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Hexagon molded glass by Marion le Red, Windmasters Hill Atlantia.
There are several pieces from the 400 AD to 1300 AD that have a simple hexagon pattern mold blow glass. I wanted to do a hexagon pattern mold for these. The two bowls below are from the Corning Museum of glass CMOG the blue one (first one) 1100-1299 Iran the second on is from 800-1299 Islamic. The 3rd cup is at the Getty Museum and is from the 4th century Rhine area (See links in the reference section as the file was too big with all of the pictures to save)
There is only one existing mold from period that is made of clay in the CMOG collection. But from the traces left by the mold process on the glass we know molds have been made of plaster, clay or metal and we have pictures of dip molds being used in period. Making the mold was the hardest part of this project. In all the examples that I have found the hexagons are raised into the glass and the negative space between the hexagons go out. My first thought was to do a clay mold that I stamped hexagons into but after thinking this through that would leave hexagons coming out not going into the glass.
I then tried to draw the hexagons inside of the mold drawing or scribing the hexagons inside of a concave space was not easy. I was not able to get uniformed hexagons. I also thought the negative space between the hexagons was too small. Both of these first molds I tired to fire while still wet in a camp fire and they exploded.
After much wondering and thinking on this I came up with the idea that the hexagons were made separate and placed into the mold. Which leaves uniformed hexagons and un-uniform negative space which I was seeing in one example. This led me to the hardware store where they sell bathroom titles in a hexagon shape. So, I pushed 1 in hexagons in to a concave free hand mold. Since the mold is concave and the hexagons were flat the space between them was not even. I started with cup mold by the time that I finished putting the hexagons in it was very much a bowl mold with a wide surface at the bottom rather than a small surface.
I did not fire this mold but let it dry for a week, I then took that mold to the glass studio. I was amazed when I blew into for the first time the lack of sticking and clay that adhered to the glass.
Glass blowing process (heavy with glass terms please see appendix for definitions)
These bowls were blow with color rod as I wanted a consistent color that translucent. I started by placing blocks of color into a warming annealer to pre-heat them to stop the color from cracking. To start the blowing process, I made a collar of glass on my blow pipe. Is done so that there is plenty of glass to create a warm area at the end of the pipe with glass but to only have small skin of glass on the end of the pipe for picking up color. To do this I jacked a majority of the glass off and then heated the pipe in the glory hole. While heating the pipe I blew out the end of the glass so that I had a think lay of glass on the head of the pipe but a good amount of glass on the sides of the pipe. I used the jacks to make sure that there was nothing blocking the whole in the pipe.
I then went to the color pick up annealer and picked up the color by touching the end of the pipe to the color I wanted. When color is concentrated and hot it all looks the same so knowing which color you are picking up means you know where you put your color in. Once the color is picked up at the bench the color is brushed with a reed bush to remove any dust or refractory that may have adhered to it in the annealer. The color is then heated and moved into a point. When doing this you want to make sure that there is not a gap and the glass is smooth and uniformed. Any place that that there is an indentation could create bubbles in the glass when you gather over the color.
Next, I gathered over the color, used the block to smooth the shape and allowed the heat to sync into the piece. Next, I heated the glass and blew a starter bubble. I then chilled the bubble so that I could do a 2nd gather over that with clear glass. This gather was a strip gather allowing excess glass to fall off the piece in to a bucket of water.
With all the glass that would go into the piece on the pip I then used the block to help shape and smooth the glass. I then heated it in the glory hole and started to blow the piece. I used new paper and jacks to create a flat bubble the was wide and close to the pipe. I put in a starter jack line or constriction area near the pipe so when I blew into the mold it was not too big near the pipe that I could not get the jack around it.
I then got the piece hot and dropped into the mold. I blew in the blow pulling up on the pipe so that the bottom half of my piece took the hexagon shape of the mold. When I came out of the mold I went to the bench where my partner helped to brush any mold bits and clay off the glass. At this point the glass looked a little like a brain with the hex shapes in it but it was not spherical. The brushing also does not help to keep the glass spherical as you push in and the glass moves. My next step was to make the glass spherical again after re-heating I blew and used new paper to make the glass spherical.
The first few tries I marvered the glass and removed the outside texture of the hex mold. The tires that I like the results of I used the news paper which allowed me to get the shape without removing the mold.
I then made sure the jack line was good and created a flat bottom on the bubble to start the shaping of the bowl. In creating the bottom, I tried to put a hex in the center of the bottom and that the hexes where uniformly up the side of the piece. With the purple piece I did this all myself, I believe the bottom was a little off on that piece and not flat because of it.
My partner then made me a punty and we transferred the bowl from the pipe to the punty so I could open the top of the bowl. When placing the punty if the bottom was centered on a hex then it was easy to center the punty as there was marked spot for the bottom.
I then re heated the top half of the bowl and used a sofietta this puffs out the top of the bowl and creates a thinner lip. After using the sofietta twice I then pulled out the lip and opened the bowl into it’s final shape with a curved lip and relatively straight side walls.
First few tires stayed on the Punty and I did not get a good picture. They also had the hexs marverd out.
Examples of bowls that did not come out good.
Bowls that took the mold well and I did not heat the pattern back out of.
What I will do the next time that I would do differently.
When I created the mold the bathroom titles kept making the mold wider than I would like. I need to create a tall and slender mold to be able to have the whole piece have the hex pattern also the hex pattern should have gone up the whole bowl not just the bottom 1/3 of the bowl. The hexs are also large for a period piece they would need to be ½ inch or smaller. To do this the next hex mold I will start by making clay hex’s by rolling out the clay and cutting the hex’s then after they have dried placing them in a taller and narrower mold.
Reference pictures:
Bowl 1 https://www.cmog.org/artwork/bowl-494?search=collection:9785143f6e08462d6c3a7364a4c46b80&page=2335
Bowl 2 https://www.cmog.org/artwork/bowl-509?search=collection:f875b642681ab9c90a316ffc17e6d40d&page=26
Cup http://www.getty.edu/art/collection/objects/221729/unknown-maker-cup-roman-about-4th-century-ad/
Websites:
Corning Museum of Glass
https://www.cmog.org/collection
Books:
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