Approaching a Gallery

Images of WorkMake sure that you have good quality images taken of your work (35mm transparencies, digital images for CDs or email), after all, you will be competing with practitioners that have been in business for years and are firmly established as leading national and international designers. Sending poor images/presentations reflects very badly on your approach and your work.

Invest in a professional portfolio filled to the brim with beautifully laid out colour photography on a black background. Don’t walk into the gallery with a handful of snapshots.

Sending Biography and VisualsSend general descriptive information about yourself and your work to the gallery first. Then follow this up with a telephone call. Find out the contact name you need for the relevant department within the gallery. If you send something with no contact name your presentation can sit in a pending tray for months! Contact as many galleries as you can handle, rather than waiting for a reply from the first one on your list.

Research and Make Appointments
Don’t just turn up at a gallery with your work. Galleries plan their exhibition schedule at least two years in advance. They are busy most days with artists and dealing with clients so it is always best to make an appointment first.

Pop in regularly to your local galleries, or research on the internet, to get an idea of the kind of designers they display, and the style and quality of work on show.

Keep in TouchContemporary galleries are always looking for new original designers for their exhibition programme, so update the gallery regularly by sending emails, transparencies and CD (with images).

It is especially important that the gallery can see how serious you are about your work, how it develops in style and that you are still exhibiting and producing work 2-5 years later. Make sure your work is unique and difficult to duplicate. Keep your own designs and patterns dated and own the copyright to them.

Don’t give up. There's someone out there who will like your work. When you find gallery owners who are crazy about your work, stick with them.

When you have an offer of a show
Watch the papers for announcements of other openings at the gallery to see how well each opening is advertised. Ask around the arts community to see how well known the gallery and its owner are.

Check on the gallery/artist percentage agreement when calling each gallery. Your price to the public must be calculated based on this. Charge what the work is worth!

Check around with other artists represented by the gallery, asking them about promptness of payment by the gallery.

Be businesslike in all dealings.Prepare a contract, if the gallery does not have one, to cover mutual expectations. It should include who does what, e.g., mounting of the work, invitations to the opening, opening night, payment terms, artist’s residual and resale rights, etc.

Don’t be a pain to the gallery owner. Don’t pester. If you have to be anxious about the show, do it privately.

Enjoy the opening night!

Over Annealing

Sometimes the statement is made that you can never over anneal.  This statement is true only under certain circumstances. 

Annealing

The statement is also dependent on the understanding of what anneal means.  Annealing is the process of stabilising the temperature, ensuring the piece is at the same temperature throughout, and then gradually cooling the piece to avoid heat shock.  This is to point out that annealing is both the soak and the slow cool.

Long Soaks

Long soaks at the annealing stabilisation temperature can be injurious to your piece if the temperature in your kiln is not even.  This can mean that one or more parts of your piece are at different temperatures. This sets up stress within it.

Placing

You can reduce the possibility of stress by placing the piece at the centre of the kiln or avoid placing the piece in the cool spots of the kiln. 

Cool Rates

Another method of avoiding locking in the stress to the piece is to reduce the cooling rate to less than normal.  This will reduce the temperature differential within the piece.

Mass Being Cooled

In all this you need to remember that the anneal cool rate is relative to the mass of material to be cooled.  Therefore, a thick piece needs a slower annealing cool than a thin one.

But it is not just the thickness of the glass to be cooled.  You need to think about the mass of the kiln shelf or mould that supports the glass.  An example is that glass on a ceramic shelf needs slower cooling than one on a fibre board shelf, because the mass of the shelf needs to be taken into account as well as the glass. Connected to this is whether the shelf is on the floor - slower cooling - or supported on posts, allowing air to circulate under the shelf.

Fibre board moulds

A publication on moulds from fibre boards is available from Stained Glass Supplies. This gives much more detail than this note can.  However, the basics are outlined here.

Commonly available refractory boards are:

·         Calcium silicate

·         Standard fibre boards

·         Armstrong ceiling tiles

They can be used bare (except Armstrong ceiling tiles) or hardened.

A question that will arise is whether to harden or not.  This depends on the durability you require.  A board that is not hardened does not require kiln wash when fired.  However, as it is soft it is easy to break.  A hardened fibre board mould always requires kiln wash or another separator.  It does become durable and almost rings when tapped once it is hardened and cured.  If the shape needs to be preserved for further use, hardening is advisable.

Working methods

Usually hand tools are all that are required to get the results required.

Safety

Do any work on refractory boards outdoors if possible, and with a respirator.  If you must do it indoors, have good ventilation, wear a respirator, and clean up with damp sponges or other absorbent material to avoid putting the dust back into the air.

Do you need to pre-fire fibre moulds?

Moulds that are small or thin do not erequire firing before using.  Thick and large fibre moulds do need to have the binders burned out before use to avoid carbon marks on the glass.

Advice on Commissioning Craft

This is an outline of information you can give to a potential client to help them with the process of commissioning.

If you have always imagined owning something unique and original, or like to be distinctive and stylish and can’t find what you are looking for on the high street, then commissioning could be the way forward.

If you are nervous about taking the next step and uncertain what is involved, these are the key stages.
Step 1: What do you want?
Step 2: Research by looking at ideas and images that suit your imagination. Note who is working in that kind of style.
Step 3: Write a brief of what you have discovered and then discuss your ideas with the artist you have identified.
Step 4: Discuss the budget and get a written quotation.
Step 5: Agree on the time frame for progress and delivery updates. There are sometimes difficulties in making unique items.
Step 6: Communicate regularly with each other.

Remember, because the process is about communication, there is the potential for misunderstandings and differing expectations by the commissioner and maker. Make sure you have thought the process through before proceeding and ensure all aspects are clarified in writing before you begin - including the quotation, payment schedule, time frame, etc.

And finally…… Enjoy it

The opportunity to commission a piece is an exciting experience and can be rewarding to both you and the maker. As long as you are prepared, and keep communicating with each other, you will become the owner of a unique and special piece of work which will bring hours of pleasure and will be the envy of your friends. 



The full information can be downloaded from craftscotland

Polishing Brushes

The polishing brush should have moderately soft bristles. A long bristled shoe polishing brush can be used, although one that is a little stiffer does the job more quickly.

A shoe polishing brush

It is important to keep these brushes free of hardened cement, as a brush containing pieces of hardened cement will scratch the leads rather than darken them. As soon as the polishing is finished, inspect the brush for little balls of cement. Rubbing the brush against a clean rough surface will clean it while the cement is “wet”. Also running the brush at an angle on the sharp edge of your work bench will clear some of the cement adhering to the bristles.

A polishing brush with slightly stiffer bristles

If the cement hardens, you can clean the brush by crushing the hard balls of cement with a pair of pliers. Or you can just get a new shoe polishing brush.

Drawing an Oval

Need to draw an oval for a panel? Here's how:

• Set out the long axis horizontally.
• Set out the short axis at the half way point of the long axis at right angles to the horizontal.
• Measure half the short axis on each side of the long, horizontal axis.
• Calculate half the measurement of the longest line. In this example the long line is 340mm and the short axis is 200mm long.  
• Half the long axis is 170mm.
• Use that as a diagonal measurement from the end of the vertical axis. 

• Measuring from the end of the shortest line, mark off this amount on the longest line, right and left. You can use a ruler or compass set to the correct length, both will work.

• Insert a pin at both these points.

• Place a piece of thread, string - or in this case a quick release tie - round one pin. Tie a knot in the thread at the far end of the longest line.

• Put a pencil inside the loop. Pull the thread taut and begin to draw the oval.  Keep the tension even throughout the drawing to avoid a lopsided oval.

For a leaded panel, the space occupied by the lead came will need to be accounted for in the measuring of the dimensions.

This is a simple method that does not require much in the way of tools, but its accuracy is a result of the degree of attention to details.

Grinding and Polishing - Grits

Grinding and polishing grits and their effects

60 grit belts and disks provide a very aggressive grinding action. This grit takes large amounts of glass away very quickly. It makes shells and takes chips out of the glass with anything greater than light pressure. You need to create a small arris to avoid the shelling before grinding the face.  The metric size is 0.2337mm.

80 grit belts and disks provide a slightly less aggressive grind. But you must push lightly until you get the shape you want. On a new belt this is a remarkably fast process. Eighty grit belts can also take chips out of the glass, so be careful. Again an arris will help avoid the shelling.  The metric size is 0.1778mm.

100 grit belts and disks can also remove glass quickly with a new belt. Work at 100 grit until you get the shape or the big scratches are all gone from the 80 grit. As the belt gets worn, you may want to push harder to get the desired shape, but let the belt do the work. The metric size of this grit is 0.1397mm.

120 grit belts and disks remove scratches and still do some refining of shape.  The metric size is 0.1168mm.

200 grit belts and disks remove smaller scratches only. The shape of edge can still be adjusted, but only slightly. The metric size of this grit is 0.0737mm.

 400 grit belts and disks begin the polishing phase. Look for bigger scratches that you may have missed. The use of paint markers will help in this. Cover the the dry surface with the paint marker before beginning the polishing. This will show up any large scratches remaining after the first pass with the belt. If you find these, move back up to the level of grit that would remove any of the visible scratches, then work your way down again. The metric size of 400 grit is 0.037mm.

600 grit is a polishing phase. Take your time and move a little slower. At this stage, all the larger scratches should be gone and you are only polishing. The metric size of this grit is 0.020mm.

You can proceed to finer grits if you wish - such as 1200 (0.012mm) - but 600 is a practical grit at which to switch to cork and pumice, rouge or cerium oxide.

Cork is the final polishing phase before getting an optical finish with cerium oxide. The cork will grab the glass, so hold it securely. It is the friction between the cork and the glass that actually does the polishing. But do not let the glass overheat.

Grinding method You should not push hard with any of the grits. If you find that you want to get the work done more quickly, then it's time to put on a new belt or go to a coarser grit to remove the glass. You can use older belts as though it is a finer grit. The belts with finer grits will usually last a little longer than the coarser ones because the work is less agressive.

The grits of 100 and coarser are for shaping the piece.  The one you choose will be related to the amount of glass to be removed.  

After achieving the shape desired, it is usual to half the size of the grit (or in grit sizes - double the number) at each stage.  So after 100 grit, use 200, 400, and 600 one after the other.  

Of course you can do all this work without machines.  These grit sizes are available as loose powders.  The methods of working with a slurry of water and grit are described here.

Thinking About Design

To think about design, you need a vocabulary to describe the object. This needs to be combined with a structure of principles. What follows is an outline to structure your thinking about design.  This is based on the writing of Burton Wasserman in Spark the Creative Flame, Making the Journey from Craft to Art, by Paul J Stankard, 2013, pp. 25-27.

First there is the language to structure the conversation about design. The elements of this are “… point, line, plane, texture, colour, pattern, density, interval, … space, … light, mass, and volume”

Then there are principles of good design.  They relate to:

• ·         Unity – all the elements form a whole.
• ·         Balance – note, not only symmetry, but a distribution of elements that allows each piece to appear to be in its proper place.  Imbalance provides dissonance and tension which can be the purpose of the piece, of course.
• ·         Rhythm – this can be repetition with or without variation. This provides energy, animation to the piece.
• ·         Emphasis – or contrast between a main element and the rest. This can be size, colour or placing.
• ·         Harmony – all the elements work together to form a whole.

These five principles of design together with the vocabulary of elements assist your critical thinking about expressing your design and realising it in the best way you can.  This thinking can be applied usefully to the critical appreciation of others’ works.

I have grouped the elements according to the principles that seem most applicable as follows.  This organisation is not prescriptive. It merely helped me to think about using the language when viewing my own or others' work.

Design Language   

Vocabulary                                 Principles of Good Design

Point                                           Unity 

Line

Plane

Colour                                        Balance   

Light                                                        

Texture                                       Rhythm             

Pattern                                                     

Interval

Space

Density                                       Emphasis 

Mass                                                          

Volume

                                                   Harmony 

Flip and Fire

"Flip and Fire" is a term was devised by Brian Blanthorn to describe a process to achieve crisp details in the final piece.

The process takes advantage of two things - heat and weight. The glass on the shelf side moves less than the top as it is not quite so hot, and the weight of the glass above keeps the lines the way they were cut. The glass on the top of the piece begins to move first and fill the gaps that are left between the pieces.

This piece has been assembled with the final upper surface on the shelf and the base sheet placed on top.

The simplest method to achieve straight lines is to fire the piece with the final surface down to the shelf. After fusing, turn over and clean any surface contamination, usually by sandblasting. Wash and polish dry. Then fire the new surface to a fire polish temperature.

The same piece fire polished after cleaning the fused glass.

This technique works best on pieces that are of one uniform thickness.


There are other factors at play in obtaining crisp lines. 

Fusing straight lines

In addition to the "flip and fire" approach, there are a number of other factors that contribute to sharp, crisp lines in a piece made with strips of glass laid on edge and fused.

Smooth glass will fuse straighter than strips of textured glass. The individual strips fit closer together, leaving less room for lines to wander and create a wavy appearance.

The quality of the cut of the strip is important. Straight strips with right angle edges and no flares make for crisper lines.

The thinner the strips, the less opportunity for movement in the fusing when they are placed on edge. Ideally, the strips should be 6mm wide. This is the thickness that glass tends to take up when full fused. The greater the width beyond 6mm, the less likely the lines will be straight.

The viscosity of the glass affects the crispness of the lines. A glass that is less viscous will tend to be more wavy than a more viscous glass. E.g., black glass, a less viscous glass than white, will tend toward waviness more than the white. This is not a variation between manufacturers; it is a variation within a compatible range of glasses.

The firing surface will have an effect. Firing directly on a kiln washed shelf will give crisper lines than firing on fibre paper of whatever thickness.

Damming the composition before firing will produce straighter lines. The dam holds the strips in place during the heat up and restricts any flow that would be caused by strips thicker than 6mm.

Solder for Zinc

A number of people seem to have difficulty soldering zinc around their projects.  This is because zinc transmits the heat quickly – more quickly than the tin/lead solder – requiring more heat to be put into the process.  There is a solder that can make this process easier as it is designed for soldering zinc.

“Galvanite is a lead-free galvanizing solder formulation designed specifically for high quality repairs to galvanized steel surfaces. Simple, effective and easy to use, in both manufacturing and field applications. It metallurgically bonds to the steel, for a seamless protective barrier.”

https://en.wikipedia.org/wiki/Solder#Lead-free_solder

It composition is 50% tin, 49% zinc and 1% copper.  It becomes solid at 200C and liquid at 300C.  This makes it a high temperature solder for stained glass purposes, but will give a firm attachment between the zinc and the solder or lead came it surrounds.  The high temperature aspect means you need to keep the iron on the zinc rather than the more easily soldered metals or the glass.

Single Layer Slumping

Almost all glass can be slumped as a single layer, whether produced for kiln working or not.  A few are extra sensitive at even slumping temperature and change character at around 630C-650°C, but all others can be slumped.  This posts concentrates on slumping of single layers of non-fusing compatible glass, but most of these elements can be applied to fusing compatible glass too.

The things you need to take care about are:

• Temperature
• Soak Times
• Edges
• Devitrification
• Annealing
• Testing

It certainly is possible to slump single layers. The resulting glass will be slightly less robust than two or more layers of glass, but simply because it is thinner.

Temperature

The temperature that you use needs to be high enough to allow the glass to take the shape of the mould, but low enough that the glass does not distort or stretch and thin.  This is a balance that you can achieve through observation of the firing. 

It most often is best to use the lowest practical forming temperature that you can.  Practicality here is about how long you want to wait for the glass to conform to the mould.  It is possible to take the glass to about 580°C and soak for multiple hours, but not very practical.  It does depend on the glass as to the temperature to be used for the slump.  There are two sources here that can help: the slump point test  and this table of glass characteristics. 

Soak times

A practical soak time will be 30 – 90 minutes, which will avoid marking the underside of the glass.  This means that the temperature will need to be lower than the softening (or slump) point of the glass. Your slump point test will tell you the temperature at which the glass begins to deform.  That is the best temperature to use.  If it is taking too long, advance the temperature by about 10°C.  If you used the table of glass characteristics to find a softening point, reduce that temperature by about 30°C as a starting point.

Edges

The temperature that you will choose to use is not high enough to allow the edges to change as they would in a fuse.   This means that you need to have the edges exactly as you want them in the finished project.  This will require cold working by hand or machine.  Neither will take a long time, but require the correct tools. This post gives you the comparison of fused and cold working methods.

Devitrification

While most glass can be slumped you need to be careful with opalescent glass, as it can devitrify easily.  Most wispy glasses are fine, but the more opalescent wisps they have, the more difficult there may be.  Streaky and single colour glasses are usually fine. 

Annealing

Another element in slumping glass not formulated for kiln working is the annealing of the glass after the slumping.  The annealing temperature can be estimated as 40C below a low temperature slump of a 280mm span of glass. The slump point test mentioned earlier will help determine the annealing point. You need to soak for a time - maybe 30 minutes - at the estimated annealing temperature and then cool slowly in case you have miscalculated on the annealing temperature.  In any case, a long slow anneal cool will pay dividends in a more robust glass.

Testing

You will find some manufacturers’ glasses are less adaptable to kiln forming than others.  So, it is best to run tests on the glass before committing to larger projects.

Remember TADSET - temperature, annealing, devitrification, soak, edges, test.

Vinegar for Cleaning

Cleaning glass with acids causes corrosion of the surface of the glass.

So many people mention using vinegar to help clean the ground edges. I can't resist commenting. Vinegar is acidic. Glass is alkaline. Leave the glass in the vinegar too long and it will affect the surface of the glass.

Sometimes it dulls. Sometimes it corrodes to give a mild iridised appearance. The acid removes the alkaline materials – potash, lime, etc. – leaving a pitted surface at the microscopic level.  Left long enough – hours rather than days – the surface will begin to appear dull due to the pittiing. It is at this stage that it is easy to introduce contaminants which may later form nucleation sites for devitrification.

If you must use vinegar, rinse with it. Do not soak your glass in a vinegar solution.

Alkaline cleaners

Two alkaline substances that are used to clean glass are baking soda and ammonia.  Both are effective cleaners and do not have a reaction with the glass as they both are alkaline. The glass can be left to soak for a brief time in a solution of these chemicals, although I would not be happy with an open bath of ammonia.

But the effective part of what people are doing to clean the edges is the scrubbing. Scrubbing the glass powder out of the pits left by the grinder is what really works.  When leaving the glass in a bath of even plain water, you are giving the powdered glass the opportunity to settle into these pits.  Once settled into the pits, the powdered glass can become like cement to remove.

There is a much better cleaner, especially for removing kiln wash and investment mould material.  It is a neutralised acid - tri-sodium citrate.  It is often sold in the dihydrate form.  It is used in the food industry and so is widely available. Glass can be left in the 6% solution for days without being etched.  The unwanted material is chelated from the surface during this soak.  Occasional agitation may speed the effect by removing the loose material on top.

Mechanical cleaning

You could have a much better effect if you scrubbed under clean water before placing in a bath of water with grinder lubricant.  This material promotes a gel like glass residue. This gel prevents the glass becoming caked like cement.

A final scrub to thoroughly clean before assembly is a good idea. Each piece should be polished dry with lint free cloths or uncoloured absorbent paper.  If any particles cloth or paper are left behind, they will burn away long before devitrification can begin to form.

Of course, the best solution is to grind with 400 or 600 grit.  This is fine enough that there is not enough powder left to promote devitrification.

Devitrification on Ground Edges

The first element in preventing devitrification is cleaning.  Making sure all the edges of the glass are clean will help.  OK, you have cleaned the edges well after grinding. You still get detrification, so you want to know

Why do ground edges get devitrification? 

To answer this question, you need to think about how glass behaves in the kiln. As it heats up the glass expands, pushing the cut edges into the separator on the shelf. The pits caused by the grinding have not yet become fire polished.

When the glass retreats on cooling the pits in the edges of the glass, although very small, pick up some of the separator. These small particles act as the nucleation points for the crystallisation of the glass which is generally called devitrification.

The glass of a single 3mm layer retreats further on a single piece than on a 6mm piece. This rolls the devitrified glass upward onto the upper edge of the piece.

Prevention of devitrification of the ground edge is to have the pits in the glass edge finer than the particles of the separator. This is more than just washing the glass immediately after grinding to remove the glass powder from the grinding scratches.  Yes, this will reduce the chance for devitrification, but not totally prevent it.  As noted above, the pits in the glass will pick up particles of separator on expansion, giving nucleation points for the devitrification.

Further coldworking beyond the initial grinding is required to reduce the devitrification possibilities.  This involves using finer grinding bits or smoothing by hand with finer grits.  This does not have to take long, as the shape has been achieved by the grinder.

The logic of prevention is to have the glass edge smoother than the particle size of the separator, so the finer and smoother the separator, the smoother the surface of the glass edge must be.  

But my devitrified edge was on top of other glass

The follow-on question is about why devitrification occurs on ground edges that are not near the kiln shelf.  There are two elements to consider.

It is claimed that the fumes of the binder burning off can settle in the pits of the ground glass, providing those nucleation points for the glass crystalisation. The suggested solution is to vent the kiln to about 400C to allow the combustion fumes out of the kiln rather than keeping them inside the kiln.

The second and more certain element is that the grinding creates microscopic pits and fractures in the glass where the powder from grinding settles.  Almost no amount of cleaning will completely remove this residue from the tiny pits and fractures resulting from grinding. 

There are at least two solutions to this cleaning problem. Don't grind unless absolutely necessary - groze instead.  The second is to lightly cover any ground edges with clear powder frit.  You could of course consider ultrasonic cleaning or power washing, either with a dishwasher, or outdoor power washer.  Both these seem to be so completely out of proportion to the problem, that I have never used them.

Mandrels for Screen melts

In creating screen melts, the steel or other support left in the project can leave such a degree of stress that the piece will began to fracture over time.  The use of thin stainless steel rods as used in mandrels for bead making is an alternative, as they can be pulled out.

The separator used on the mandrel can be bead release.  If you have it that will work very well. This illustration shows a bead maker coating a mandrel from a bottle of mixed bead release.

If you do not have bead release on hand, you can use kiln wash.  To give the thick coating required to easily pull the steel out you need to mix the kiln wash differently. 

The normal mix of kiln wash would be 5 parts water to one of powdered kiln wash.  As you want this to be thicker so it will stay on the mandrel, you can mix it in a 3:1 ratio.  This will be sufficiently thick to keep it running off the mandrel and be able to extract it after kiln forming.

Mandrels prepared for bead making.  In coating them for a melt, you need to have the whole length coated.

To avoid the mess of pouring the wash over the mandrel, you can fill a stringer tube with the mixture and dip the mandrel into it. You can place the end of the mandrel into a polystyrene insulation block or a bit of clay to let it dry as done by bead makers.

Once dry, you can arrange these coated mandrels in any shape of grid you choose.  Lay them across your supports whether fibre board or brick with about 25mm on the support at each end.  Lay all of one direction down first and the follow with the second, or more layers.  Place you glass on top of the grid created and fire.

Assessing Pre-programmed Schedules

Many kiln manufacturers are shipping their kilns with a set of programs already entered and saved into the controllers. 

You might think that all these pre-set schedules would all be the same, as the range of glass to be considered is relatively small. Yet, the range of schedules for the same glass varies from one manufacturer to another.  Yes, you may respond, but every kiln is different.  Well, I’d say, the variation is within a product line as much as between kiln manufacturers.

Assessing the installed schedules

What this means is that you need to assess the schedules that come with your kiln, rather than simply accepting what has been placed there.  There are a few things that can be looked at to assess whether you wish to rely on these pre-set schedules or not.

Differences between fast and slow fuses. 

• ·         What are the initial rates of advance, are they different?
• ·         Where is the bubble squeeze, is there one?
• ·         Are there different rates of advance from bubble squeeze to top temperature?
• ·         If you can compare their larger and smaller kilns, is there a difference in schedules?

Differences between tack and full fuses

• ·         Are the top temperatures different for tack and fuse?
• ·         Is there more than one tack fuse temperature to allow for various levels of tack from lamination to fully rounded?
• ·         Is there a difference in soak times at the target temperatures?

Differences in slump temperatures

• ·         Are there low and high temperature slumps?
• ·         Is there a difference in temperature or time between various slumps?
• ·         Is there any allowance for span or size of mould?
• ·         Does depth of the mould make any difference to the schedule?
• ·         Is a difference for the depth of the mould offered?

Differences for different manufacturers’ glasses

• ·         Are there different schedules for Spectrum, Wissmach, Bullseye, etc. fusing glasses?
• ·         Are float glass schedules any different for rates, soak times, annealing points?

Printed schedules

• ·         Are the schedules printed in the kiln handbook or manual?
• ·         Are you given clear instruction on when to alter the programs?
• ·         Are you given clear instruction on how to alter the programs?

The more “no” answers you get to these questions, the less you can rely on the installed schedules.

Holding the Cutting Head

Many people hold their cutting head steady with a finger during the scoring process.  This is not necessary.

The axel of the cutting wheel is slightly forward of the centre line of the cutter.  In addition, the cutter is held slightly angled back toward the operator to be able to see the wheel and the cartoon (or marker) line.  Both of these act to ensure the wheel follows the movement of the arm or body in a forward motion. 

In cycling, the distance between the angle of the shaft of the cutter and the axel is called the “trail”.  The greater the amount of trail, the easier it is to keep the bicycle following a straight line. The same applies to the cutter. This trail is created by the extension of the angle of the cutter to the glass.  The axel of the wheel is behind that line. The cutting head has a sharper angle at the back than the front to accommodate this angle backwards. The resultant forward force is in front of the axel and so leads the wheel to follow the direction of the cutter without any need for stabilisation.

There is no need to have your finger on the cutting head. It swivels for a reason. It will follow the direction you are pushing without any angle, so there is a clean score.  If you attempt to stabilise the cutter head you risk the wheel running at a slight angle to the direction of the score.  I talk about this as a skidding score. The result of this is to give a score with forces directed not only straight down but sideways too.   This gives the glass many more ways to break.  And not always along the line you want.

Also when you want to score a tight curve, the slight movement of the head allows the curve to be slightly smoothed again without any skidding.  This means there will be fewer pressure lines sideways to the score line.

Manufacturers have put the play into the cutter heads for a reason.  The above attempts to explain it.  The manufacturers would not include a feature that costs time and effort, as well as cost if it had no purpose.  It seems perverse of us to try to run counter to that by holding the head or even fixing it solid, so it is unable to pivot at all.

Encapsulation of Fused Glass Panels

You can encapsulate both leaded and fused glass panels into double glazed units.

Leaded glass panels have the outer came built in “Y” shaped came.  The tail of the “Y” is held between the spacer bars at the edge of the double glazed unit. You normally need to leave 25mm space on each side.  It is calculated as the reduction from the glazing size of the opening.  This is required to accommodate the width of the heart of the came, the spacer bars and sealant of the double glazing assembly.

The same sizing guide is required for fused glass panels.  Usually the “Y” came is designed for 3 mm glass, as it has a 5mm high heart.  However, the “Y” is broad enough that the leaves can be opened to accept the thicker 6mm fused glass.  It is also possible to grind a bevel on the back of the fused glass to make it easier to slip into the came.

It is best to find the person or company which will be making the double glazing unit before starting.  Discussion with them at the start will enable you to determine how much allowance is needed for the spacer bars and the sealant. This will assure you in setting the dimensions for the panel you will make.

Making Your Own Schedules

Starting out with your own schedules is a bit frightening as you don’t yet know the capabilities of your kiln and the problems that might occur. This note attempts to give you some pointers on how to go about making your own schedules.

Start with the glass manufacturer’s recommendations.  Picking something from the internet or a discussion list may seem easy, but you cannot assess the quality of the posted schedules.  Many odd practices have crept into the kiln forming community. The manufacturers know their glass, so you should start there. They are the quality control standards for kiln forming.  Modifications will of course be required for your particular practice as it develops.

Enter the manufacturer’s schedule for the project you are working on and then watch while firing.  Watching does not mean staring into the kiln.  This would damage your sight after a while. This watching consists of quick peeks into the kiln to see what is happening.  These peeks will be at above 580C.  It is only then that there is enough light in the kiln to see what is happening.  At first the peeks will be at possibly only 30 minute intervals.  But as you near the target temperature, you will need to peek at possibly 5 minute intervals. The progress of the glass forming will be much quicker, so to know when the right temperature has been achieved, frequent peeks will be needed.

This observation will let you know if the glass is achieving what you want. If it is not, you can change the schedule while firing.  E.g., advancing to the next step in the schedule, extending the soak time, changing the working temperature to a higher point.  Be sure to read your controller manual to ensure you know how to do these changes during the firing.

If you have achieved the look you want before the target temperature has been achieved, advance the schedule to the next segment or ramp.  Record this temperature, as the next time you fire this set up you will want to be 5°C -10°C lower than this time.  You are aiming to achieve your look with a 10 minute soak.  So, depending on temperature, rate of advance and your kin, this lower temperature with a 10 minute soak should achieve your desired look.  Record this schedule. You will need to observe the next firing just to be sure the temperature and time combination you choose works. 

If the desired look has not been achieved by your top temperature and soak, you can raise the temperature 5°C -10°C, even if you have to interrupt the firing to change the temperature.  The controller will recognise which ramp is required to complete the ramp to the new top temperature without going through all the segments of the schedule.  Even if it does not, you can advance to the ramp you need.  The effect of these changes will be minimal in relation to the full and uninterrupted schedule and can be relied upon to work well on future firings.  Record the new schedule for future use.

An alternative to the change of the top temperature, is to extend the soak when the temperature has not achieved the effect.  You will need to keep peeking until the sought for profile is achieved.  Record this new soak time and the results for future firings.

As you can see it is important to record schedules, layup and results every time you fire.  This enables you to compare results and learn.  A log provides a good reference when you want to reproduce something that was successful.  It also records what did not go well and can remind you of what to avoid.

This process of observation, amendment on the fly, and recording actions and results helps you to get to your ideal schedule much quicker than by putting a schedule in and coming back the next day to see what has happened.

Diurnal Firing Practices

It is most common for people to fire overnight so they can see their piece(s) the next morning.   This is a poor practice for novices.  Not simply a lazy one. It is a practice that leads to use of others’ programs and practices, rather than building on one’s own experience and practice. Others’ programs are used because they were successful for them.  They may not be successful for you. The number of failed projects that are discovered when the kiln is opened, show that it is often not possible to transfer another’s schedule to your project.

The ability to fire while you are absent is a great advantage to kiln forming practices.  The widespread use of the controller has brought many advantages to kiln formers, not least that they can get some sleep and have a social life. They no longer need to be beside their kiln all the time it is firing.  The controller has also made it possible to set the ramp rates and soaks without calculations.  And without having to set periodic alarms to remind us to check the kiln to see if it is advancing at the correct rate.

Before controllers it was necessary to sit beside kiln to watch what was happening and adjust the ramps and soaks to conform to what was planned.  It was also necessary to observe how the glass was behaving and adjust the power input accordingly. Now we can set the controller to give what we hope will be a good result.  We find out when we open the kiln in the morning whether it is right or not.

I am not advocating returning to the days before controllers.  I enjoy my sleep and social life too much for that.

I am advocating the use of a feature almost all controllers have.  The Delay function.  On most controllers, it is the first thing that comes up on the display.  We mostly ignore that and proceed to the first ramp.  We set the controller to fire immediately, so that it will be done overnight and we can look in the morning or when we come back from work.  That way all the waiting for the piece to be finished can be eliminated.  We can go to work or to sleep knowing that the firing will be done when we can get back to the kiln.

This practice leads us to miss the real learning process that is available by observing the process of the firing.  Observing the firing can tell you when your slump is done, when it is slipping to the side, when it breaks, when more time is needed, when more heat is needed – almost everything that people ask questions about their slump – or in other instances, the fuse or melt.

People ask what temperature they should use for the kind of tack fuse they want.  Many suggestions can be made.  Trial and error will eventually tell which is the right combination of rate, temperature and time for the result you want. Observation during the firing will tell you immediately when the temperature is high enough, or the soak is long enough.  As you peek into the kiln through the observation ports you can advance to the next ramp when you have achieved the look you want. 

You do have an observation port, don’t you?  It is one of the essential features to be included in a kiln. If you don’t have one, you can open the lid or door momentarily to observe the state of the glass in the midst of the firing.  You could make an observation port by drilling through the casing and insulation.  You then place fibre blanket or a formed piece of kiln brick in the hole when not in use for peeking into the kiln.  You will not change the performance of the kiln by doing this.  Of course, if you have side elements, this retrofitting of an observation port is risky.


“I need a life.  I have to work.  I have to sleep.  I can’t be around my kiln all the time.” 

The legitimate responses to the idea that you should be around to observe the work at critical temperatures are that “I need a life.  I have to work.  I have to sleep.  I can’t be around my kiln all the time.” This is where the Delay function comes to your aid. You can use the Delay function to make sure the firing is at the critical point for observation at a time that is convenient for you.  This way, you do not disrupt your normal life.  Your social life can continue and you can get some sleep too.

An example will help understanding how you can make use of the Delay function. 

If you have time before you go to work, you can set it so that the firing comes to the critical point about an hour before you have to leave for work.  Or if it is better for you, you can set it so that time for observation is after you get home from work, or after dinner, etc.  Even if you don’t have a day job, you can use the Delay function to make sure you will be able to give the kiln the attention it needs at a convenient time for you.

How do I do this?  It is a setting of the amount of time to elapse before the kiln starts to fire on the first ramp.  Most programmes have firing times for each ramp.  You select the cumulative times up to the end of the ramp for the observation to begin.

This does not need to be difficult

This sounds complicated?  Not really.  It is a bit of arithmetic, though.  Add the times for each ramp together to get the time the kiln will take to get to the observation temperature and soak. 

E.g.:

200C/hour to 630C for 30 mins   =3.15 hours plus the 0.5 hour soak.  (divide the target temperature by the ramp rate, in this example 630/200=3.15 hours or 3 hours and 9 minutes).   Don’t include the soak time in this calculation as that is the part of the observation that is or may be variable.

Assume it is 10:00pm and you want to look at it at 7:00am.  This is 9 hours. The kiln needs 3 hours and 9 minutes to get to the temperature you want to observe the slump.  Subtract 3 hours and 9 minutes from the 9 hours you have and this gives you 5 hours and 51 minutes to set in the Delay function. 

Some controllers do not allow hours and minutes, but require only minutes.  In this case, multiply the hours by 60 and add the minutes.  In the example, there are 300 minutes in 5 hours plus 51 minutes gives 351 minutes to be put into the delay function. 

In this example, this will have the kiln at 630C at 7:00 am. Ready for you to observe the progress of the slump.  When the slump is finished, you can advance to the next segment and head off to work, allowing the cool and annealing to proceed, and knowing the slump was successful.  The same applies to other times of the day.  You could, for example load the kiln and schedule the delay to be at the critical temperature for when you come home from work.

Setting the delay function for an exact tack fuse is a little more complicated.

If you are looking to get an exact tack fuse profile, the schedule will be a little more complicated.  Say you want a rounded tack fuse that you think will be achieved at 750C in 10 minutes.  The schedule might look something like:

Ramp 1: 200C/hour to 650C for 30 minutes =3.15+0.5 hours =3.65 hours

Ramp 2: 300C/hour to 750 for 10 minutes =0.33 hours (750-650/300) + 0.167 hours soak.

Adding these two ramps together gives you 3.95 hours.  Here you include the soak at bubble squeeze temperature in the first ramp, but not in the second, because that is what you are checking on. If it is 7:00am now and you won’t be back until 6:00, that is 11hours until you will be looking in at the progress of your piece.  So you subtract 3.95 from 11 and you set the Delay as 7 hours, 57 minutes (or as 477 minutes).  Then it will be ready for observation when you come home.

Won't I loose firing time by using the delay function?

You may feel that you are going to lose a firing by using the Delay function.  You often can peek into the kiln in the morning to see how things have turned out by using the overnight firing.  But there normally is still more cooling down time required. 

If you delay the top temperature until the morning to see what is happening, you still have the rest of the day for the kiln to cool and be ready for re-loading in the afternoon or evening.  During that time, you can be preparing the next firing.  So you have not lost any kiln time, but you have gained the knowledge that the firing is OK through any adjustments you made at the critical temperatures.

If you were to fire during the day to be able to open the kiln in the evening as your normal practice, you will lose one firing at the start of this kind of practice.  As you progress with the new practice, you will find that you do not lose the number of firings you are able to complete in a week.  Again, you are preparing the next kiln load while the kiln is cooling.

Yes, it does require doing things a little differently.  But essentially it moves the kiln preparation on by 12 hours.  That’s why I call it diurnal firing.  You are just changing by 12 hours your daily practice. You make things ready for the kiln to fire overnight, and prepare the new piece(s) during the day.  Or prepare the pieces in the evening to fire during the next day.  You still are preparing the next kiln load as the kiln cools off from the previous firing.

The extra planning effort is rewarded by more rapid learning

This little extra planning is rewarded by the ability to see what is happening in the kiln, so that you can adjust during the firing, rather than having to do a firing again, or in the worst case, completely re-make a piece after a disaster. 

You also learn much faster about the desired programmes required to get specific results.  Instead of doing multiple firings to find the exact temperature needed for the desired result, you can do it in only one or two firings.  This saves you lots of time, glass and electricity. 

Observation is really necessary for free drops – aperture drops, screen melts, pot melts, etc.  These require observation to get the desired results, as their progress is so variable from one firing set up to another. Using the Delay function will enable you to have the firing at the stage where observation is important when you are best able to be there to watch.

The alteration to your working practices to make use of the Delay function will be amply rewarded by the rapid learning that observation of the firing promotes.  This essential tool to aid in designing appropriate firing programs is too often ignored in teaching and using firing schedules.

Finally, it allows you to set up programs that are pre-set for your kiln and kind of work.  You will have learned the exact rates and temperatures and soaks to put into your programs.  These become your saved schedules that are tailored to your practice.