Video showing how to make a plaster mold

This video isn't made for glass fusing, but it really shows how to make molds and if you use the correct glass mold making materials, you can easily create glass fusing molds this way! 

Click here to watch this mold making video.

Video for Creating a plaster mold for Pate De Verre

Hi readers, are you wondering how to make easy plaster molds for Pate De Verre?  Watch this YouTube video to see a very simple, yet effective way to quickly make your own plaster molds!  
This video was made by Bobby Wadey.   

Click here to watch the video!

Bullseye box casting tutorial

To view the original article and pictures follow this link Bullseye Glass Tips Sheet 5.

This Tip Sheet will introduce you to ways to create a reverse relief cast 
glass object with the optical clarity of a furnace casting, using plaster silica 
design elements in an open face mold assembled from vermiculite board and 
other refractory materials. In this process, there will be less waste than with 
traditional kilncasting processes and the majority of the mold will be reusable. 
The molds themselves will be of uniform thickness, allowing for even heating and 
cooling. Furthermore, the molds will not fail at casting temperature, which is 
among the most common concerns in kilncasting and one of the reasons that there 
is such a boggling array of mold recipes in use. The results are typically much 
cleaner and more predictable than kilncasting in most of the traditional methods, 
and the process is extremely easy to repeat for the purposes of making editions or 
production work.


Origins of the Method
This method of kilncasting developed as an outgrowth of an artist exchange project
in our Research & Education department with Mexican artist Rafael Cauduro. Cauduro 
had originally come to the factory to work in methods known as Painting With Light, 
but quickly became intrigued with kilncasting processes and began to make large-scale 
cast glass sculptures using traditional “monolithic” or one-piece refractory molds. 
The fabrication, handling, and technical challenges posed by making and firing 
these molds ultimately led the R&E team, assisted by Ray Ahlgren,* to begin researching 
other ways of building the molds. After the conclusion of the project, this research 
continued. TipSheet 5 will lead you through the processes that were subsequently 
developed.


Where you are going:  The finished piece
The end result will be a solid block of glass with relief imagery in the back of the 
piece that when viewed through the flat front creates a nearly holographic image. 
The top surface of the piece will be glossy and smooth. If carefully planned and 
executed, the top perimeter will have a soft, bullnosed edge. Occasionally, some 
cold work may be necessary or may be a tremendous advantage in the finished work. 
The finished block will measure about 19.5 x 19.5 x 4cm. These dimensions may be 
enlarged by adapting the general guidelines and adjusting the firing schedule.



Materials Needed
Glass: Because clarity is essential to creating a reverse-relief casting, we recommend 
using any of Bullseye’s 1800 series casting tints in billet form. Because they have 
smoother surfaces and less surface area by weight than other forms of glass, billets 
will trap less air than frit, powders, or sheet glass, and therefore create fewer bubbles
in the final piece. Billets are preferable not only for the clarity they produce 
in the finished casting, but also because they are easy to handle, cut, and load into the 
mold. The 1800 series glasses are formulated to gradually transition in color saturation 
as they go from thick to thin, making them ideal for this and other casting processes.
Other materials:
• Clay and tools for modeling design elements
• Metric scale
• Metric ruler
• Bullseye Hydrogel N (8242), or similar moldmaking material
• Mixing containers
• Bucket of water for initial clean-up
• Bucket of water for rinse
• Bullseye Vermiculite Board (8240)
• Stainless steel (deck) screws
• Bullseye Investment (Plaster-Silica) (8244), or similar refractory investment material 
• Fiber paper (7036)
• Vaseline/petroleum jelly
• Murphy Oil Soap
• 946 ml Ziploc food storage box, or equivalent
• Garbage can with liner
• Self-lubricating glass cutter
• Hammer




Notes on Metric measurements
For the sake of simplicity, all units of measure in this TipSheet are Metric. 
The decimal format of the metric system and its direct and simple translation from 
length to volume to weight in water makes it a superior system for laboratory work.
in the metric system: 1 cubic centimeter (cm3) of water = 1 milliliter (ml) of water = 
1 gram (g) of water.  If the interior of an empty box measures 20 x 20 x 2.5 cm, 
then this interior has a volume of 1000 cm3. 1000 cm3 of water is equal to 
1000 ml of water, which is equal to 1000 g of water. Bullseye glass is 2.5 times denser 
than water, so it would take 2,500 grams of Bullseye glass to fill this same volume.

Making a mold for multiple copies of a model
preparing a model using clay or a found object:
Prepare a model no larger than 5 x 5 x 3 cm using either water- or oil-based clay. 
This model will be used to make the design elements that will create the reverse 
relief imagery in the final casting. Water-based clay is usually softer than oil-based
clay, can be modeled very quickly, and can be reused and recycled. However, it 
will dry out over time and will shrink as it does so. Oilbased clay is usually firmer,
does not dry out, holds fine detail very well, is reusable, and releases very easily 
from most mold materials such as alginate, rubber, and silicone. Found objects 
may need to be coated with a release, such as Vaseline or Murphy Oil Soap.



For this particular process, the model itself should have minimal undercuts. 
Undercuts on found objects can be filled in with clay. The very bottom portion of 
these design elements will end up being submerged in investment material to 
hold them in place in the final casting process, so plan accordingly.




Preparing to pour a mold:
Place the model into a box with a minimum of 15 mm
of space all around it; a 10.5 x 10.5 x 9 cm flexible plastic food storage box (Ziploc)
with a slight draft to the sides works well. The box serves as a coddle system, or 
a set of dams, into which you will pour the alginate to make the mold. Use something 
like petroleum jelly to secure the model to the bottom of the box to keep it from 
moving or floating once you have poured in the mold material.


Types of flexible mold material 
for casting multiple copies:
Hydrogel N mold compound is a type of alginate that is fairly easy to mix and sets in 
5-10 minutes. It is somewhat weak with a short working life and will dry out 
and shrink over a couple of days, but if kept in a sealed container and treated carefully, 
it will usually last a few weeks.

RTV Rubber (Room Temperature Vulcanizing) is activated at room temperature but can have long set times and often takes 24 hours to cure into a very durable, very strong material.
For the sake of expediency, we have used Hydrogel N to illustrate this TipSheet.

Mixing hydrogel N mold compound:
Measure box/coddle system—including 1.5 cm above the model in the calculation. 
For our specific box and model, this is 10.5 x 10.5 x 4.5 cm, which equals 496 
cubic cm, which means that it will take 496 grams of water to fill the box to the 
appropriate level. The manufacturer of Hydrogel N mold compound recommends 

mixing it 3 parts water to 1 part Hydrogel N by weight and adding the mold 
compound to the water, but we have had good success mixing it 4 parts water to 1 
part Hydrogel N by weight and adding the water to the Hydrogel. For our project, 
then, we will need 496 grams of water and 124 grams of Hydrogel. We have 
had the best success mixing this with a spatula in a bowl using a folding, not a beating 
motion, to avoid creating bubbles in the mix. Work in a well-ventilated area and 
wear a NIOSH-approved respirator whenever working with powdered materials 
or dusts.


Pouring the hydrogel:
Be certain that you are working on a flat and level surface. Pour to one side of the object
in a flowing motion to keep air from getting trapped on the surface of the model. 
Vibrate the worktable so that the air bubbles don’t get stuck to the model.


Cleanup:
Using water immediately makes a mess. Allow remaining Hydrogel to dry in the
container and then immerse in bucket of water for initial clean up. Once cured, it is 
possible to peel the Hydrogel out as a skin. Never pour into a sink.

Removing the mold from the coddle box:
Turn the coddle box upside down on the work table and squeeze and push the flexible 
walls to let air into the sides until the mold drops out. Turn the mold over 
again and squeeze it and push carefully to force the clay model out. You now have a 
flexible mold for pouring multiple copies of your model in another material.



Making design elements out of refractory mold material
Many different refractory mold (or “investment”) materials and recipes exist. In our 
factory Research & Education department, we use a simple mixture of 50% #1 Casting 
Plaster and 50% silica flour (295 mesh) mixed by weight.


Measuring mold material:
Measure the original model and overestimate its size; it is better to discard some 
inexpensive investment than to run out and have to quickly mix more. Our model is 
roughly 5 x 5 x 5 cm = 125 cubic cm. Referring to the Investment Ratio chart on page 8, 
we can add together the amounts of material needed for voids of 100, 20, and 5 
cubic centimeters to get the proper quantities of water and investment required for 
our 125 cubic centimeter void. This means that we will need 79.99 grams of water 
and 139.98 grams of investment. Weigh these materials in clean, dry buckets. Remember 
to work in a well-ventilated area and wear a NIOSH-approved respirator whenever 
working with powdered materials.


Mixing investment material:
Steadily sift all of the required investment into the water. An island of dry material 
will begin to form once you have sifted most of the material into the water. Allow 
the investment to fully hydrate/become saturated. If left alone, the investment can 
sit for quite some time. Once the mixture is saturated, dip your hand in and 
break up any chunks. Feel the consistency. You want a creamy texture. Mix the 
investment by hand for 3–5 minutes or with an electric mixer/drill for 1–2 minutes. 
This will cause the plaster to begin to work so that it will subsequently set.


Pouring the mixed investment into the mold:
Be certain that you are working on a flat and level surface. If you have a lot of fine detail,
begin by brushing some investment mix into the details in the mold, which will 
break the surface tension so the mix can go into the details. Aim for one place in 
the mold and pour in a flowing motion to avoid creating bubbles. Once 
you have finished pouring, vibrate the work surface to make certain that no air is 
trapped within the details of the mold.

Cleanup:
Clean investment mixing buckets right away. Old plaster in mixing buckets, on hands
and/or on tools will cause subsequent batches of investment to set before 
you have a chance to pour them. It is good to use black
or colored buckets so that you can easily spot old plaster in them. Never pour
investment into a normal sink as this will clog your pipes. Pour excess investment into 

a garbage can that has a liner in it. From there, have two buckets of water to use in your 
cleaning operation: one bucket for cleaning and scrubbing the mixing buckets and one 
bucket for rinsing them. When these buckets become too filled with waste investment to 
continue using them, allow them to settle, then pour off the excess water and dispose 
of the waste investment in garbage bags.

After investment has set up:
It usually takes 5-20 minutes for the investment to set. Lightly touch the surface of the 
investment to test its hardness. Once it has set, the plaster/silica design element can be 
removed in the same fashion that the clay model was. Immediately after setting, the 
design element will still be a little soft, which means that it can be easily modified 
with simple clay tools at this point. After the design element hardens, it can still be 
modified, but you may need to use power tools for the sake of speed.  Store the 
alginate/Hydrogel mold in a closed container for later use, being careful to keep 
it from drying out.





Building the box mold with vermiculite board

Vermiculite board:
Vermiculite has a bad reputation because it is often mined in the same places as 
asbestos, which can contaminate the vermiculite. Bullseye Vermiculite Board comes 
from a mine that is certified asbestos free. It is stronger, more durable, and less 
expensive than most fiberboard and can be cut and tooled like wood or particle board. 
Work in a well-ventilated area and wear a NIOSH-approved respirator whenever 
generating dusts.  If you want your finished piece to be level and square, it is 
important to cut the vermiculite boards accurately. Also, pre-drill and countersink 
screw holes so the board does not bloat or blow out when you screw it together. Use 
stainless steel screws to put the mold together as they will hold up to repeated firings 
without flaking. Do not use galvanized steel screws because upon firing, the galvanization 
will release toxic fumes and the screws will flake and cause contamination in your kiln.
Cut two long side boards at 25.5 x 9 x 2.5 cm, two short side boards at 20 x 9 x 2.5 cm, 
and one base board at 25.5 x 25.5 x 2.5 cm. Lay the boards out as an open box 
and pre-drill holes in the flat surface of the long side boards to connect them to the ends 
of the short side boards using a bit that has a diameter slightly smaller than the diameter 
of the stainless steel screws. Be sure to drill your holes on center to avoid blowing out the 
side of the board. Then screw the sidewalls together. Next, set the base board on top of the 
assembled side boards and pre-drill holes to join it to the sides, and then screw it together. 
Then take the entire box apart and fire the vermiculite board at a rate of 500°F (278°C) 
per hour to a temperature of 1580°F (860°C) or about 55°F (30°C) higher than the temperature 
at which you will cast the glass. Hold at that temperature for half an 
hour, and then crash cool the kiln.Once the boards are cool, take them out and 
reassemble the sides using the stainless steel screws. Cut a piece of 3 mm fiber paper at 
25.5 x 25.5 cm and set it on the base board, then set the assembled sides on top of the fiber 
paper, and screw the box together. Line the side walls with 3 mm fiber paper, making sure 
that it fits tightly, without bowing or leaving gaps in the corners.

Affixing design elements within the box
The design elements must be held firmly in place for the glass casting process. To hold 
them, a shallow layer (or “bed”) of investment is poured into the bottom of 
the box around the design elements.  Hydrate the plaster/silica design elements by soaking 
them in water until the bubbles quit rising (5-10 minutes). This helps to keep the
plaster/silica bed from sucking in around the design elements due to differences in 
humidity. Arrange design elements on the interior base of the box. Check once again to make 
certain that your work surface is flat and level.

example
Measure the inside of the box to determine the appropriate amount of investment
material needed. Our box is 19.5 x 19.5 cm, and we need enough investment to 
fill it about 0.5 cm deep. Thus, the investment needs to fill a void that is 190 cubic 
centimeters. Referring to our investment (plaster/silica) mixing table you will see 
that there is a batch listed for 200 cubic cm, which will be more than enough.
Mix the investment according to the previous directions and pour it quickly and
evenly. Avoid pouring the mix directly onto the design elements or the side walls. 
Vibrate the work surface to make the investment level out.Set aside the box mold 
for 24 hours to make sure that all of the plaster/silica components of the mold have 
cured to an adequate hardness. As with the design elements, you may choose to
modify the affixing layer of investment.


Selecting glass
You may select any form of Bullseye glass to fill the mold (billet, cullet, sheet, frit, etc.), 
but the form that you select will have a direct impact on the clarity of the 
casting. The smaller the form of the glass, the more air bubbles in the finished piece, 
the less optical clarity. Powders and fine frits will create so many air bubbles 
that even our Crystal Clear 1401 will appear milky white and opalescent when used 
at this 4 cm thickness.Because this is a reverse-relief casting and the intention is to see 
the imagery created by the design elements through the surface of the finished piece, using 
billets will give you the desired clarity.

Calculating glass to fill the mold:
Measure the inside of the box mold. Then figure out the cubic volume. Use a specific 
gravity of 2.5 for Bullseye glass to calculate how much glass will be needed to 
fill the mold to the desired thickness. (Bullseye glass is approximately 2.5 times 
heavier than water.) 


Our box mold:
19.5 x 19.5 x 4 cm (desired thickness of casting) = 1521 cm3
1521 x 2.5 = 3802.5 (grams of glass needed)
This does not account for the displacement of glass caused by the design elements.
If you would like to account for the displacement caused by the design elements or if you 
have an irregularly shaped mold, you can use rice for a more precise measurement. 
Fill your mold with rice to the desired thickness of the casting. Then remove the rice 
and decant it into a container. Level the rice, and then mark the level. Remove the rice 
from the container, and weigh the container. Then fill the container with water 
up to the former level of the rice, and weigh it again. Subtract the weight of the container 
to get the weight of the water. It will take 2.5 grams of Bullseye for every 
gram of water.Use a reliable scale to weigh out the amount of glass you will need.

Cutting the billet:
Use a self-lubricating glass cutter to score glass and about the same amount of pressure 
required to score 3 mm sheet glass. It is always easiest to break the score if it is made 
along the centerline of the piece of glass. In other words, cut the billet in half, then in 
half again, to get the appropriate sizes to fill the mold.


Find the score line and break with big running pliers. Or hold the billet in a gloved hand 
and use a hammer to open the score by tapping on the back of the glass underneath the score 
line. (This does not take a lot of force; a tap exactly under the score line will cause the 
score to open cleanly.) Hold the billet low and over the table so it does not fall on your 
foot. Remember to wear eye protection.

Loading the glass into the mold:
Clean and dry the glass thoroughly, making sure to remove stickers. Any glass that is 
going to be lower than the thickness of final piece can be against the mold wall, but 
be careful not to indent the fiber paper because it will create a bump on 
the finished glass piece. Stack the rest of the glass into the center of the mold.


Loading the mold into the kiln:
Make sure the kiln is level and make sure the mold is level. Set the box mold on kiln 
furniture/posts, establishing three points of contact at least 2.5 cm from the floor of the 
kiln. This will allow heat to circulate all around the mold. If you would like to
intentionally create a wedge shape, you may set up the mold on an angle; but make 
certain that you have enough glass to cover the design elements, and that you adjust your 

annealing schedule to accommodate for the thicker area in the casting. If, for example, 
you would like a wedge that is 5 cm on the bottom and 2.5 cm on top, you will want to 
support the end that will be thicker on 2.5 cm kiln furniture, and the end that will be thinner 
on 5 cm kiln furniture, and then calculate the glass as if you were casting a rectilinear 
volume with a thickness of 3.75 cm.

Firing the piece
Vent the kiln at least up to 1100°F (593°C) to make certain that all of the moisture has
escaped the kiln. Plan to be present when the kiln is at casting temperature, and visually 
inspect the piece to make sure the casting is going as planned. If unwanted bubbles 
are present on the surface or just below the surface of the piece, plan to extend the hold 
at casting temperature until the bubbles have burst and healed.  Firing schedules provided
are specific to the Paragon GL24AD kilns that we use in our factory Research & 
Education department. All kilns fire differently. You may need to adjust the firing 
schedule for your specific kiln and project.  After the entire firing cycle is complete, we 
recommend leaving the piece in the kiln at room temperature for at least a day before taking 
it out to divest it.


Cleaning the finished piece
Remove the piece from the kiln and disassemble the box mold. Remember to wear an 
approved mask while handling the fired fiber paper and investment materials. Watch 
out for any sharp points if the glass has clung to the side walls of the mold.
The investment can be removed from the glass with a variety of tools, such as dental 
instruments, wooden picks, nylon brushes, and wood carving tools. Wooden 
tools are ideal for carefully removing broad areas of investment, and metal tools should 
be used delicately to clean fine details. A nylon bristle brush and forced air are also 
great tools for cleaning areas of residual investment. Most of the investment should be removed 
from the glass before submerging it in or scrubbing it with water. While water can be 
used to rinse away residual investment, we have found that scrubbing the glass with 
vinegar and/or CLR* breaks down the investment material.  Remember that you can create
a very different effect if you decide to coldwork and/or polish your piece. The optical 
qualities can change substantially, especially with coldworking on the edges.

Detailed glass casting information

We found this detailed information on creating molds for glass casting on http://www.digitry.com/glasskitchen/5castcorn.html by Susan J. Longini and Mary Bayard White.  It has a lot of great information for any glass artist interested in learning glass casting!  

Finished corn, billet and frit

CAST CORN à la Cire Perdue

The Bay Area natural foods tradition prompted us to prepare corn on the cob glass multiples by casting rather than genetic modification. The cire perdue (lost wax) process involves making a negative mold of the corn, pouring a wax positive into it, investing the wax, melting the wax out and melting glass into the investment. The molds that offer the best detail for pouring over 4 waxes are often rubber molds with a plaster backing. They are time consuming and expensive to make, but worth it if one wants to make many multiple waxes. Silicon and dental alginate molds hold up for about four pours and provide a less costly and faster alternative, as in this situation. Two recipes for making the wax corn, and two mold recipes for casting the glass corn follow. Special thanks to Mitchell Gaudet for his casting/cooking wisdom.


Cire Perdue Corn Positive à la Silicon Mold

This recipe is inexpensive, durable, quick, and can produce approximately four decent waxes. The mold is temporary.

Ingredients and Equipment
One cob of corn with a hole drilled through stem and threaded with string
Razor blade and 20 hat pins
5 cups bees wax or Brown Victory wax, enough for four corns
Pot to melt wax in: double boiler, crock pot, preferably with temperature controller
pouring cup for wax
2 tubes GE Silicon Rubber I (not II) and tube dispenser
2 tablespoons Dawn liquid soap
4 cups water

 

Steps
1. Attach cob of corn so it can hang securely from hook or beam. Hang mold without touching anything.
2. Dissolve 2 TB Dawn liquid soap into bowl of water and squirt out entire tube of Silicon Rubber into bowl of water.
3. Thoroughly mix with hands, immediately pat onto the corn until evenly covered to 1/2" in depth. Mix up a second tube of silicon immediately and apply if silicon layer is not at least 1/2" thick. Use second tube of silicon if necessary to cover the corn to the right thickness.
4. Cure 24 hours. Some silicons need longer.
5. Use razor blade to cut down the side of the wax corn through silicon about 4" so the corn cob can be carefully pulled out of the mold.
6. Pin up sides of mold with hat pins placed in opposite directions.
7. Heat up wax in double boiler or crock pot. Do not allow it to boil. Make sure no water is in the wax.
8. Pour wax, (melted at 212°F or below) into corn mold. Pour out excess wax when wall is 3/4" thick.
9. When wax has cooled, remove from mold Wax Corn on the cob. Wait till wax is very firm on inside, at least four hours unless quite cool environment.
10. Remove from mold and pour another corn. Repeat until four corns are cast.

OR

Cire Perdue Corn Positive à la Alginate Mold

Wax Corn a la Alginate mold: very immediate, can cast organic material, will not irritate skin, more detail, very tear able mold, harder to handle, will shrink and distort in several days, needs refrigeration. Several types of alginate are easily available, but none are inexpensive materials: Dental Alginate, Dermagel, Hydrogel N.

Ingredients and Equipment
One cob of corn with a hole drilled through stem and threaded with string
Razor blade and 20 hat pins
5 cups bees wax or Brown Victory wax, enough for four corns
Pot to melt wax in: double boiler, crock pot, preferably with temperature controller
Pouring cup for wax
About 4 cups Dermagel or other preferred brand
Bowl to mix alginate
Water and measuring cup
Plexi tube hinged on side or mold made from plastic containers and duct tape

Steps
1. Attach cob of corn so it can hang securely from hook inside the plexi cylinder or plastic mold. Allow about 1 1/2" clearance on all sides.
2. Start wax heating.
3. Check volume, measure enough Dermagel in bowl to fill the volume and add water to creamy consistency. One part to 1-1/2 part water or the proportion listed in the alginate you are using. Alginate will stay lumpy.
4. Mix fast with hands and pour into mold. Let set about ten minutes.
5. Open mold and cut down the side of alginate just enough to pull out corn cob.
6. Pin up the side with hat pins and pour wax into corn mold. Pour excess wax out when wax wall is at least 3/4" thick.
7. Remove wax corn from alginate mold and pour as many as possible until mold breaks down.
8. Store Alginate mold in refrigerator, good way to cool wax.

Sources
-Hydrogel N Polytek, 610 559-8620
- Dermagel: Douglas and Sturgess, Inc. 1888-ART-STUF www.artstuf.com
-Victory Brown Wax www.Fremansupply.com

Measuring amount of glass needed for glass casting mold
Once the wax positive is made, and before putting any mold material on the wax corn, calculate the volume of the positive by submerging the wax in water jar, and calculating the volume of glass needed by water displacement. Record that volume for use in calculating the amount of glass needed to fill mold. If using frit, specific gravity of the displaced water can be used to calculate weight of glass to be used. Add 1/3 more glass if using flower pot drip method.

Glass types
Either solid glass or frits may be used. The tinted Bullseye transparent yellow is perfect for corn. A mixture of clear opaque and transparent frits will give a more mottled corn effect, and have less transparency.




Wax positive and starting to apply Mold Mix 6

CAST GLASS CORN MOLD RECIPES
Two glass casting molds: Mold Mix 6 and Plaster/silica/refractory mold

Mold Mix 6 glass corn mold with flower pot drip fill
using glass billets

Mold Mix 6 is a high alumina shell material used primarily for casting metal. It can be applied with little mess, is excellent for small solid shapes like corn, and gives the glass a shiny surface.

Ingredients and Equipment
Wax positive
Latex or vinyl gloves
OSHA approved mask
Hair spray
Food coloring
Wood board 4"x4"
Metal grid
Pan of water to catch wax:
Mold Mix 6 (Luminar) 2 cups in sealed airtight container
Second airtight container to put half of the MM6
Open mouth glass jar with 1cup water, for washing brush
Stiff brush 1/2 ", not nylon.
6 cups beach sand
Braun hand blender
Propane and blow torch
Kiln furniture
4" flower pot
6-7" flower pot
High temperature gloves
Bullseye Glass tinted billets: yellow, a little less than one half billet per corn

Steps
1. Touch up the wax corn positive so surface is exactly as desired and construct a 2" x 1" reservoir out of wax and attach to the stem. Calculate the amount of glass needed to fill the corn mold. If using Bullseye tinted billets, do this by replacing same volume of wax corn with volume of glass. Then add 1/3 more glass by volume to account for glass left in flower pot.
2. Attach the wax positive reservoir to a wooden board so it stands up and can be moved around easily. Very important to attach it securely so it will not break off in the mold making process, which takes 3-5 days. Spray with light mist of hair spray.
3. Whip up about 1 cup of the MM6 in a separate seal able container with Braun hand blender.
4. Start to paint onto the wax corn, being careful to apply thinnest layer possible, and let dry until hard. MM6 is
inherently lumpy, so just work with the lumps to create a smooth paper pulp like surface.
5. Continue applying layers of MM6 every day until 4-6 layers are applied. Total thickness will be no more than 1/2".
6. Each layer may be colored with a little food coloring to distinguish layers. Make sure the layers near the
bottom reservoir lip are even and at least 1/2" thick. Do not apply next layer until first is dry. Keep layers as
thin as possible
7. When mold is hard and dry after last coating, take mold off the wooden board and set on metal grid over a pan of water. Best to do outside with good ventilation. Victory wax will burn with sooty deposit.
8. Use large propane hand torch, the kind used in a hot shop, to start melting out the wax.
9. Slowly heat the bottom near the reservoir so the wax begins to melt. Do not start at the top of the mold because the wax will seep out through the MM6. As it is heated, the mold will turn black and sooty. Try to avoid setting the
wax on fire by holding the torch far away. Continue to heat from bottom up. Melting process may take up to
half hour.
10. Slowly move up the mold and melt out wax from bottom of mold near the opening. Beeswax melts out more easily and has fewer fumes than Victory Brown wax, however it is more brittle to work with and a little bit more of
a challenge to touch up.
11. When wax is completely melted out of mold, increase the heat and torch the mold until it is red hot and turns from black to white again. It will then feel like egg shell. Let cool. Hold up to a light and check for cracks. Patch with another layer of MM6 if necessary. It has not been necessary to reheat with the torch after patching.
12. Pour thin solution of Bullseye shelf primer into MM6 mold with quick motion, fill it up and pour out immediately.
Pre-fire mold to 600F if filling with frit for firing. If using flow pot drip method, the pre-heat is not necessary.
13. Prepare 4" flower pot large enough to hold the glass and use pliers to grouse out the hole in bottom to make sure glass can flow easily. Place glass in flower pot.
14. Place mold in large 6" flower pot and fill with sand so sand is around the entire mold to be filled
15. Build structure of kiln furniture (can slice up broken kiln shelves into 1" strips) so that flower pot is about 1" higher than mold and hole is directly above the hole in mold. If the reservoir is at least 2" diameter, there is plenty of room for the glass to flow down in a circular movement and fill the mold. Do not support the flower pot on the mold, make a scaffolding of kiln furniture.
16. Start firing. When mold has reached 1550F for one hour, check to see if glass has filled mold. If not, maintain 1550F temperature until filled. Spoon more glass into the hot flower pot while in the kiln if necessary. When glass has filled, bring down kiln quickly to annealing temperature. Pull hot empty flower pot when mold is filled, because, sometimes the stream of glass from the pot will cause cracking in glass as it cools.
17. Cool and wait 24 hours after removal from kiln. Break away mold off carefully. With shelf primer is applied to the inside of the mold, the glass usually comes off clean.

Sources
-Mold Mix 6 (formerly Luminar)
ZRCI
PO Box 489
Florida, NY 10921
845 651-2200 www.zrci.com
Temperature Controllers: Digitry Company, Inc. www.digitry.com
-www.bullseyeglass.com

Firing Schedule for both Mold Mix 6 and Plaster/Silica/Refractory Mold

step	Step Time	Temp °F
1	1 min	200
2	6 hr	200
3	4 hr	1000
4	2 hr	1000
5	2 hr	1550
6	3 hr	1550
7	1 min	1250
8	2 hr	1250
9	1 min	1000
a	1 hr	970
b	5 hr	920
c	1 hr	920
d	1 min	800
e	1 hr	800
f	5 hr 30 min	250

Plaster/silica/refractory mold with reservoir and frit firing

This is a type of mold that releases easily, is tough and has little cracking and flashing. Very soft dental plaster can be used for the first layer. It is harder to make than MM6 mold, but assures easy release and for more complicated shapes, is more applicable.

Ingredients and Equipment
Wax positive
Latex or vinyl gloves
OSHA approved mask
Hair spray
2 lb silica, at least 120 mesh, some finer
1 lb 30 minute casting plaster
Plastic bowl or bucket to mix
1 lb refractory cement: approx 60% alumina, any brand available.
Plastic wrap
Wooden board 5" x 5" approx.
Wall paper steamer
Pan with water to catch wax
Metal grid to hold mold while steaming
Aluminun foil
Bullseye Frits: #1 or #2 clear with no more than 10% opaque and transparent yellow powders mixed in when clear
glass is moist.
Bowl to mix frits and spoon or spatula
4 cups vinegar

Steps
1. Attach wax reservoir to wax corn so it is very stable. Very important part, because frit will be loaded into reservoir when kiln is at1550F.
2. Attach wax corn and reservoir to wooden board and spray with Hair spray
3. Mix 1 part plaster and 2 parts silica 40% to 60% and sift into 1-1/2 part water.
4. Paint on first layer with brush, or use hands.
5. Continue to cover wax with plaster/ silica mixture until 1" thick all around. Let set one hour.
6. Mix up refractory cement with water so forms ball when squeezed. Pat over plaster/silica until a 1/4" to 3/4" shell is
created. May need to hold refractory in place with tin foil or plastic wrap. Can put hair pins in wax in order to control even thickness of the walls of the mold.
7. Pull out any pins before the refractory drys.
8. Steam out all wax from mold. When top of the mold is hot, usually all wax is gone. Use aluminum foil to cover mold and direct steam.
9. Let dry three to four days.
10. Set up in kiln so easy to reach and fill when hot. Use kiln furniture.
11. If using frits, measure glass and fill mold and reservoir. Turn on kiln and fire.
12. When reaches 1550F for one hour, check to see if mold is filled. If not, maintain 1550F and use large stainless steel spoon to fill until mold is full.
13. Cool and do not break out for 24 hours.
14. Break outside mold off carefully. Be careful when chipping away outside layer. Inside layer should crumble away. Soak in vinegar, then clean with water.

Firing schedule: See Above

Kilns
Top loading kilns with side and top elements work. Ideally kiln will have elements on top, bottom, and sides.

We both use Digitry controllers, have used them for many years, and find them student user friendly and good for our purposes.

Pattern Bars

A pattern bar is a thick bundle of glass that has been fused together to form a solid mass. The size of pattern bars can vary, but most are one or two inches by about an inch and several inches long. When formed, these bars can be cut into slices with a glass saw, lapidary saw, or trim saw and then re-fused to make unique items.
Pattern bars are related to murrine, mosaic cane developed to its height in Italy and often formed using lampworking techniques. Millefiori ("thousand flowers") are the best known of these canes, which can be sliced and used in fusing projects. If you wish to make similar items using a kiln, the pattern bar methods described in this section will help you get the job done.

• Cold bundling

This technique, in which strips of glass or stringer are bundled together to form one large pattern bar, works well for simple forms. The glass bundle should be wrapped in fiber paper, then tied together with a high temperature wire (such as nichrome wire) and stood on end in the kiln. Fire to full fuse, then anneal and cool. Because of the thickness of the fused glass, care should be taken not to anneal or cool too quickly.
Stacks of glass strips may also be fused to form pattern bar strips. To maximize the evenness of the strips and minimize the likelihood of distortion during firing, the stacks should be supported by fiber paper, fiber board, and kiln furniture, as illustrated in the photo to the right. This layout allows you to form a large number of patterns bars at one time.

• Using a stainless steel

A alternative to bundling, this method of making pattern bars involves the use of a stainless steel mold to hold the glass strips. For best results line the mold with fiber paper, then arrange the strips inside, fire, anneal, and cool.
This approach has several advantages over simple bundling. First, unless carefully prepared the bundled strips have a tendency to deform or even topple over in the kiln. Second, using a mold allows you to use frit and other irregular shapes that can't easily be used when bundling. Finally, the small shape allows it to use space that would otherwise be wasted in a casting or full fuse firing.

• Using a plaster/silica mold

This technique, which is really a simplified version of kiln casting, involves using a plaster/silica mixture to form a mold for containing the glass to be fused together. Wax is the best substance to be used to form the mold, but other items can be used, including small wood strips.
The section on Kiln Casting (see advanced topics) discusses how to create the model and manufacture the mold. The spaces created by this technique can be filled with strips of glass or frit, then fired to full fuse and annealed and cooled.
When cool, carefully break through the plaster/silica mold. Slice the pattern bars into cross-sections and re-fuse to form a new object.
One advantage of this technique is that round items can easily be made by selecting a round shape to form the hole. Round slices are particularly fascinating to fuse together because they deform and form hexagrams when fused together side by side.

• Using Styrofoam

This final technique builds on the plaster/silica method by using Styrofoam to form more complicated shapes. Start with a block of Styrofoam the size and shape of the pattern bar you desire. Then cut the Styrofoam lengthwise using a hot wire Styrofoam cutter.
Take the two (or more) pieces cut from the Styrofoam and use them as the models to be encased in the plaster/silica mixture. Although they fit together, mold them separately. If you burn out the Styrofoam, you'll be left with a form the shape of the Styrofoam model.
There are several ways to get rid of the Styrofoam. One method is to pour acetone onto the Styrofoam.  This will dissolve it, but care must be taken when handling acetone.  Another procedure is to use a small propane torch to burn out the Styrofoam. You can also use a well-vented kiln (fire to about 1200 F). In either case, avoid inhaling the fumes and make certain you have adequate ventilation.
Once your Styrofoam has been removed, you're ready to fill the remaining form with glass. You can use strips or frit (as in the other types of pattern bars), or you can simply fill each form with a different color of glass.
When you're ready, fire to 1500 to 1550 F, soak until the glass settles (you may want to top up the form), then anneal and cool.
Once the forms are cool, carefully break away the plaster/silica mixture. Slice the bars with your glass saw and fit the shapes together. Re-fuse this assemblage to form a uniquely patterned warm glass object.

This very helpful information was found in http://www.warmglass.com/pattern_bars.htm  an excellent site for art glass information.  We highly recommend this site to all glass artists!

So now that you know how to make pattern bars, perhaps you are wondering what you can do with them.  Cut into small pieces and used in jewelry, such as pendants and earrings, you can create beautifully stunning one of a kind pieces.  A lot of glass artists also use slices to create boarders on plates as well.  Actually the possibilities are endless, it's just up to your imagination!