Solder Alloys, 2

This is an updated version of a table on various possibly useful solders.

Solder Alloy	Composition	Solidus	Liquidus	Uses
25/75	Sn/Pb	183C	266C	general plumbing, car radiators
30/70	Sn/Pb	183C	256C	general plumbing, car radiators
30/50/20	Sn/Pb/Zn	177C	288C	economical solder for aluminium, Zinc and Cast iron
40/60	Sn/Pb	183C	238C	brass, plumbing, car radiators
50/50	Sn/Pb	183C	216C	general purpose, plumbing, not for gold, silver
50/48.5/1.5	Sn/Pb/Cu	183C	215C	reduces copper erosion on irons
60/40	Sn/Pb	183C	190C	electronics, good wetting, duller surface than 63/37
63/37	Sn/Pb	183C	183C	eutetic, electronics, stainless steel, bright joints
62/37/1	Sn/Pb/Cu	183C	183C	similar to 63/37 and reduces erosion on irons
90/10	Sn/Pb	183C	213C
95/5	Sn/Pb	238C	238C	plumbing and heating
96.5/3/0.5	Sn/Ag/Cu	217C	220C	recommended lead free for electronics
95.8/3.5/0.7	Sn/Ag/Cu	217C	218C	wave and dip soldering
95.6/3.5/0.9	Sn/Ag/Cu	217C	217C	eutectic
95.5/3.8/0.7	Sn/Ag/Cu	217C	217C	European preference for wave and dip soldering
96.5/3.5	Sn/Ag	221C	221C	wide use, poor wetting, strong lead free joints, stainless steel
95/5	Sn/Ag	221C	254C	strong, ductile joints on copper, stainless steel
94/6	Sn/Ag	221C	279C	strong, ductile joints on copper, stainless steel
93/7	Sn/Ag	221C	302C	strong, ductile joints on copper, stainless steel

Ag = Silver
Cd = Cadmium
Cu =Copper
PB = Lead
Sn = Tin
Sb = Antimony

Common stained glass solder compositions

Kilnforming Opalescent Stained Glass

The statement that a sheet of glass can be fused to itself is true in certain circumstances.  It applies to transparent and some streaky glasses best.  These forms of glass are more likely to fuse together successfully although not formulated for fusing.

Transparent and Streaky Glasses

Of course, the best practice is to test for compatibility.  I found in my early days of sticking stained glass together that it was beneficial to test. In doing so, I found Spectrum and Armstrong transparent and streaky glass to be largely consistent across many sheets.  I did not have access to much Kokomo or Wissmach.  I cannot comment on how their glass behaves in terms of compatibility across the production range.  Not all transparent and streaky glass remains stable at fusing temperatures. There are some glasses that opalise, some change colour, some devitrify. This variability makes compatibility testing important - even for the transparent form of stained glass.

Photo credit: Lead and Light

Wispy Glasses

The statement about fusing to itself is less applicable to wispy glass.  Not all the wispy stained glass from the same sheet can be fused.  It seems to be dependent on the amount of opalescence in any one area of the glass.  I found that it is possible - if you are very careful - to fuse certain Spectrum wispies with the clear fusing standard on top, but not on the bottom.  This should be applicable to other manufacturers’ wispy glass too.  There must be a marginal compatibility that is contained by the clear fusing glass on top, but I am not certain.

Photo credit: Lead and Light

Opalescent Glasses

The statement about fusing to itself is almost completely inapplicable to opalescent glass.  Stained glass opalescent glass does not have the compatibility requirements of fusing glasses.  They very often severely devitrify when taken to fusing temperatures.  This devitrification means that opalescent stained glass is often not compatible with itself.  So, no amount of twiddling with schedules will make stained glass opalescent glass fusible, even with itself.

Manufacturers have spent a lot of time and effort to produce fusing compatible opalescent glass.  It is as though there is a minor element of devitrification embodied in the opalising process.  Whether this is so, it becomes very apparent on doing compatibility testing that opalescent stained glass has severe devitrification at fusing temperatures.

Stock photo

Compatibility Testing

It is important to test for compatibility before committing to the main firing.  Some transparent and streaky glass changes colour, devitrifies, and some opalise at fusing temperatures. This applies with even more force to wispies.  They contain a significant proportion of opalescence within them.  Some opalescents are so unstable at fusing temperatures that the devitrification becomes so bad the glass crumbles.

The importance of testing pieces of the sheet for compatibility before committing to a firing is reinforced by these factors.

Slumping

Slumping temperatures are not so high as fusing, and it is often stated that single layers can be slumped.  Again, it is not always true.

Some glasses change colour at slumping temperatures.  A few opalise. It is not always certain what effect moderate temperatures will have on stained glass.  The compatibility testing will show.  Observe the test firing at slumping temperatures.  Also, you will learn if there are changes at moderate temperatures.

One element must be commented upon about slumping.  It is important to have the edges finished to the appearance that you want the final piece to have.  The regularity of the edges without bumps or divots, and the degree of polish need to be showing before the firing starts.  The slumping temperatures are not high enough to alter the shape or appearance of the edges.

Firing of stained glass to itself is normally a low risk activity, but with unpredictable results.  It can teach a lot about behaviour of glass at higher temperatures.  Slumping single layer pieces can give information about the way single layers of glass slump or drape.  But testing is important for fusing.  And can inform about how the glass will react at slumping temperatures too.

Cementing Leaded Panels, part 3

Polishing Lead Cames

Use a soft brush to polish lead came. Don't pick out the cement until the polishing is done, as it provides the colour for darkening and polishing the lead and solder joints. The action with the polishing brush should be gentle and rapid, much like polishing shoes. If the shine does not come, you can use a very little stove blackening (carbon black mixed with a little oil) If you use a lot, you will have a big clean up job. A little stove blackening spreads a very long way.

realglasspainting.com

Before turning the panel a final time, put down paper or cloth, to avoid scratching the solder joints while polishing the other side. The result should be shiny a black came and solder joints that does not come off the way a final buffing with stove blackening does.

Finally, pick out any remaining cement.

Rest horizontally with weather side down for traditional installations. If the panel is going into a double or secondary glazed unit, you may want to reverse this. The reason for having the smallest exposed cement line on the outside is to allow the water to run off the window with the minimum of area to collect. In a sealed unit or for secondary glazing, you may want to have the smallest amount of cement showing inward for appearances, as there is no weathering reason for the traditional method.

Rest for a day. Pick out the cement again. If the cement was stiff enough, there should be no need to do any more picking at the cement after this.

Cementing Leaded Panels, part 2

Part 2: Setting Up the Cement

After the pushing the cement under the cames on both sides, flip the panel over and begin a firm rubbing to push additional cement into the gaps between the lead and glass on this side. Sprinkle the used dust from the bench top over the panel and rub in all directions. This begins to set up the cement by helping to provide a stiff skin over the more fluid cement. Brush until the whiting is largely off the panel. Turn the panel and do the same for the other side. Several applications of whiting/sawdust are required to give a sufficiently thick skin to reduce the amount of spreading, leaking or weeping cement.

Once both sides have been done a couple of times, begin to concentrate the brush strokes along the lead lines rather than across. This will begin the cleaning phase and also begin to darken the came. Repeat this on the other side.

After a few turnings, most of the cement will be cleaned from around the leads. Don’t try to get all of it away, you will need that colour for polishing. The glass will be shining, and any felt tip marks you made on the glass will have gone too. Clean up the dust from the panel and bench in preparation for polishing.

Part 3

Cementing Leaded Panels, part 1

Part 1: The Start

Cementing panels is as old as leaded glass - about 1,000 years - so it is a time-proven process using simple materials. The object of cementing is to make a leaded panel weather/water tight and sturdy. It can be messy and dusty, so putting on an apron and a dust mask are a good idea.

Start on the side that is already facing up after soldering. This normally will be the rough side. This way you do not have to move the panel much until it has stiffened with the addition of the cement.

Cover all open bubbles, rough glass (waffle, ice, etc.) and all painted glass with masking tape. Put the tape over all the relevant areas of the panel, then use a sharp knife (X-acto, scalpel) to cut the tape at the edges of the came. The cement will go under the came, but not into the texture of the glass. This will make the clean up of the glass much easier after cementing.

You can purchase commercially made lead light cement or you can make your own.

With the panel on the bench, put a dollop of cement on the glass and rub it in all directions with a stiff, but not hard, bristle brush to force it under the lead. 

Bovardstudio.com

When the cement has been pushed under all the cames, but with a slope of cement showing, spread a little fresh whiting or sawdust on the panel and gently push it against the cement under the leads. This begins the setting process and keeps the spreading cement from sticking hard to the glass or bench.

bovardstudios.com

Turn the panel over to cement the second side the same way as the first. If the panel is a large one, you may want to use a board to support it in these early turning stages. No gaps can be tolerated in the cementing. Cement leaking out the other side is good evidence that all the gaps between the glass and the came are filled. Again, after cementing, sprinkle new whiting/sawdust over the second cemented side and rub it gently into the exposed cement.

Part 2
Part 3

Pricing, 3 - Terms and Conditions

Terms & Conditions

It is important to draw up your terms and conditions for both trade customers and for the public. They should include:

• Details of your minimum orders
• Carriage/delivery - is it free or charged to the customer?
• What is the recommended retail price? It is useful to include this, as you will often be asked to provide a figure by shops.
• Any conditions about display or point of sale material (if you provide any)
• Credit terms
• What deposit is necessary - when a member of the public places an order always take a deposit or ask for full payment in advance.
• Details of any interest charges that you will charge on any outstanding debts.
• Once an order is placed, get the customer to sign it and make sure they are aware of the relevant terms and conditions.

More information is available 
Establishing the costs
Creating a pricing structure
Terms and conditions of sales
Customer relations

Payment

Iridescence

What is it?       How permanent is it?

“Many special effects can be applied to glass to affect its colour and overall appearance. Iridescent glass … is made by adding metallic compounds to the glass or by spraying the surface with stannous chloride or lead chloride and reheating it in a reducing atmosphere.” 

Older glass can appear iridised because of the light reflection through the layers of weathering.

“Dichroic glass is an iridescent effect in which the glass appears to be different colours, depending on the angle from which it is viewed. This effect is caused by applying very thin layers of colloidal metals (e.g., gold or silver) to the glass.”

Source: https://www.thoughtco.com/

A rainbow iridescent appearance caused by an oil film on water is seen by light being reflected from both the top oil surface and the underlying water surface.  The light reflected from these two surfaces or boundaries have slightly different wave times and so interfere with each other to create this colourful pattern.

This is also observed in soap bubbles.  Here the light is reflecting from both the inner and outer surfaces of the film.

This iridescent appearance is termed thin-film interference.  It is an occurrence in nature where there is a thin film through which light can penetrate and so reflect off the surfaces of the film.  These surfaces are termed boundaries where the light can reflect. 

The thickness of the film can enhance or reduce the iridised effect. 

At a certain thickness the light waves reflected can cancel each other out.  This is described as a destructive interference pattern as it reduces the reflection.  The phenomenon can be used to provide non-reflective surfaces.

At other thicknesses there is an iridised effect.  This is caused by the reinforcement of the recombination of the two light waves reflecting in phase or nearly so.

Control of the thickness can give the silver or the gold iridised appearance, as in the Bullseye iridised glasses, in addition to the rainbow and other effects.

The nature of the light affects the colours of the iridescence.  If the light is daylight or similar it is a combination of many wavelengths.  The different wavelengths reflecting from the “boundaries” or surfaces provide the multiplicity of colour.  If the film has variations in thickness, there will be variations in the colours created.

A diagram from Wikipedia shows how the reflections work at the microscopic level.

https://en.wikipedia.org/wiki/Thin-film_interference

The permanence of the film causing the iridisation appears to be dependent on the metals used and the way in which they are deposited.

Orientation of Cutter Heads

In addition to the alignment of the cutter, you need to be sure you are moving the cutter forward in the way it was designed. If you look at the cutter from the side you will see two things. The most obvious one is that the angles of the cutaway on the head are shallower at the front and steeper at the back. In addition if you look carefully, the axel for the wheel is slightly forward of the centre line of the whole cutter.

Cutters aligned to score to the left

So it does not matter where the fixing screw on the head is. It may be at the front or at the back. What matters is the cutaway at the back which allows the cutter to be used with a shallower angle, than if reversed. This is most obvious on wide cutter heads.

Cutters arranged to score to the right

Avoid Finger Cuts at the Grinder

Before serious grinding, first run the whole perimeter of the piece very lightly against the grinding bit. This removes the worst of the 'scalpel' edges and avoids the micro cuts on your fingers.

And,

Let the grinder do the work. Many people seem to put huge pressure on the piece to grind away the waste more quickly, but this is actually counter-productive. Less pressure means less fatigue, less chipping at the edges, fewer broken pieces, and most importantly, fewer cuts to the finger tips.

Glue chipping, 9

Glue Ratings

The glue used for chipping glass is generally called animal hide glue. Many companies sell animal hide glue, but to get the best results, you must use glue that has been formulated and tested for strength.

There are many grades available, such as:

80, 110, 135, 164, 192, 222, 251, 280, 315, 347, 379, 411, 444, 478, 512 jelly gram strengths

The three grades suitable for glue-chipping are:
5x (weakest) = 135 gram strength
4x (suggested) = 164 gram strength
3x (stronger) = 192 gram strength

Glue chipping, 7

Variables Affecting Chipped Patterns

The glass chipping pattern is subject to many variables. The duplication and uniformity of each pattern is dependent on control of these variables.

There are many variables to be considered, The major ones are:

1. Glass - type and surface preparation
2. Room temperature during preliminary drying stage
3. Glue - type, concentration, and temperature at time of application
4. Weight of dry glue applied per area of glass
5. Dryness of glue film at end of preliminary drying stage
6. Temperature of drying room during chipping process

Glue chipping, 6

Secondary Drying and Chipping Stage

The secondary drying and chipping stage is when a small space heater can be used to warm the glass up to around 52C (125 F). Do not point the heater directly at the glass. Keep it at least one metre away from the glass. You don't want to cause the glass to get too hot and crack.

This indirect heat will cause a rapid evaporation leading to curling of the glue and the chipping of the glass surface. The glass is under extreme stress at this point and should not be handled unless absolutely necessary. On sunny days the glass can be set in direct sunlight. This is the easiest way to get the glue to chip the glass.
The chips of glue can pop off and travel some distance, so take appropriate precautions, i.e. safety glasses, gloves, aprons. You might want to place a cloth over the surface.

After all the glass is chipped, some glue may still be left on the glass. The glue is water soluble, so you can soak the glass with warm water and scrape off the softened glue. Be careful of the extremely sharp shards that are now concealed in the water.

The glue and glass shards left from the chipping process can create a big problem if not cleaned up. Because the glue is an animal by-product, cats and dogs love to eat this stuff. This can cause your pet extreme harm and even death! Dispose of the waste carefully.

Glue Chipping, 5

Drying time

The glue will go through an initial drying stage. This is in the first hour or two, depending on the humidity and temperature of the room. Make sure to keep the glass level during this period.

The next drying stage takes between 12 to 24 hours. This is where the glue will cure and loose almost all of the liquid. A fan to circulate the air will speed up this process. The glue should be left to dry at its own rate, do not hurry it by heating. Uneven curing may result in a poor chip pattern.

The secondary drying and chipping stage is when the glue actually starts to peel or chip. The glue shrinks considerably during the total drying process. As it shrinks, it grips into the pores caused by the sandblasting and literally rips the top of the glass off.

Use precautions when handling glass that has a dried layer of glue. Goggles, gloves, aprons are the minimum precautions against the slivers of glass.

Glue Chipping, 4

Applying the glue

The glass should be clean and have a dam around it.

Cleaning the glass is important. If there is dust left from the sandblasting/grinding stage, the glue will not stick to the glass.

Place the glass on a level surface. The glass should be room temperature.

Pour the glue onto the glass in an even layer between 1mm to 3mm thick. If the glass is level the glue will flow to a uniform thickness on its own. You can tilt the glass from side to side to help the glue flow.

CAUTION: If your glue is too hot, it may shock the glass causing it to break, allowing the glue to run all over the place. Another reason to avoid heating the glue to a high temperature.