A friend recently tore down a 1914 piano in his basement and passed the iron harp along. I sent a piece to be analyzed, probably XRF spectroscopy but I'm not certain. The thing that jumped out at me was the level of arsenic, though this could have been residual from the paint. I need to have a few other pianos analyzed to see if this is a trend or an anomaly. I may have to rethink my sourcing strategy and just use ingots, but I was really hoping this would be viable, both for skillets and for the flywheel. Thoughts?
May not be the paint. I've been doing some study regarding aluminum alloys for high temperature stability and arsenic is apparently not an uncommon alloying additive - for aluminum or steel. Same group as Antimony and Phosphorus. Arrrrsenic - A pirates favorite poison.
Arsenic was used to poison insects in the bad old days. The last thing you want in the piano, is moths eating the felt on the hammers.
Unless you take your tea with two lumps of piano iron, it probably matters not at all if there is arsenic in the iron. It is not likely bioavailable. Much like leaded steel, the poisoning risk is essentially zero though the worry risk seems high. Denis
You will need a lot of good luck in finding cast iron ingots because pig iron is rarely used now. The only pig iron I know of that is available is used for ductile iron production. I melted two those ingots to see how good it was for castings. I was told that it was not suitable for cast iron castings and the result was chilled iron even though I added ferrosilicon. Cast iron and ductile iron are two different metals. Another source is cast iron round bar for machining although it is a very expensive way to pour cast iron castings. I always suggest if you melting cast iron for the first time and want machine castings use cast iron sewing machines.
Hmm, I think both commercial foundries near me buy pig iron and then add inoculants as needed to bring it into spec for grey or ductile iron. I like using ductile returns from one of them to cast grey iron parts. One of them has a spectrometer and has developed a spread sheet to make it easy for their workers to make accurate adjustments. The other one uses a formula. The one that uses a formula can’t remelt grey or ductile and still be confident of hitting specs. The guy with the spectro has the advantage of being able to compensate for any chemistry drift caused by melting. Both seem to have good results. Denis
