Oxy-Gas WELDING
I am no "expert" on the subject but I was into a project a couple years ago where I was building 2 x 2 square tubing, after other parts were assembled onto one side of the tube.
I was using my Oxy-Accetline (?) gas, WITH NO FILLER MATERIAL, and welded the two pieces together simply by applying the proper heat, letting the material come up to the melting-point and forming a puddle and moving on down the joint/connection point, until the whole seam was finished.
Once I got the proper heat applied, it was simply a matter of watching the puddle of melted steel flow together from each side and moving on down the seam.
It made a real nice seam/weld and has stood up to some pretty rough useage since that time too.
I have used the Oxy-gas system to "weld" some thicker materials together too and they seem to "fuse" together, with or without a iron-wire filler, depending on the gap that was there to be filled.
I will agree with the guys who don't recommend BRASS ROD be used as a filler though. Brass is pretty brittle and it will break if it is put under pressure. A STEEL FILLER, like wire, be it thin or even #9 black wire, works good when "joining" two pieces of heavier steel together.
I was told by an "old-timer" that the Black Smiths of years back used their charcoal-pot and forced air to create enough heat to melt some of that old steel they had (back then) and those pieces look like they were cast units, when in all actuality - they were WELDED TOGETHER with just heat and the base material.
As far as I'm concerned, it is one of those "AQUIRED SKILLS" that one gets,
with a lot of PRACTICE............ But IT DOES WORK