FUSING / SLUMPING
MOLD MAKING
Barb Grollo: I thought I'd pass on the info I got from Pat today about how she does the mold. The product that I loosely referred to as "mold material" is actually called "Moist Pack". It is fiberblanket with fiber mold hardener already added, or you can purchase fiberblanket & fiber mold hardener and mix your own. She said the Moist Pack is easier, and to use 1/2" Moist Pack. Cut a piece which is a few inches larger in all directions than the area in which you are slumping pieces to fit. Press the material inside the area you're planning to slump, smoothing as much as possible. It should be left in place to air dry for 2 to 3 days, enough to harden for handling. Then fire it in the kiln to at least 50 degrees over the temperature you would need for slumping, so approximately 1300 to 1350 degrees, as the glass should slump at about 1250 degrees. When it's cooled, coat the mold with kiln wash (sometimes called glass separator) and give it 3 or 4 coats. She said there was no need to recoat it between firings as that seemed to make the material break down quicker. If doing the dragonfly (for a Tiffany Dragonfly lamp), cut the wings and position on the mold at the angle they would be on the Odyssey mold and fire till slumped. (different glass slumps between 1200 and 1250 degrees). She cautioned that you should only fire Moist Pack in a well-ventilated area as it contains ether. And never fire anywhere near birds, as it could be fatal to feathered friends. I think the product is readily available, as it's listed in her Big Book, and she gets hers from Ed Hoys.
Walt Boepple: Joan Luckhurst showed her method of making a mold of your lamp mold for the purpose of making a slumping mold to slump glass in the kiln. Joan went to a local pharmacy and got a small box of gauze that is filled with plaster of paris in the webbing. You place the piece of gauze in water and remove it and place over your mold. You do this similar to the discussion we had on the skins not long ago. After it hardens you have a perfec mold of your mold. You can now fill your mold with the mold mix you use for making your slumping mold. This way you don't have to put the mold mix on your mold.
ON RINGDROP VASES:
Sue Knowles: Re: Fibreboard 1 Inch is more than sufficient, I only use 12mm thick which is about 1/2 inch thick.....it is stiff and you can cut a circle out of the centre and use it on kiln posts to do a ringdrop vase quite easily..... Kao wool is the soft version,fibre blanket is the type of "stuff" that you would line the walls and lid of a fibre kiln not a brick kiln, moist pack is the wet version that you would form slumping shapes from like a bowl, fibre paper is the thin version that you would line a kiln shelf instead of kiln washing.....and yes....please wear a mask for the prevention of silicosis (sp) and gloves in case of skin irritation....or wash your hands immediately. You would kiln wash (see next section on Kiln Wash) or line with kiln fibre paper the bottom shelf to avoid your ringdrop vase from sticking to the floor of the kiln. Do not forget that if you do any designs on your vase to make sure of the C.O.E. and make sure that all your layers of glass add up to about 10 mm thick cause it will stretch and become thinner when it drops.
Sue Knowles: Regidiser, I do not find it " really " necessary, but it would lengthen the life of the fibreboard if you intend to make a dozen ring drops, I have found the ...rigidising....products that are available to me, very messy, and not seeing your product would worry about the glass picking up some of the prooduct in firing on the underside of the vase. But it does make the board stronger as firing tends to soften and render the board useless quickly.
ON KILN WASH:
Sue Knowles: Kiln wash....is only a separator....and it also is picked up by the soft glass...and looks awful if this happens...it also starts to crack or craze all over the fibreboard after a couple of firings...it does nothing to strengthen the fibreboard..... the fibreboard will also be " picked up" but once the vase is cooled and removed from the kiln, you can wash it and all the fibres will come off the glass easily.
Sue Knowles: I make my own kiln wash , a mix of alumina hydrate and china clay (equal parts) say five big spoons of each in a large coffee jar topped up with water ( becomes quite thin) well shaken and brushed on first one way then the next in light even strokes several layers.....works like a charm and it is the cheapest that we can do.
Nicole O'Neill: I took a fusing workshop a few years and paid close attention to the process of placing kilnwash on the kiln shelf. I haven't done a lot of fusing, but have gotten a relatively smooth surface using the following directions. The trick was to use a very dilute solution and apply it with a wide (5") hake brush. Make a solution (suspension?) of 1 part powder (kaolin and alumina hydrate (1:1), or commercial kiln wash) to 5 parts water. Brush the solution on in layers, in different directions, until you cannot see the shelf. Allow the shelf to dry (use the kiln, vented a little, to speed up the drying). It will be smooth, with no brush marks. Arrow Springs sells bead supplies and has a nice catalog and fusing supplies. Their # is (916)677-9482.
ON FUSING IRIDESCENT GLASS:
Stephanie Braman: Here's is a trick to keeping the iridescent coating when you fuse which also gives the finished piece a deeper look. It requires 2 pieces of glass -- one iridized and one cathedral. Cut out your pattern piece from each of the glasses, then lay one atop the other with the iridized coating facing the cathedral glass and full fuse. It's best to fuse at a lower temperature over a longer period of time to reduce the chances of the coating burning off. What happens is the coating is trapped in between the glasses and if you use a textured iridescent, the iridized pattern is very 3D-ish looking.