I have recently stripped the paint and rust from a 1938 Rock Island 593 4” vise in my electrolysis tank. When comparing it to a Columbian D43 1/2 I did the same thing with about a year ago, the bare cast iron of the two vises seems to be different. The Rock Island being much lighter and shinier, vs the more dull and dark Columbian.
I was actually anticipating the bigger Rock Island would look similar to my Columbian because I assumed they would have been very similar cast iron underneath. Was this a wrong assumption? Is there something else that could cause the colors to vary so drastically?

I was actually anticipating the bigger Rock Island would look similar to my Columbian because I assumed they would have been very similar cast iron underneath. Was this a wrong assumption? Is there something else that could cause the colors to vary so drastically?


