Posts Tagged ‘casting clay’

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The First Step

November 22, 2012

Now on to the making of the ornament.  What you need to do is make an exact replica of the ornament in plaster.  The plaster ornament has to be as perfect as possible with no bubbles or bumps or uneveness any where.  I will use this “model” to make a rubber mold from, that I can then use to cast all my working plaster molds.

I am using an old plasterers technique to make the plaster blank with rings around it’s edge.  A lot of the decorative trim in older houses used to made with plaster, moldings and the circular ceiling details above chandeliers.  I’m using that idea only smaller to make my blank.  Here is the first one I made but I wasn’t happy with the result.  It was too flat.

I want the rings to be more domed.

Here is the second blank with better rings.   The brass template swings around the post and scraps away the excess plaster to leave the ringed model.  I had to apply about 3 coats of plaster to get the final model.

The rings are more domed.

Here are the two side by side.  As you are about to see, patience needs to be in great supply.

I used the one on the right.

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2010 Limited Edition Christmas Ornament

November 25, 2010

Our 19th Limited Edition Christmas ornament is now finished and in our shop. I thought over the next few posts I would show what is involved in making this come about.

The Finished Ornament

After deciding on an idea, the process starts with a drawing. We decided on a poinsettia an image linked to the holidays.

Rings are cut into a plaster slab, the drawing is transferred with carbon paper and then the image is carved into the plaster. The progress of the image is checked frequently by pressing Fimo into the depression.

When this stage is finished, a casting is made to get the image and the rings raised up. The lettering is carved into this side, so the glaze will pool down in the letters when fired.

Plaster is now cast on this carved and lettered image to get a slab with everything reversed. Pam pressed Fimo on the finished slab and modeled an ornament complete with lug, which takes the hole for the ribbon. Plaster is then cast on top of this Fimo model.

Now I will pour a two part rubber compound over the plaster to get a rubber master mold. From this master, all the plaster working molds will be cast.

In the next post, I will show the casting process.