Thread: Setting OXY-LPG Flame?

Hi All;
I’ve searched the internet, looking for instructions on how to set up my OXY-LPG flame for brazing. No luck, so I’m asking in the hopes that someone will help me.

I’m running my torch pressures (Oxy and LPG) at 5lbs and I’m using a 5N tip. I’m brazing mild steel, 1.6mm thick.

When I first light the LPG, it has a yellow colour with lots of black soot. Much like lighting acetylene. I turn down the flow until the yellow flame re-attaches itself to the tip.

At this point I turn on the Oxygen and adjust the flow to get rid of the yellow flame. I continue turning up the Oxygen and get a nice internal cone (light blue, almost looks white to me) inside the blue feathered flame. I’m looking for a neutral flame.

Where is that point – when it becomes a neutral flame? I can keep turning up the Oxygen and all that happens is that internal cone becomes smaller and smaller…

Secondly, the flame seems much too big for my liking. I’d describe the flame sound as "roaring". I can adjust the LPG–OXY flame sound from "roaring", through various sound levels of "hissing", all the way to silent. So, what sort of flow am I looking for?

Thanks

Norm