I'm sure this is a stupid question, but I'll ask it anyway: I grabbed a random piece out of my scrap pile last night (round tubing, roughly 4 inch diameter) and started working on it, but it gave off a very strange colour and incredibly vibrant blue flames. It gave off a white discharge when struck. It was rusty on the outside, with some paint remnants, but not very much. It definitely didn't look galvanized, at least on first glance. I shut it down pretty quickly, wasn't worth gambling on until I had a better idea of what I was dealing with, and I was wearing a respirator, which I usually use out of paranoia for the coal smoke. Any thoughts as to what I was likely dealing with?

Lead burns blue..........no bueno

I'd guess that galvanization was more likely. Old galvanized items often have a few spots left over when rusty even sometimes covered by adjacent rust.

Either way bad to breath! (as is burning old paint!)

I too would think galvanised steel would be the problem, it may have been removed from the outside but tube has two sides, inside and outside.

Just this weekend I was attending an event and a student was working on a piece in the fire and I noticed the blue flame and told her to pull it out from the fire NOW, Startled her somewhat as I was only a spectator, however she removed it from the fire and you could see the metals colour. apparently it had just been picked up part forged to 'play' with.

On considered opinion it was determined the piece should have been scrapped and probably had been (Danger when recycling from a scrap bin)

The students had been warned about the perils of zinc, but had not associated this with the piece being worked, neither were they experienced enough to recognise the subtle differences in the flames of the fire.

No harm done this time, but an opportune warning for all.

Yup, I was pretty sure it was wrong and almost certainly dangerous, I was curious as to what it was. It was magnetic, which would seemingly rule out lead, so I'm going to assume it was galvanized, as has been suggested.

Not seeing it in person it is hard to say for sure. But I think greenish for zinc being burned off, and I think if there is powdery residue left from burning zinc it is yellowish. If memory serves lead burns with a blue flame (and different people may see colors differently) and there is a lead oxide that is white. It is still possible the bits of paint that were on it were lead based. There are some steel alloys that have lead in them, but I don't know if those would create a blue flame or not.

Of course the safest course of action (aside from always using known steel) is to shut down as soon as you think there is a problem.

ron

I commend you on being safety concious by shutting down the operation. Better safe than dead!
You say that you wear a respirator while forging. Always? Air fed or cartridge? Just curious.

Mark <º)))><

http://en.wikipedia.org/wiki/Flame_test

A partial list. I agree it is safest to put the material aside and clean the fire when flame colors are noticed. Blue is also Arsenic, which is more dangerous than zinc.

Phil

You say that you wear a respirator while forging. Always? Air fed or cartridge? Just curious.

When I'm not demonstrating, yes, I always start with one on, anyway. I usually use a cartridge respirator, but occasionally I just use a cloth dust mask. Depending on how it is and how hard I'm working, I will occasionally shed it after a couple of hours just so I can breathe normally again. I suppose wearing one is a little paranoid given that its just a hobby, but I figure that lungs and eyes are a lot harder to replace than skin.

When I'm not demonstrating, yes, I always start with one on, anyway. I usually use a cartridge respirator, but occasionally I just use a cloth dust mask. Depending on how it is and how hard I'm working, I will occasionally shed it after a couple of hours just so I can breathe normally again. I suppose wearing one is a little paranoid given that its just a hobby, but I figure that lungs and eyes are a lot harder to replace than skin.

i once used a dust mask while forging and it spontaniously combusted when i took a close look at a peice of orange steel, flames on the face are no fun