brass door knocker pattern

Our experience in the foundry making our brass door knocker didn’t start in the foundry at all. As a matter of fact there is a lot of work to be done before the foundry work can even begin. First of all we need something to cast. We call this the pattern.

It seems that our brass door knocker must first be made out of wood. At least the pattern for it will be.

Our completed door knocker requires two castings. One casting for the body and another for the clapper. We will need a pattern for each casting.

Before we can make a pattern we need to come up with a design. Drawing it out on paper is good, a computer drawing program is better. We need to create a scale drawing that shows what the final product will look like. Every detail that we can imagine should be included in the drawing. This will help us find problems before we begin.

When the drawing is completed we can trace the outline on a piece of wood to be cut out sort of like a silhouette. The rest of the details will need to be carved and filed in until an exact 3-D replica of the part is achieved.

The pattern becomes one of the most important components in the casting process. All the rest of the work creating a quality product depends a good properly made pattern.

It must be strong enough to stand the mold making process. It must be shaped with the proper tapers to exit the mold during preparation. There are a lot of factors that go into getting the pattern just right. It may take a couple trial castings to get all the bugs worked out.

When the pattern is ready we can progress to the next step in making our brass door knocker. Taking it to the mold shop where the sand mold will be made. That is the subject of the next post coming soon.