyclone burner.

Have any of you used one of these propane torches? Perhaps in your normal line of work? Any recommendations?

[Phantom]

This is the sort of thing that's causing me to be a bit of a drag arse Myles.

I've only got a basic plumbing type blow torch myself. I've got contacts who use full oxy/DA so I'll ask them to flash it all once I've eventually got my finger out and got it all dry assembled.

I was reading on one of the HB forums the other week, about one of the members having to join copper and stainless. He said about having snags with the flux, when using a MAPP torch, but it seems to have worked well enough to hold low(ish) pressure (it was some sort of repair to his kegging kit) once the cleaned, waiting to be soldered/brazed surfaces had been cleaned in hydrochloric acid.

How easy it would be to get I don't know, the bloke is a chemist so probably sorts that himself or through his work......

[Myles]

You can do 54mm stainless to copper with MAP gas and high silver content solder with borax flux. With stainless ferrules to copper tube you really want the copper inside the stainless because of the expansion coeficients. You can do it the other way, but there is a bit of an issue with compatible diameters.

Soldering copper to thin stainless pots etc is also possible but I have really gone off it. It is just so easy to overheat the stainless and that really messes it up further down the line.

These days I try not to solder stainless at all if I can possibly avoid it. i am thinking about a bigger torch so I can do bigger copper to copper items.

[Phantom]

Was thinking of looking into how much the replacement oxygen cans are for the hobby sized MAPP/O2 sets. That way I should be able to braze or solder just about anything I'm likely to need to do.......

Without the expense of bottle contracts etc......

[scarecrow]

The yellow Bernzomatic gas cans are propylene gas, not Mapp gas. They stopped making Mapp gas about 5 years ago due to expense etc etc. Bernzomatic call the yellow cylinders Map Pro. And cunningly left the containers yellow. Mapp gas is actually methyl acetylene, with a flame temp of about 3000C. Map pro is only 2000C.

But.....

I have a Bernzomatic TS8000 and use 5% silver rods (yellow tip) to hard solder 4" copper. Works a treat.

Worst part about it is ..... you only get one shot at it because it don't wanna come apart after that, no matter how much heat you give it.

I also use 8% silver solder for any SS work. I think it's called staybrite 8. CIG 965 acid flux is the ants pants for this.

scarecrow