cleaning up the slant six head
I'm doubting that we can get a spectral analysis of the iron to determine what elements are in it, but conceivably a high value of any of the reactive metals (Cad, zinc, tin, etc.) may be the actual cause due the the vinegar attacking and removing it from the iron alloy thereby destroying the casting's integrity. As most know, any iron is not all iron, there literally millions of versions of iron and they all have unique sets of characteristics depending on the alloying elements.
I'd love to have a scientific explanation for this occurrence, what we know thus far is an iron casting soaked in vinegar for a lengthy, but unknown exact amount of time exhibits a loss of cohesive metal properties to some considerable depth. What factors are missing? Acetic acid concentration, cast iron constitution/"alloy", and? I'm not saying that the conclusions are correct, only that absent anything concrete that's more scientifically plausible, that I'm satisfied with what we have. Not comfortable, but satisfied.Yes, I have put cast iron in vinegar for prolonged periods, without any "softening". There's a sound scientific explanation for why that is.
Yes, vinegar is a strong enough acid to attack zinc and cadmium—that's not in question here, but if it were, there's a scientific explanation for why that is, too.
Yes, I'm looking at the same pictures you are—where we differ is in what we think we see.
Me, I'll be content with the explanation of events once it has fewer gaps and soft spots than the alleged ones in the head's machined surface. I don't put much weight on shaky hypotheses, but others' opinions may vary. I think I'll just go back into lurk mode and watch how many dollars, days, and cylinder heads are consumed in the hunt for a way out of paying a reasonable hot-tank charge.
I'm doubting that we can get a spectral analysis of the iron to determine what elements are in it, but conceivably a high value of any of the reactive metals (Cad, zinc, tin, etc.) may be the actual cause due the the vinegar attacking and removing it from the iron alloy thereby destroying the casting's integrity. As most know, any iron is not all iron, there literally millions of versions of iron and they all have unique sets of characteristics depending on the alloying elements.
