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I Forge Iron

Problems welding Mild steel in gasser?

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Ok, here goes..My gasser welds high carbon steel fine. At around 12-14 psi. I have welded plenty of mild in coal forges so Im not competely new at this,LOL..
Now this what I tried in the gasser..
Prepar the mild, grinding smooth, bright and shiney. Flux, heat,tap,tap,tap..re-flux etc,etc..Same thing I do in a coal forge..
Now, Im thinking one of two things..This particular steel Im guessing is A-36, not 1018 because I picked it as a second thought at TSC not my usual place. Ive heard a36 is notorius for being funny to weld at times.
Second, Im not entirely sure my gasser is getting hot enough to weld mild??? I had it 5-6 psi higher than I use for welding higher carbon stuff..Inside "looks" hot enough, but Im not convinced??
At first glance it looks like a good weld. you can grind the weld line away..At the first sign of serious pressure it seperates :angry: You know how aggrevating that is, espically when Im use to welding without a second thought. Im feeling like a greenhorn here :blink:
Ok guys give it to me straight, what am I doing wrong or what is wrong in your opinions? Thanks A now very,very hunble blacksmith :P:P :P

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The more I think about the more I believe it was just not getting hot enough :mellow: It sounds strange that the forge will weld HC at 13-15 psi but wont weld mild at 20 psi but Ive got 10 psi more to go. I guess Ill try and crank up the juice..

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Mild has a higher melting temp than HC so heat may be part of the problem. Rather than cranking the primary psi (gas pressure) up and possibly introducing more oxy than can be burnt try reducing the internal volume of your forge with a piece of light fire brick or two. Another trick, if it burning too lean is to toss a piece of charcoal in, lump not briquette to consume any residual oxy.

My gasser welds for me with zero trouble. I can vary the interior volume easily though, I designed it that way. It's a refractory table with the lid on a jack, the sidewalls are light firebrick and can be moved around to configure the size and shape as necessary. It has four 3/4" ejector type burners of my "T" design on individual valves, each servicing 350 cu/in. And yes, it'll make all 1,400 cu/in welding hot though I don't need that much steel hot I did give it a try to see.

Another thing you might try is turning the piece over now and then and letting it soak longer. A36 can be kind of weird but I've had no trouble welding it. Oh yeah, my flux is 4 pts borax to 1 pt boric acid and it's a nice aggressive flux, works nicely.

Frosty the Lucky

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