Yes or no too free cylinder heads?

Iron does stick tenaciously to clean steel. I suspect that it actually dissolves the surface and the steel and iron can mix together to weld if given enough heat.

However, soot is a good release agent on steel that is exposed to molten iron briefly. I am thinking tongs, skimmers etc. I suspect it would work on molds that were massive enough (1/4” angle?) they would pretty quickly skin the poured iron before the mold had a chance to get to molten iron temps. Steel stirring sticks and thin gauge skimmer dissolve in molten iron. I use soot on skimmers and slag tongs with good results.

Denis

 

I have never had an iron ingot stick to my ingot mold because I dust talcum powder on the mold before I pour. Bronze ingots were a huge problem sticking to the ingot mold even though there was a oxide layer on the ingot mold, so by dusting talcum powder on the ingot mold I never had a bronze ingot stick again.

 

I thought I would put in my 2 cents worth here. I process fairly large quantities of aluminum automotive parts into ingots about 7000 lbs per year. My furnace will melt about 200lb per firing, I use mostly cylinder heads, I get them about 1500lbs per load. I do strip shafts but I don't worry about valves and bolts. the iron drops into the bottom of the furnace, and the slag stays on top, the furnace tilts so the aluminum pours out between and is very clean. I still dross before I pour. When I first started processing i had ingots scanned and found that the iron content didn't change whether I removed all iron or not. The only time I had higher iron content was with pistons with rings still on them it still only made about a .5 % difference My crucibles are made from fire extinguishers that have a ceramic coating on the inside. I use them instead of normal crucibles due to weight and when they fail it is a pin hole failure. My molds are 1 1/2" and 2"angle iron,coated with ceramic. the Mag have run across has been Audi valve cover gaskets, some small engine con rods, some transfer cases ( they are marked MAG), and old VW engines.
Art B

 

A crucible style furnace with propane (to be upgraded to wmo) without the crucible big enough to fit engine heads and irregular parts. The furnace is elevated and has enough room to place 5 L metal cans to collect the clean metal as it melts and flows through the bottom hole. I put the engine head inside and let it cook. First melt takes some time, but once it gets hot it's very quick. I have to do a scrapping session these days so I'll try to take some pics and maybe some video.

 

BTW, I have bought flat-rate boxes of ingots from Master53yoda several times. He has shipped first-rate 356 ingots promptly and at a reasonable price.

Denis