tag:blogger.com,1999:blog-65358894390702443252026-10-18T23:12:15.867+01:00Information on stained glass, fusing, kilnforming and glass working Stephen Richardhttp://www.blogger.com/profile/17854964450984329333noreply@blogger.comBlogger1340125tag:blogger.com,1999:blog-6535889439070244325.post-4201007492456143502026-10-14T07:00:00.043+01:002026-10-14T07:00:00.125+01:00

 How big can a square be for a drape former? The diagonal of the square for a former can not be more than twice the height of the former plus the base diameter. Of course it is better to be slightly smaller to allow for the glass stretching during the drape. But twice the height plus the base diameter is the maximum. An example. If the former base is 2 and the height is 7, the

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Putting slump and drape moulds on kiln posts is not necessary.  If you think you need air circulation under the mould, pieces of thick fibre paper are all that is needed. The widely accepted notion that all moulds need to be elevated from the shelf is not backed up by evidence.  There is a lot of anecdotal discussion which supports the idea that it is necessary, though.  The idea

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Does annealing stress in one firing cause breaks in the next firing? Stress does not cumulatively build up from one firing to the next. Once the glass has achieved the strain point temperature, the relief of stress begins and is complete by the softening point (usually the slump temperature). So why does the glass sometimes break on the second firing? Picture credit:  Emma Lee There

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Is there a way to find out if some stained glass is compatible with fusing? Yes, there is a way to test for compatibility. This strip test is the one I recommend. It is simple, repeatable and provides a reference for future use if labelled and stored carefully. Determining the Coefficient of Expansion (CoE) is a testing laboratory process, not something we can do at studio level. But

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Can glass wreaths be made from bottles? Last autumn a small group within the cooperative Jangling Space decided to see if we could make strip construction glass wreaths for Christmas.  This developed out of a collaborative project with Christopher Jeffree on whether bottle glass could be made to fit together at various sizes of frit. Testing for compatibility of glass at frit levels It was

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How to avoid prickles when damming glass? In using dams sharp needle points on the finished piece are common. This is a time when CoE has a practical effect.  The glass is expanding all the way to the top temperature. During this expansion upwards (it’s linear expansion is constricted by the dams), it takes up all the texture of the things it touches. When the glass begins to cool,

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CoE does not determine compatibility. Of course Coefficient of Expansion (CoE) increases the chance of compatibility, but when it is understood that it is CoE that is manipulated to give an equal but opposite force to the viscosity, you realise that CoE is a variable measurement of compatibility rather than a constant. The formulation for each colour of glass has to have a different rate of

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 Picture credits: Heidi Woj I”m assuming this was an anneal problem. All four corners broke/cracked. Steps: full fuse 2 layers of Tekta with 2mm leaves. Then contour-fused on the flower centers and petals (1-2 layers). [A total of 4 layers at the thickest] Finally, slumped onto GM97 tray mold. All was well until a couple days later. Thought I used very conservative schedules, but maybe

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  The description The objective is a sculpture 50mm x 50mm x 90mm (2” x 2” x 3.5”) composed of two layer slabs to make it 90mm high. The objective is to fuse the whole without distortion or dams. Assumption: My presumption is that the piece will be fired on its side rather than standing to full height in the kiln. Proposition: I propose that a sharp tack or sinter firing can achieve this

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 image credit: Olympic kilns Is it acceptable to have kilns on wheels? A number of people have small studio spaces and do not have their kiln in constant use. They sometimes move their kiln against the wall or under a bench when not in use. This is possible when the stand is on wheels, otherwise they generally are to heavy to without them. This gives more space in the studio to move

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A light and uneven distribution of frit that provides a pleasing image.image credit: Donna Brown It is often difficult to get an even distribution of frit across a background with already placed glass. It is possible to lay down a ground of frit and build the objects (in this case bees) over the frit. It is easiest to lay down an even layer of frit with no interruptions in surface levels.

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Description A frit stretch in the flattening developed two internal cracks at 4:00 and 8:00 going through colours (but not felt on top or bottom). The flattening was to reduce the centre thickness from about 8m, to be nearer the 6mm of the edges. It was fired in a side element kiln. The maker does not know if there is stress beyond the cracks. The question is about firing again to

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DreaminColoursArt How can veiling be reduced in heart casting moulds? These ways of avoiding or reducing the evidence of the cullet pieces laid into a casting mould rely on analogies with other methods of glass flow. A reservoir such as a small ceramic flower pot can be set above the mould to allow the melted glass to flow through the hole into the mould below. This removes all possibility of

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Is any glue required to stabilise glass pieces in kilnforming? If so, the amount, placing and type are important. The more glue you use, the more likely glass pieces are to move in the firing. Details here. Glue, whether dry or wet will boil with rapid rates. Most glues have boiling points between112°C and 270°C (230°F and 520°F), although super glue has a boiling point of only about 55°C (130

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Despite not opening the kiln until it was 120 degrees, a ¾" crack formed in the middle of a 15" x 15" flat fused 1/4” slumped platter, fused, then slumped. The bottom layer was four squares, topped by a single layer of Tekta. How can I avoid crack at the meeting of the squares? The fuse schedule was 300°F to 1110°F, 30’ 200°F to 1240°F, 60’ 600°F to 1475°F, 17’ 9999 to 900°

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Recommendations for a transparent sky blue apart from sky blue for a drop out so I need high saturation? Image credit: The Glass Hub Keep in mind that the colours wash out more at the shoulder of a drop out as it thins. To obtain a more even colour throughout the length of the drop the colour should graduate from the most dense at the shoulder to paler at the centre of the drop. One way

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Why do schedules vary so widely?I frequently observe strange annealing schedules promoted on the internet. These include: extremely long anneal times with rapid cools risking thermal shock. single slow cool rates, using more time and electricity than necessary to 371°C/700°F.  There are better cool arrangements that fit the needs of cooling glass. to room temperature.&

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Credit: Creative Glass GuildCan stringers be stabilised without glue?To stabilise a single or multiple stringers a few grains of powder are all that is required to move from the workbench to the kiln. Such small amounts of powder will not show up even at low temperature tack fusing.  This method will avoid using glue to keep any light weight item in place - frit, shards, small round pieces,

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How can sand pictures be produced in glass?This process provides flowing, abstract images that can be used as autonomous pieces or formed into other objects, such as free drops, bowls, cut for jewellery or into pattern bars.  The appearance provided is unique to this combination of using frit and pressing.In principle, this process is the same as creating sand pictures.  The

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What would happen if I tried ... in kilnforming? A lot of discussion on the internet seems to be a search for certainty in both stained glass and kilnforming. It seems to involve a search for rules in assembling work, or the right way to do a process. The fact is, there always are multiple ways to do a kilnforming operation and still get the same result. Never/Always statements are inevitably

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Loctite Glass Glue This is best for small craft items, adhering glass to glass and glass to metal. It is a cyanoacrylate glue. Suitable for light items. Once cured it is waterproof, transparent, and rigid. It is said to be dishwater proof, but will not withstand boiling water. No clamping of the pieces is necessary, but the joined object must be left undisturbed for 24 hours.

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 Vermiculite moulds have versatile applications as custom moulds both for draping and slumping. With care, they have a long life. They are relatively light for their size and strength. As the vermiculite is an insulator it does not store heat, making it useful for large moulds without the requirement for long cooling times.  The relatively low cost makes large moulds more affordable.It

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What can I make custom kilnforming moulds from?There are a wide variety of moulds available to purchase, but sometimes they are too expensive, or a special, distinctive form is wanted and needed.  There a number of ways to make a custom mould with a variety of materials. Fibre Paper (including SilkeMat) These are the most flexible in terms of shape and ease of use.  Most fibre papers

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 The advantage of plaster of Paris bandages to create a body cast are:· its light weight,· rapid setting characteristics,· the degree of detail picked up, and· rigidity.Its disadvantages are· its easy deformation while wet,· its fragility when dry, and· it is a messy procedure.The advantages over other methods of taking a cast from life are such that this is an almost ideal casting

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Credit: The Pottery WheelThere will be differences when firing on the floor of a kiln - the two important ones are working temperature and annealing. Differential temperatures  When firing on the floor of the kiln, expect the effective temperature to be a little lower than when on an elevated shelf. The temperature is always lower at the floor of the kiln and hotter higher in the kiln.

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