REUSABLE MOLDS FOR CASTING

First some background: There is a Many of these molds have built-in force called “surface tension.” Sur- slumpers to add “life” to the final face tension causes any liquid to piece. A schedule is also “ up.” (An everyday example included. is the way rain drops bead up on a car’s hood.) If glass is hot enough, COE 96 Firing Schedule it will bead up, pull away from the Seg 1!300˚F/hour to 1350- mold’s edges, and thicken. 1375˚F, Hold 10 minutes Here are the secrets to thin cast- Seg 2!AFAP (As Fast As Possi - ings with fine details: ble) to 960˚F no vent- ing. Hold 30 minutes Tips for Thin Castings ✓Use the Thin Fire fill weighs Seg 3!Off, cool kiln, no vent - As people become more experi- that can be found in “Fill enced with our molds, they start ing Weights at a Glance.” This wanting thinner and more deli- cate castings. Let us pass along lower fill weight is usually about these hints and advice to achieve two-thirds to half the fill weight COE 90 Firing Schedule that goal. shown on the packaging. One can add more or less frit to cus- Seg 1!300˚F/hour to 1375- nnn tomize the casting size. 1400˚F, Hold 10 minutes Seg 2!AFAP (As Fast As Pos - Use fine frit. It requires less ✓ sible) to 960˚F no vent- Many of our newer designs look heat work to conform the ing. Hold 30 minutes best when cast very thin. These smaller particles to the mold’s Seg 3! Off, cool kiln, no vent - designs included: surface. ing • All our leaves, e.g. Oak ✓Use lower temperatures. These Leaves and Acorns, Tropical accompanying schedules are Leaves, Assorted Small designed to barely fuse the frit Slumping Schedule Leaves, and Leaves (3) particles together, but before Seg 1! 300˚F/hour to 1225- All our flowers, e.g. Dog- the glass becomes fluid. At the • 1250˚F, Hold 5 minutes wood, Rose, Blossoms, Small low end of the temperature Seg 2! AFAP (As Fast As Pos - Mixed Blossoms 1 and 2, range, the piece will have a sible) to 960˚F no vent- and Lotus matte, “sugar fire” finish. At the high end; a glass-like finish. ing. Hold 30 minutes • Honey Bees, Small Dragon- Seg 3! Off, cool kiln, no vent - flies, Small Butterflies Every kiln is different and firing ing schedules can be affected by glass • Lily Pad and Frog thickness, number of pieces in the firing, number of kiln shelves, A complete list of designs to which whether the kiln has top and/or this applies is in “Fill Weights at a side elements, and even glass color. Availability Glance.” This document is located Colour de Verre molds are However, here are two firing in Colour de Verre’s Project Ideas available at fine glass retailers schedules – one for COE 90 and section. and many online merchants one for COE 96 – that can serve including our online store, Just how do you go about getting a as starting points for thin, fully www.colourdeverre.com. thin, light weight casting? fused, finely detailed castings. May 2009 REUSABLE MOLDS FOR

Create the Ginkgo Leaves If you prefer, you can use boron Before each firing, clean your nitride aerosol primer. (We used molds with a stiff nylon brush to this for our project) We recom- remove any old kiln wash. (This mend ZYP exclusively. You can can be skipped if the molds are read more about this in Advanced brand new.) Priming with Boron Nitride Aerosol which can be found in our web- site’s Project Ideas section. The ginkgo leaves are cast from a combination of fine Moss Green and fine Yellow frit. To create vis- Ginkgo Plate ual interest, three different frit This low, shallow plate is a combinations are used. great accent for a dining room table. nnn Give each mold cavity four thin, Given the finished piece, one even coats of Hotline Primo might think of this as too complex Primer. Each gingko mold has six a project for a beginner. Actually, mold cavities built in, but since this project can be completed by there are three on each side, only people new to glass casting. The three ginkgo leaves can be cast per trick is to approach the project as firing. It is not necessary to prime mold cavities that won’t be filled. four “mini projects”: Combination #1: Hotline Primo™ primer is the 30% fine Moss Green • Create a collection of ginkgo castings. Make more than you only conventional primer we rec- 70% fine Yellow ommend because it doesn’t ob- expect to use so that you can ex- Combination #2: periment with various layouts. scure the mold’s fine detail and is easy to remove after firing. Use a 40% fine Moss Green 60% fine Yellow • Fuse two pieces of sheet glass soft brush to apply the primer and together to create the panel. a hair dryer to completely dry Combination #3: each coat before applying the next. 50% fine Moss Green • Tack the cast leaves to the panel. The mold should be completely 50% fine Yellow • Slump the panel using a shallow dry before filling. form.

Tools Supplies Availability ✓Ginkgo Leaves mold ✓Hotline Primo Primer or ZYP Colour de Verre molds are ✓Small and Large artist’s brush ✓Fine Moss Green and Yellow frit available at fine glass retailers ✓Small containers for mixing frit ✓Moss Green Frit and Stringer on and many online merchants Digital scale Clear; Clear and White Streaky including our online store, ✓ www.colourdeverre.com. ✓Assorted kitchen measuring sheet glass spoons ✓Powder Black frit. REUSABLE MOLDS FOR GLASS CASTING

Combine the two frit colors in lid- piece according to the Tack Fuse ded containers and shake to com- Schedule. bine. (Empty frit jars work per- fectly.) Whenever mixing frits, it is highly advisable to wear a dust mask. As mentioned above, each mold has six casting cavities, three on each side. The fill weights for Side A, the side with the “Ginkgo Leaves” text are 9, 9, and 9 grams. per. Stack the Moss Green frit and the fill weights for Side B, the side stringer glass on top of the white with the copyright text, are 15, 7, and clear streaky glass. Place the Slumping the Panel and 14. stack in the kiln and fire according Place the panel into a primed to the Sheet Schedule slump mold. Slowly fire the piece To accentuate the subtle veining, below. sprinkle ¼ to ½ gram (a pinch) of according to the Slumping Sched- black frit into each cavity. Hold the Attaching the Elements ule. It is important not to rush the mold in place with one hand and Remove the fused panel from the firing as there is quite a bit of use the other to tap the mold. This kiln and place on the workbench. thickness variation. will cause the black powder to set- Create a pleasing arrangement of Variations ting into the mold’s shallow groves. ginkgo leaves on the fused panel. There are many combinations of Using the fill weights mentioned Use small dabs of white glue to sheet glass and frit color for which above, evenly fill the ginkgo leaves. temporarily hold the components this technique produces beautiful Lightly tap the mold to level the in place. When dry, move the results. One we found particularly frit and transfer the mold to the panel to a kiln shelf that has been pleasing was a 14” round disk cre- kiln. Fire the molds according the protected with primer or a piece of ated with Black Streamer Bits on Component Casting Schedule. ThinFire shelf paper. Fire the (See “Tips for Thin Casting” in the project section of Colour de Verre’s website.) Component Casting Schedule* Segment Ramp Temperature Hold If the castings “ball up” decrease 1 300ºF/165ºC 1340-1360ºF/725-735ºC 30 minutes either the hold time or target tem- 2 AFAP 960ºF/515ºC 30 minutes. Off perature. Given the differences * Schedule for COE 96. For COE 90, increase casting temperature by 25ºF/15ºC. AFAP means between individual kilns, it may “As Fast As Possible”, no venting. take one or two test firings to get perfect results in your particular Sheet Glass Fusing Schedule* kiln. Segment Ramp Temperature Hold 1 250ºF/135ºC 1200ºF/650ºC 30 minutes Creating the Panel 2 250ºF/135ºC 1410-1420ºF/765-770ºC 10 minutes Cut a 10x10” (25x25cm) square from each piece of sheet glass. 3 AFAP 960ºF/515ºC 60 minutes Protect the kiln shelf with primer 4 100ºF/60ºC 700ºF/370ºC Off. No venting or a piece of ThinFire™ shelf pa- * Schedule for COE 96. For COE 90, increase casting temperature by 25ºF/15ºC. AFAP means “As Fast As Possible”, no venting. REUSABLE MOLDS FOR GLASS CASTING

Clear sheet backed by an off-white Tack Fuse Schedule* or Almond sheet. Segment Ramp Temperature Hold 1 200ºF/120ºC 1200ºF/650ºC 30 minutes 2 200ºF/120ºC 1260-1275ºF/680-690ºC 5 minutes 3 AFAP 960ºF/515ºC 60 minutes 4 50ºF/30ºC 800ºF/425ºC None 5 100ºF/60ºC 600ºF/315ºC Off. No venting * Schedule for COE 96. For COE 90, increase casting temperature by 25ºF/15ºC. AFAP means “As Fast As Possible”, no venting. Slumping Schedule* Segment Ramp Temperature Hold Ginkgo leaves were created using 1 100ºF/60ºC 200ºF/95ºC 15 minutes the following frit combinations: 2 100ºF/60ºC 400ºF/205ºC 10 minutes Combination #1: 3 150ºF/85ºC 1250ºF/675ºC 10-20 minutes 30% fine Medium Amber 3 AFAP 960ºF/515ºC 60 minutes 70% fine Pale Amber 4 50ºF/30ºC 800ºF/425ºC None Combination #2: 5 100ºF/60ºC 600ºF/315ºC Off. No venting * Schedule for COE 96. For COE 90, increase casting temperature by 25ºF/15ºC. AFAP means 40% fine Medium Amber “As Fast As Possible”, no venting. 60% fine Pale Amber The tack fused disk was shaped Combination #3: using a shallow bowl slump form. 50% fine Medium Amber 50% fine Pale Amber As before, a little black powder was sprinkled into the mold to ac- centuate the detail.

A “random” pattern was collaged and tack fused into place. REUSABLE MOLDS FOR GLASS CASTING

stiff brush to stir the compacted piece still doesn’t fall out, the mold particles off the bottom of the probably wasn’t properly primed. container and back into solution. Occasionally, a few glass It is not necessary to pre-fire the spurs might be on edges of mold as long as the primer is dry. 7 the finished pieces. These After firing the mold, use are easily removed with a wet any nylon kitchen brush or diamond block or grinder. Follow- 2 a toothbrush to remove all ing hint #4 will minimize these. traces of the primer from the Butterflies, dragonflies, mold. We strongly recommend flowers, and leaves can be wearing a dusk mask. 8 Tricks of the Trade given more life with a sec- We want our customers to have Always follow the firing ond, slump firing. Some of our a great experience and wonder- schedule recommended on designs have a specially designed ful outcomes with our molds. 3 our website and packag- slumping surface on the reverse Let us pass along these hints ing. Colour de Verre molds are side. and advice. made from a specialized ceramic A “sugar fire” yields won- nnn material. Like glass, this ceramic derful results with Colour will crack or shatter if it is heated 9 de Verre snowflakes. Fill or cooled too fast. the mold to half of the recom- U s e H o t l i n e P r i m o Finished pieces will have mended fill weight with fine frit. 1 Primer. We tested many much smoother edges if Fire to a “partial fuse” – about kiln washes and primers 4 you use a small brush to 1300°F (705°C). This technique from a number manufactures. move the frit away from the top can be used with any of our Only Hotline Primo Primer of- edge of the mold. This “trough” molds. fered us the three properties that only has to be 1/8-inch wide and Don’t be afraid to experi- we required: thin, even coats that deep. don’t obscure the design; consis- 10 ment. Add CMC solution tent release; and fired primer can Use only crushed to your glass powders to easily be removed with a stiff 5 or frits in Colour de Verre make a pate de verre paste. Mixed brush. molds. The molds are not crush dichroic with your frits. Tack designed for Pyrex glass, float fuse finished pieces to slumped Mix the powder with water ac- glass, or crushed bottles. We don’t plates and platters. Mix shredded cording to the label instructions. recommend firing Colour de Verre copper, , or gold foil into your Apply four to five thin coats to the molds above 1500°F (815°C). At frits. Embed smaller forms inside mold’s inside surface. Let each higher temperatures, the primer of larger, clear forms. The possi- coat dry before applying the next. will start to fuse and becomes bilities are endless. A hair dryer can be used to accel- more difficult to remove. erate the drying between coats. Keep the primer well stirred. The If the finished piece Availability primer’s fine particles – the active 6 doesn’t fall out of the Colour de Verre molds are components – settle out of the mold, don’t panic. Turn available at fine glass retailers mixture rapidly. If the primer set- mold face-down and tap it against and many online merchants tles, the particles will start to cake a hard surface cushioned with sev- including our online store, on the container’s bottom. Use a eral layers of newsprint. If the www.colourdeverre.com.