odd little idea?

First, I'm a nonwelder. Isn't the idea behind an inert shielding gas, to prevent oxidation caused by oxygen. Isn't the O in OA the problem? Or is all the oxygen bound up in a proper flame?

Mikek

Greetings Bill, I'm pretty sure the cumbustion products act as shielding when gas welding. I know, for example, that when the flame is adjusted a little "soft", so that there is excess carbon present from the cumbustion process, the carbon will suck up oxygen in the immediate area and this is helpful when brazing becuase it reduces the oxidation of the metals being brazed and the brazing slloy itself. Why not make an orofice that consists of a ring that surrounds the torch tip and has a multitude of holes that would flow argon gas around the flame? Report back please with your results. Cheers, Eric

Well :-) that is how an under water torch works. But of course, under water the shielding gas is air :-)

Can see logic you are seeking - but flame naturally does the right thing anyway. One reason OA works so well. A "neutral" flame is neutral only to the reactions in the blue cone. That leaves gases still with further to burn. So they "get" any oxygen trying to come near the molten zone. The gases from the first-stage ("blue cone") reaction flow outwards - completing combustion for more heat and no oxygen (nor nitrogen, etc) can come in. There is a pressure-welding system for rails where so long as you keep the flame running without stop from starting up from cold between two planar end-faces, you can eventually push the rail-ends together and they will bond. Heat and cleaness - you get a rapid "diffusion bond"

- aided by a small amount of "upset" and plastic deformation.

Essentially your good idea is redundant by reason that you already get the correct shielding effect anyway from the inherent nature of the oxy-acet flame.

Rich.