Making Molds for Glass Bottle Stoppers and Glass Feet

I threw several rings to make a glass foot for the ceramic bowls and plates. I also made several stoppers for preparation of the glass stoppers.

I place the forms into a bed of clay at the leather hard stage and apply mold soap to all clay showing that acts as a resist for the plaster. The mold soap ensures that the plaster will not stick to the form and is able to be released freely.

I then encase the pieces with the cottle boards and brush the mold soap on the boards as well.

Once I measure the width length and diameter of the pieces I can measure my material for the plaster and pour the plaster in.

I apply the same method to the foot rings.

The mold is now set up and ready to be turned over.

Here is the reversal side of the mold.

I take out all the clay inside the forms so that I can stack the glass on top of the mold and let it drip through the holes during the firing.

Here is the mold for the foot rings

Preparing Stoppers for Bottles

I have created a few bottles intended for olive oil and created ceramic nobs that fit the form. I wanted to create a glass stopper that is inserted in the ceramic nob, so when you go to open the bottle, you are surprised to find a glass stopper inserted inside.

Here is a nob for one of the bottles,

I cut out a hole or insert at the bottom of the nob piece in order to fit the glass stopper after it has been bisqued and glazed.

I then measure the diameter of the insert before it is bisqued and take into consideration the shrinkage that will happen once the piece is bisqued and then again once the piece is glazed. It's important to know how much the piece will shrink in the firings in order to create the correct size for the glass that will fit into it. The glass will not shrink as much as the clay.

Bisquing Plates and Bowls

Here are some plates and bowls I made placed in the kiln and ready to be bisqued.




I am using a slow firing schedule that is fired using 5 ramps. Each ramp slowly preheats the kiln to avoid reaching the boiling temperature of 212 degrees Fahrenheit to quickly.

During the first of the five ramps, I take the kiln to 150 degrees at 80 degrees an hour and hold for four hours. This should ensure that the wetter pieces in the kiln dry out enough before the kiln reaches it's highest temperature of 1957 degrees.

Creating Another Foot

Unfortunately, the foot that I made for the bowl blew up in the firing due to not preheating the kiln for long enough. The piece was slightly wet and I should have set a longer preheat in the firing schedule to assure it would come out in one piece.

So, I decided I had three options. One, to throw another foot, bisque it, glaze it and cold surface it, or attach it back on using epoxy. Two, to throw another foot, make a mold out of it and cast glass in. Three, throw another foot, make a mold of it and slump glass into it. I tried all three and the most successful one was the ceramic foot.





After the piece blew up in the kiln, I had to grind down all the sharp edges and make it as smooth and flat as possible so the secondary foot would fit snug.

Here, I threw a hallow ring for the foot, sliced the foot in half and put both halves faced up to create a mold for the slumping process. I placed the convex side of the form facing up so I would have the reversal or concave side of the form in my mold. Once the mold was dry enough, I have the shallow form revealed which makes it easier to slump the glass into.

This method did not work as the glass cracked during the firing and split apart.

The third attempt consisted of throwing another hallow ring, or foot, taking the same shape and design as the other ones. I placed this foot facing up in order to make a mold to cast glass in. Once the plaster is poured over the foot, I will let it set up and take shape. I then will carefully flip the mold over and take out all of the clay to reveal the shape of the mold. Measuring the amount of glass I need consists of measuring the cubic inches of the clay foot I just took out of the mold. Once I have the right amount of glass, I am able to cast the glass in the mold by stacking the glass in a flower pot. I am using a drip method by hovering the pot above the mold with stilts, and letting the glass drip through the hole of the flower pot and into the mold. 

Unfortunately, this method didn't work either, the glass wasn't able to flow through the entire mold due to the thin areas (the curved area) in the foot. 

Cutting and Grinding Glass

Once the molds were ready to go, I cut my glass using a ruler for support and a glass cutter. 

I placed my molds into a kiln and placed different iridescent glass pieces on top of the molds. The temperature reaches about 1775 degrees Fahrenheit  during the slumping process. For iridescent glass, you must place the iridescent side facing up so that you are able to achieve that color. 

Once the glass is slumped, I am able to cut the excess glass around the shape using a glass cutter and pliers. 

I decided to slump glass spoon rests instead of making glass spoon heads. I slumped the glass spoon rests on ceramic bisqued bowls I made in order to take the shape. After the firing, I began to grind the glass down with a glass grinder into the shape I wanted. 

Testing Glass Spoon Heads

Testing Glass Spoon Heads

Before I decided that the glass spoon heads would be too uncomfortable to eat off of, I created several spoon head molds. I wanted the spoons to have various textures on them to heighten one's senses and awareness to what they were eating off of. I embedded the clay spoon heads into a bed of clay at the leather hard stage. I then sealed the cottle boards to avoid and plaster from leaking out.

Once I measured the height, width and depth of the spoons, I was able to measure out how much material I would need to create the mold. 

After I let the molds set up for a few hours, they were ready to have glass slumped into. 

Soup Tureen

Soup Tureen

I started off throwing a 14 lb bowl and created a flange for the lid to sit on. Measuring the diameter of the bowl, I was then able to create a lid for the tureen. I knew that I wanted the spoons to hang from the bowl and designed hooks out of nichrome wire. I wanted the soup tureen to stand tall to allude to it's importance. I threw a separate foot and attached it to the bottom of the bowl. I also wanted the curves of the spoons to mimic the curves of the bowl. 

Here, I am adding the nichrome wire hooks, and playing around with the shape of the wire, which will reflect the design of the bowl.

I am seeing how the spoon looks as a whole and determining the height and shape of the spoon.

After I designed the bowl, I slowly let it dry out to avoid any cracking.