Metal that will not arc

[VirginiaAgent]

So, a recent wind storm caused a metal rod type bird feeder holder to bend badly at the base. It's the kind that you buy at tractor supply, kind of a black metal, that I assumed was iron. I cut out the bend, cleaned the metal, and proceeded to weld it back together with my Stickweld 250. I could not get it to arc. I repositioned my negative clamp, changed rods, changed the welder's settings, everything I could think of. Nothing.

I was afraid something was wrong with my welder, so I grabbed a piece of scrap iron, and it arced immediately.

Are there types of metal that will not allow an arc?

I'm an amateur, so there may be a simple answer that I'm just missing.

 

[CNC Dan]

Did you grind the black stuff off?
Does a magnet stick to it?
Could it be anodized aluminum?

 

[k0ua]

Any kind of metal would draw an arc, even aluminum. Not saying it would weld, but it would arc.. the only reason for not drawing an arc, is because you had no continuity between your "ground clamp" and the rod and/or stinger. If the piece of metal has a piece of wood, or plastic in the middle of it between where the ground clamp was and where you tried to strike the arc, it wont arc, if it is made from several pieces of metal that was painted well in the joints it wont arc.. but if it has continuity it will arc. Get you Ohmmeter out and measure the resistance from where the ground clamp was to where you were trying to start your arc, and it will tell the tale.

James K0UA

 

[CNC Dan]

Any kind of metal would draw an arc, even aluminum. Not saying it would weld, but it would arc.. the only reason for not drawing an arc, is because you had no continuity

James K0UA

Anodizing puts on a layer that is non conductive. Some layers are thicker than others, and very hard.

 

[Mark @ Everlast]

That would be plastic? lol. Just kidding. Hope you figure it out. Let us know.

 

[k0ua]

Anodizing puts on a layer that is non conductive. Some layers are thicker than others, and very hard.

OK, or even a plastic coating of some kind or even a really good paint job of course. Anything that prevents electrical continuity. I nearly always have a wire wheel in one of my 4 1/2 inch angle grinders, and clean the path of the joint I am going to weld, Can't ever hurt, and often helps a bunch.

James K0UA

 

[joshuabardwell]

OK, or even a plastic coating of some kind or even a really good paint job of course. Anything that prevents electrical continuity. I nearly always have a wire wheel in one of my 4 1/2 inch angle grinders, and clean the path of the joint I am going to weld, Can't ever hurt, and often helps a bunch.

James K0UA

Always grind clean the joint! And if you can, grind the ground clamp location too!

 

[Redneck in training]

That would be plastic? lol. Just kidding. Hope you figure it out. Let us know.

If it is plastic or wood you have to use rod made of the same material. In example to weld oak you have to use oak rod.

 

[k0ua]

If it is plastic or wood you have to use rod made of the same material. In example to weld oak you have to use oak rod.

Yes, but we are talking about Oak filler rod here, as you must use an oxy-fuel process to weld Oak, not any of the electrical processes. Right?

 

[Shield Arc]

That reminds me of one time installing conveyors in a UPS facility. Two of us were welding side pans on this long run of conveyor. The side pans were painted green, and we were using 6010 running down hill to weld the sheet metal to the angle iron braces. The boss came by and started complaining about us burning up the paint, and how much more labor it was going to be to wire brush and repaint. My partner being somewhat of a smart a s s says, "well if you would have bought the right rod this wouldn't happen"! The boss asks what rod should he get. Partner says "well green rod of course"! Boss takes off to the welding supply to purchase green welding rod. Lets say he wasn't very happy when he came back.:laughing: