Amy M. from Vermont wrote me via Ask The Pan Handler and asked: “[M]y husband is requesting an cast iron skillet with a smooth cook surface. He says that the old ones had very smooth surfaces–possibly ground down? Which (if any) manufacturer would be best suited for him? [T]hank you!”
Amy, just about all of the great old cast iron skillets have smoother cooking surfaces than do pans of current manufacture. Just take a look at the cooking surface of a modern-day Lodge skillet, for example, and compare it to the cooking surface of an old Griswold:
Both pans had been cleaned to bare iron and then heat-seasoned with Crisco vegetable shortening. You can see the difference in texture. The same is true for the bottoms of the pans:
I dove a little deeper into the issue, trying to figure out why, exactly, the surfaces were different in texture. Obviously, one major difference is that the process is now largely automated, whereas human hands polished and ground the great old vintage pans. I found a Lodge foundry video which proved to be very helpful in learning more about how modern-day cast iron skillets are made. As you can see in the video, once the pans are released from the sand molds, they undergo a process where they are basically machine blasted to remove all remaining sand, and then blasted again to assist in cleaning. The cooking surface does not appear to be machined or polished at all.
Conversely, as shown in the little vintage pamphlet below from the Favorite Stove and Range Company,1 skillets were tumbled, then polished with a grinding wheel (or milled), which resulted in that beautiful glassy cooking surface seen on so many of the great old pans.
I was also provided two photos2 which were taken in 2003 at the Wagner foundry, prior to its closing. The photos show the grinding stone that was used on the cooking surface of a griddle during the polishing process. The red arrows point to the handle of the griddle, and to the grinding stone in the right photo. You can see even in this photo that the cooking surface is much smoother than that of a current-day Lodge.
I have also read that the texture of the sand used in the sand molds was more dense than that used at present.3 This makes sense when you think about it. Given the process by which cast iron skillets are made, the texture of the sand in the sand mold would replicate the texture of the product once it is removed from the mold.
I found an interesting British instructional video that showed how small iron pieces – there stovetop burner pates – were manufactured in the 1940s. I imagine it was a similar process in the United States. It provides a nice overview of the sand mold casting process.
Wikipedia also has a nice discussion about the sand casting process, with some nice illustrations that make the process easy to understand.
Amy, thank you for your question. It provided a great learning opportunity for me, and hopefully the information will help some of you, too!