Diamond Logo question?

[Baggsy]

I perused the Blue Book last night trying to find examples of the Diamond Logo on pieces other than the griddles.  I came up blank, but I do that alot.  Was the diamond logo used on anything other than griddles?  What was the 'Extra Finish' that they put on them?

[Harry Riva]

I'm not sure about other cast iron pieces but the diamond logo was used on at least some of their aluminum aluminum pieces, but had different words than the "extra finished.....". I think the Extra Finished referred to the finishing work Griswold used after the piece was removed from the mold and not to anything that was applied to the piece.
Harry

[Troy_Hockensmith]

Baggs,
Extra finish, as I understand it, is the process of finishing the inside cooking surface. On a lot of pieces you will see what appear to be grinding marks on the inside that smooth out the cooking surface. One the piece is removed from the mold they go to work on smoothing out the cooking surface. Being an extra step in the manufacturing process it drives up the cost of making a piece so the process has went to the wayside. Next time your at a wal-mart take a hard look at the cooking surface of a new lodge. You will see it is rough and grainy and compare that to one of your "finished" skillets. You will see the finished surface is much smoother and more easy to season and maintain.  

[C. Perry Rapier]

And with 50 years of daily use the cooking surface will fill in, then you can have a surface like a griswold. Then some collector can buy it. He will then take it home and strip it and then get on the internet (or whatever will be in use) and contact Greg and Steves grandchildren, or great grandchildren, and ask them how come the cooking surface is so bumpy as compared to the skillets made by Wagner and Griswold.

[Steve_Stephens]

Greg has a good start on building a grandchild family but I haven't even begun to think about it.  Actually, I bypassed that stage in my life.  

Troy, the "extra finish" is, as I understand it, the extra grinding done on cooking surfaces on the pieces it was done on.  And the grinding was just that-done with a grindstone which may explain why some pans have a finer grinding than others.  I would think a new stone would produce rougher, deeper grinding marks than a worn stone.  

"Plain finish" would be "as cast" rather than "ground".   I don't know if Lodge currently makes a ground finish as an option but they have in the recent past as well as Wagner on their 1891 Original line.  It seems that it is up to the store to order and carry whichever finish they want to with the plain, as cast finish being cheaper so maybe that is why you see those more often.

An ERIE in a diamond (but not the Extra Finished diamond mark) also appears on some early Griswold egg poachers (962 aebleskiver pans-Haussler p.106).  Why the mark was used so little I don't know.

Steve

[Troy_Hockensmith]

Steve,
I agree. Some do seem to be a "finer" finish than others. I would love to have seen the equipment they used to finish those surfaces. I don't know the process but it seems it would have been mighty hard with a stone and that they would have had more specialized equipment. I picture something more like a modern engine hone. It looks like a hairbrush that the teeth go 360 around the handle and there are little abrasive balls on the end of each tooth. The teeth are long and made with flexable wire. Some thing like that would have been far more effective for getting the nooks and crannies. I don't know or pretend to know what they used but I have thought about it before and think a hard wheel would have been tough to get some of the markings I've studied in the skillets I have seen. I think a wheel is definitly what was used to remove the gate markings but if you've done any grinding at all it's pretty tough to get a finish like the ones we see in the skillets. I've also thought about having a stone sized for each skillet or oven or what ever but that doesn't make sense to me as that would be a lot of speacial stones and they would wear pretty quickly requiring a lot of replacement. Something like I described above would be more effective for variouse size and shaped items. If the skillets I have studied were done with a stone they were definitly masters of a grinding wheel.    

[Steve_Stephens]

Troy,
If you saw the apparatus used to grind the skillets and many other pieces you would understand easily.  Maybe you can visualize what the process looked like by reading what Favorite had to say (and illustrate-but I can't send a photo) in a c.1920's catalog on their hollow ware:

"The ware next goes to the grinding department where special machines, designed and made by us exclusively, grind and polish the interior of the ware.

The ware is revolved at a high speed in one direction, and the grinding and polishing wheels set at angles revolve in the opposite direction as shown in the illustration on the following page (can you see it?).  The speed of the two surfaces revolving in opposite directions is so great that only the toughest castings would withstand the strain.  Several manufacturers do not attempt this grinding process, because the ware will break in the attempt.   It is necessary, however, as it removes the scale from the inside, exposing the pores of the iron making it possible to season in the ware in a way that could not be done otherwise.  This accounts for its wonderful efficiency in cooking.

After being polished all pieces of ware are given a coat of lacquer to guard against anything that would mar or interfere with the brilliancy of the ware during the packing and shipping."

I am not sure that cast iron is really porous and the mention of it being so might be a marketing ploy.  I really don't know and have not studied the properties of cast iron.  And what does the "scale" look like that the grinding removes?  Is the scale left on the unground parts of the piece or is it removed during the tumbling process (also explained) with thousands of "stars" in which the ware is rotated with in a drum?

The grinding machine reminds me of a brake drum grinding machine.  The operator holds a large diameter wheel which he turns to make the stone go across the piece's surface.  At least that is what it looks like to me.

Steve