Hmmm ... I posted this a few days ago and got no responses. Surely someone has experience welding on wrought iron? Repost is below:
A friend of mine who does furniture repair asked me if I could help him with an antique chest, about 150 years old. It had metal strapping around it, apparently original to the piece, some of which had broken. Given the age of the piece, I told him the strapping was almost certainly iron, and I didn't know if I could weld it with my stick welder and mild steel electrodes. He tried a spark test on one of the broken off pieces, and said it seemed to spark like steel. I didn't see the sparks ... but I still find it nearly impossible to believe that a 150 year old chest was strapped with steel ... and it just looked like wrought iron to me ... but I gave it a try. And it welded with no problems at all, other than having to be really careful because the strapping was rather thin (less than 1/16" -- oh how I wish I had a TIG machine!!!).
So here's the question: How would *wrought* iron weld (not cast iron, not wrought steel)? Would it appear to weld pretty much just like steel? As I've thought about it further, I realized that I was wary of trying to weld it because I was thinking about cast iron, not wrought iron -- but those are, of course, completely different animals. And why would it look like steel in a spark test (assuming that my friend didn't mistake what he was seeing)? Given that the strapping was presumably fashioned in a coal forge, would it have absorbed enough carbon in the forge to make it spark a little like steel?
Of course, for the sake of authenticity, it would have been far better if I could have forge-welded the strapping back together ... but I haven't gotten that far in my metal working skills. Nonetheless, my friend was pleased with the results, and he reported that his client was even more pleased