The cast iron process is technically more difficult than the heat-hammer-stretch-bend-and-twist process of wrought iron. To create a cast iron piece, several precise steps are involved.
The Pattern:
First a wooden representation of the piece must be made. This is called a "pattern". The pattern creates, in every detail, the piece to be cast in iron. (It is made slightly larger than the desired size of the finished piece, to allow for the shrinkage of iron as it cools.)
The Impression:
The wooden replica, or pattern, is placed on a board with aligning pins - "mounted and gated" - in order to make accurate front and back "impressions" ...which will become the negative molds into which the liquid iron will be poured.
The Finished Mold:
We then match the sand impression of the front of our casting with the impression of the back...making the finished mold.
Molten Iron:
Next, the iron is melted to a liquid state in either an electris or gas furnace, and quickly poured into the impression or mold.
Cast Iron:
If all goes well, within six to eight hours, when the casting has cooled, we will have an iron casting duplicating our original.
