Soldering Iron Temperatures

Why use higher temperatures for copper foil using 60/40 than lead came using 50/50 or 40/60? Melting temperatures Part of this is the physical characteristics of the solder The graph shows that all compositions of tin/lead alloy solder (above 20% tin) solidify at the same temperature - 183°C.  Pure lead melts at 327.5°C and pure tin at 232°C.  The various proportions of the two metals melt at different temperatures until at approximately 62% tin, the melting and solidification temperatures are the same.  This is ideal for running a bead in copper foiling, because there is a minimum amount of time for the liquid solder to change shape before it solidifies. Melting temperatures of some solders ·        At 40% tin and 60% lead (40/60) the melting temperature is 238°C.  ·        At 50/50 the melting temperature is 212°C.  ·        At 60/40 the melting temperature is 188°C, just 5°C above the solidification temperature. These figures show the 60/40 solder requires a lower temperature to melt than 50/50 does (24°C difference).  Why should I run the iron at a hotter temperature for 60/40 then? There are two separate elements at work here – the mass of solder being melted and the effects of the pasty range of solder compositions. In soldering lead came you are melting small masses of solder with short pauses between each melting that allow the iron to partially recover. This means running the iron at 370°C is sufficient to maintain a melting temperature above 238°C for 40/60 solder and 212°C for 50/50. In copper foil you are melting much greater amounts of solder, which takes heat out of the iron more quickly than in leaded glass.  The fact is that running a bead requires melting a much greater volume of solder.  The iron needs to run hot to be able to consistently melt the solder without significant periods when the iron is too cool to melt the solder quickly.  This is the reason that irons are run hotter in copper foil. It still does not explain why it is recommended to run the iron hotter for 60/40 than for 50/50 as their melting temperatures are so close. The explanation lies in the pasty range illustrated in the graph shown above.  You can run an iron hotter than needed to melt the solder, because the 60/40 requires fewer degrees to cool and solidify than 50/50.  This allows you to work quickly and still have a good rounded bead. The greater pasty range of 50/50 means that you must be careful about the amount of heat you put into the solder, because the solder will continue to move for a longer time than the 60/40.  The 27°C difference between melting and solidification shows solidification is not instantaneous. This pasty range allows flow while the solder cools. This means that the bead will be less rounded, and it will show minor temperature differences in the wrinkled surface.  If you put even more heat than the 410°C that is normally used for 60/40, it will take even longer for the solder to solidify.  The surfaces effects will then be even more obvious with greater heat.

The short answer

The explanations for running hotter with 60/40 than those solders with more lead centre around the pasty range of solder.  When the pasty range is small, you can put more heat into the solder bead and so work more quickly and still get a good bead.  With wider pasty ranges you need to reduce the temperature of the iron to reduce the heat put into the solder and so keep the pasty range as small as possible.

Oxidisation of Foil

Often, life intervenes between foiling and soldering.  This frequently results in the foil not accepting the solder very well, because of the mild tarnish that has occurred in the meantime.

It is a good idea to clean the foil of any possible corrosion before soldering when there has been an interval between the two processes. It is enough to clean foil with a mild abrasive such as a foam-backed scrubber from the dish washing, or fine steel wool.  I prefer the scrubber as it does not introduce another metal.  

Some people prefer a vinegar and salt solution to apply to the tarnished foil.  I am concerned about the introduction of an acid into the process causing further problems later.  I don't recommend this method of cleaning.

I then coat the exposed foil with a film of paste flux to protect from further tarnish. This acts better than any loose covering of cloth or plastic to protect from oxidation.  The purpose of flux is to both provide a "wetting" agent for the foil to accept the solder,  and to prevent oxidisation. Liquid flux cannot provide protection, once dry,  from the copper tarnishing.  I prefer the use of paste flux to reduce boiling of flux and to keep the copper free from corrosion.  The paste flux will not indefinitely prevent oxidisation, but will do so for a week or two.

Turning Panels

Panels should be turned by supporting as much of the panel as possible. In general this means that the panel should be moved until about half of it is off the bench and supported by one hand. Then pivot the panel on the edge of the bench until it is vertical. During this process, the other hand should be supporting the other edge.  Pivot until vertical.  Lift and set it on the bench. Turn it around, keeping it vertical. Lift it off the bench and set the middle against the edge of the bench with one hand on each otherwise unsupported edge. Pivot the panel on the edge and slide it back on the bench.


If the panel is going to be a large one, make it on a board placed on top of your bench. Then when it is time to turn the panel, you can tip the board, set the panel together with the board on the floor. Move the board to the other side of the panel, turn the board around, placing it against the edge of the bench and raise it while pivoting it on the bench. Additional help is to have two short pieces of wood on the floor to set the panel and board on, so you can get your fingers under easily and without getting them trapped.


If you have the space and spare boards, you can place a second board on top of the panel. Make sure the panel is at the edge of the boards next to you. You can then, with the help of another person, turn the whole panel in one movement (although your arms will be in a bit of a twist). This removes the danger of the panel wobbling too much while shifting the supporting board.


A panel of any size with one or more long lines going through the panel should be made on a board, so that it can be turned without the danger of breaking any of the glass or of the panel folding along the lead lines.

Textured Side

There is a little concern about whether the textured side of the glass pieces in leaded and copper foiled glass should be towards the inside or outside.

The traditional advice is to have the textured side toward the inside.  This is based on the piece being used as a window. It is easier to keep the weather side clean if the smooth side is on the outside. The same thinking leads to the recommendation to allow the cemented panel to rest with the smooth (outside) down.  This minimises the thickness of the putty and so allows less water to collect on the outside horizontal leads.

If the window is not primary glazing, it does not matter which side, nor how consistent you are in placing the glass.  It becomes a matter of aesthetics – which ever way you prefer is fine if it gives you the effect you want.

There is a small visual effect if you are using transparent glass.  There is slightly more dispersion of light if the textured side is outwards. 

Placing the textured side inwards can be useful if you wish to indicate a rough surface contrasting with a smoother one.

These considerations show that the placing of the textured side is largely determined by the function of the panel and the aesthetics applied.

What Cartoon Lines Represent

A frequently asked question by novice glass workers is whether to score at one side of the line or in the middle.  This question revolves around the meaning of the cartoon lines.  What do the lines of a cartoon represent?

Meaning of Cartoon Lines

The lines on a cut line cartoon represent the space required between pieces of glass.  This will vary, depending on the style in which you are working.  In most glass working, a matrix of lead or foil is used.  The space required by these materials needs to be represented in the cut line cartoon. You may have other cartoons for other purposes – painting, came width, foil width, etc., but the lines in the cut line cartoon are there to represent the space required between pieces of glass.

An example of a cartoon for painting

Lead Came

In general, a 1.2mm line is required for standard lead came. This is close to the line made by a new bullet pointed felt tipped marker. If you are working with high heart cames, you will need a 2.8mm wide line. Some chisel point markers, if used on the sharp edge have this approximate width.

The glass is scored at the inside edge of the cartoon line.  This can be done by scoring directly on top of the cartoon, often with a light underneath.  You can make pattern pieces when the glass is too dense for enough light to come through.  If you must, you can draw the score line on the glass. You can score around pattern pieces, but if your scoring wheel goes over the pattern in any place, the scoring pressure will not be delivered to the glass.

Example of came varieties

Copper Foil

In copper foil, a much thinner line is used as the space between pieces of glass needs only be approximately 0.4mm. This is approximately the width of a sharpened pencil or ball point pen line.

The scoring is at the edge of the line as for lead came.  Also, you can score directly over the cartoon, draw on the glass, or make pattern pieces as for lead came projects.

Fusing Cartoons

When preparing a cartoon for fusing, the lines need to be as fine as possible.  The pieces of glass require no space, as they will be butted against each other.  However, unless cutting by computer controlled instruments, the cutting cannot be completely accurate, so the same size of line as for copper foil will do.

As you are going to try to butt the glass pieces together in fusing projects, you score along the middle of the cartoon lines.  As much as possible, cutting over the cartoon will give the best result.  Of course, there are many times when the light is not good enough and pattern pieces will be required. 

Another approach is also possible. Having scored and broken the first piece, you can place it on top of the glass to be cut for the adjoining one.  With a very fine felt tip or fountain pen, trace the edge of the first piece. Score down the middle of that line to create the best fitting second piece.  And so on through the whole project where the glass is not too dense to use a light box.

Conclusion

The line widths in a cartoon are determined by the space required between pieces by the assembly method.  The thicker the matrix material, the thicker the line and vice versa. 

Grinding to Fit

In copper foiling, a considerable amount of work goes into getting the pieces to fit with just enough space to accommodate the copper foil and a thin space for the solder fin to join both sides.  This of course, promotes consistently narrow solder lines without the solder melting through to the opposite side.

Grinding to pattern

Many times it is necessary to grind to fit pieces together with this degree of accuracy.  Those who draw onto the glass or stick pattern pieces to the glass, often grind to the template or the drawn lines.  This can lead to inaccuracies in relation to the cartoon.

The object in scoring and breaking the glass is to be as accurate as possible.  This reduces the amount of grinding required.  It saves time. It makes the whole process easier.  Still, we all have to grind relatively often.

Grinding to cartoon

In my view, when grinding to fit, you should be trying the piece out against the cartoon, rather than the template or the drawing on the glass. This will tell you how well the current piece fits in with the rest of the pieces you have already fitted to the cartoon. 

The cartoon drives the assembly of the whole piece.  Thinking you can just make small adjustments as you work along, creates increasing difficulties in making the whole fit together.  If you follow this principle of fitting to the cartoon, you are judging the accuracy of the piece against the cartoon lines, rather than any template or drawing on the piece of glass.  This means that the fit will be correct and the whole will go together with the minimum of difficulty.

Foiling Space

There are a lot of views on what amount of space is required between copper foiled glass pieces.  Some say the pieces should be tight, others that a consistent space is needed, and some who say that variable spaces are fine.

It is necessary to consider what holds a foiled panel together.

Adhesive

The foil is supplied with an impact adhesive which helps keep the foil attached to the glass before soldering.  However, the heat of soldering deteriorates the adhesion of the glue.  If you must take a foiled piece apart you will find that the adhesive is sticky rather than firm. Also, the adhesive will continue to degrade during the life of the object.

Solder

The solder bead is significant in creating the matrix required to hold the panel in one piece.  The bead on each side holds the glass in place and resists deformation away from a single plane. This resistance is significantly reduced if there is not a fin of solder connecting the two beads.  The beads and the fin of solder form an “I” beam which together resists movement of the glass.

Strength

To form that “I” beam there does need to be space between the foiled pieces. It does not need to be wide, but it does need to be enough to wiggle the pieces.  This will allow the solder to flow from one bead to the one on the other side, forming a strong “I” beam.

In vertical panels, the glass is the strong element.  The solder lines serve to hold the matrix together.  Where people indicate the strong border will keep the whole panel from falling apart, they are correct in part. But, if there is not a sufficient “I” beam between each piece, the whole panel is subject bowing, either from wind pressure, vibration or mechanical pressure from handling.  Therefore, you cannot rely on the border to make your panel strong and long lasting.

Dissent

Some take the view that there will be enough unintentional spaces created between pieces to allow the fin form between beads intermittently.  But the gaps in the “I” beam due to tight fiting pieces will make it much weaker than a continuous bridge between beads.  The existence of gaps puts greater pressure on the solder that does bridge between beads.

An example was provided for me in a lamp brought in by client which spontaneously fell apart one evening.  (Not made by me, I add). The upper band of glass remained attached to the vase cap, but separated from the rest of the shade.  Fortunately, it fell straight down and only a little of the bottom edge was broken.  Investigation showed there was very little solder between pieces, although there was a good bead on each side of the lamp.  The lamp pieces separated, in different places, at the foil-glass interface and elsewhere at the foil to foil interface.  This indicates there was little or no solder where the foil remained on the glass, as the adhesive is much weaker than even a thin fin of solder running between the inner and outer beads. This case is an example of the need for a fin of solder to be formed between the beads on either side to provide a strong, long lasting object.

Heat Cracks

There is sometimes a fear expressed that tight fitting of foiled pieces can lead to heat fractures when soldering due to expansion.  Yes, when soldering pieces with a lot of variation in width, you do need to move reasonably quickly. Come back later to improve a bead if you need, to avoid overheating the glass.  Even the thin copper foil can transmit heat along its length, which reduces direct heat transfer to the glass.  Mostly, breaks occur from dwelling too long in one place with the soldering iron. It may be better to tin the foil all around the suspect piece just before running the bead.  This will warm the glass around the edges in preparation for the greater heat of laying down the bead.

The main point is that the solder needs to connect the beads on either side of the glass to provide a stable, strong and long-lasting piece.

Foiling and Soldering Small Pieces

There are several approaches to dealing with small pieces in copperfoiling:

No-foil approach
One approach is to have some of the pieces held in place by over-beaded solder without foil on the tiny piece, but it is patchy at best and likely to lose pieces in the long term.

Bevel approach
A very good and strong approach is to partially 'bevel' the edges of each piece on both faces. Grind at 45 degrees until the very edge is only 1 mm thick. Then use foil that is 4 mm wide for 3mm thick glass. For 4 mm glass, you will use 5.4 mm foil. Make sure that the foil covers only the bevelled edges and does not extend outside them.

Solder into the 'V' formed by the bevelled edges. Don't over-fill the joints as you don't want solder outside the 'V'. It also is best if the panel is supported underneath the area being soldered by a wet sponge to more quickly cool the solder.

With the solder contained by the 'V', the solder lines will be of constant width throughout the piece. Best to practice this technique on some scraps before you start the main job.

This approach will minimise the amount of light blocked by the foil - important with tiny pieces - while still providing the strength of fully foiled pieces.

Triming approach
If you have to have really small pieces, just foil them as you would any other piece, and burnish it as normal. Then take a very sharp craft knife (Exacto or similar) and trim the foil so that just a little tiny bit of foil is on the front and back of the piece.

No glass approach
Tiny pieces are really tedious to work with. So if the piece is going to be black or really dark, for example a small hummingbird's beak, or a bird’s eye, don't bother with glass but just fill the space with foil and solder.

White solder beads

It is relatively common for questions about white deposits on the solder beads of copper foiled pieces to be raised. In reflecting on the cause of the white deposit on solder beads, I recalled that some people use baking soda to neutralise the flux.  I put this together with some work on lead corrosion.

I have been doing a bit of research on lead came corrosion in another context.  One of the forms of lead corrosion is white lead corrosion, or lead carbonate.  It has the chemical compound PbCO₃.  It is a curious compound, as it is soluble in both acid and alkali.  This much you will have seen from a previous posting about lead corrosion.  

In that it is possible for excess whiting left on lead cames to give rise to this form of white corrosion. Baking soda has a chemical formula of NaHCO₃.  Solder contains a significant amount of lead – usually 37-40%.  The chemical reaction of lead and baking soda gives lead carbonate - PbCO₃ and NaH -sodium hydride.  The sodium hydride is soluble in water, leaving the white deposit of lead carbonate as a corrosion product on the surface.

Putting these things together leads me to recommend that baking soda and other carbonates should not be used in cleaning solder beads.  Some other non-carbonate neutralising or rinsing agent should be used instead.

Does Wider Foil Give Greater Strength

The strongest part of a stained glass panel, whether leaded or copper foiled, is the glass.  The weaker points are the matrix that holds the panel together.

Of the matrix, the solder is the strong part.  The copper foil is weaker (and much thinner) and the adhesive is the weakest part of all.

A wider bead gives more apparent strength, but on the surface. It provides a broad line to grasp the glass.  But wide beads are often not what is visually desirable, nor practical.  And the wider the bead, the more solder will be used.

The most important part of a panel is the thin fin of solder between the top and bottom of the solder beads.  This is the connector between front and back. The strength of the whole panel depends on that fin.  So, it could be argued that very closely fitting foiled pieces lead to a weaker panel than loosely fitting ones.  I would not argue that, but it is important to have that connector of solder between the surface beads for a panel to be strong.

The solder connects the two solder beads together and forms the matrix which holds the panel together.

Here the fin of solder is a little thinner, so the matrix is marginally weaker

For larger panels, reinforcement will be required, either between the glass pieces, or on the surface.  The fact that reinforcement is so often used in the gap between the pieces, is confirmation that the fin of solder between the front and back is very important.

Plating in Copperfoil

Plating is used to modify the colour, or intensity of local areas in a window or panel. Plating for leaded glass is normally putting two pieces of glass in the same came, although there was a common practice at the turn of the 19th into the 20th century to have the plate cover several pieces of leaded glass. In principle, the plating of copper foil panels is the same as for leaded glass, except there is no came to fit the glass into. So there are some variations.

An example where the fruit and leaves are all plated

Build the flat, single thickness window first. This provides a solid panel to work on. It also enables you to see whether you really need the plating, and if so the exact areas where it will be applied.

You should solder the whole panel except where the plate is to be soldered. In this/these areas just lightly tin the back, although you will have already put a solder bead over the whole of the front.

Patina the back of the panel, except where the plate is to go. Allow this to dry and clean up any spills, especially in the neighborhood of the plating.

Foil the plate with a backing to match the colour of the patina. So use copper-backed foil where the panel is in copper patina, but black-backed where the patina is black.

Tin the foil on the plate with solder. If the piece is to cross a number of the base pieces, you need to patina the tinned face that will be placed toward the viewer with the same colour patina. You need to make sure this is absolutely dry before proceeding.

Clean the plate and the base glass where the plate is to cover very well. Make sure there are no oils or tarnish on the solder, and that everything is dry.

Solder the plate to every seam that it contacts with no flux and a small amount of solder. This is to insure there is no leakage of flux - by not using any - or solder between the two pieces of glass.

Put a small amount of clear silicone between the edge of the plate and the base glass where you were not able to solder. Just lightly fill the gaps to ensure a seal against moisture and insects.
When the silicone has cured, carefully patina the plate so no fluid seeps between the glasses.

Protect the uneven back when handling by placing a soft foam pad, or a polystyrene sheet with cutouts for the plating, on the back to protect the panel from the carrying board.

Hangers for Sun Catchers

Unless you are using some manufactured system or a frame, the most frequent way to provide hanging points for copper foiled sun catchers is to create a loop from copper wire.

Hangers should originate in a solder bead that goes some way into the piece. The loop's tail should lie a significant distance into the solder line to ensure it does not pull the piece apart. If this is to remain invisible, some planning will be required to allow the small extra space between the foiled glass.

The loops for hanging a piece of any size should not be soldered to the perimeter foil without reference to the solder bead lines within the piece, as the adhesive and foil are insufficient to hold the weight without tearing.

Reinforcement of free hanging or projecting elements can be done by placing wire around the piece with a significant excess going along the perimeter in both directions. The supporting wire can go into the solder line, if it is a continuation of an edge of the free hanging piece.

An example of a piece that needs reinforcement around the wings to keep them firmly attached to the body

The strongest method of proving hangers is to wrap the wire around the whole perimeter of the piece. Choose easily bent copper wire. This will be pretty fine, but when soldered, will be strong enough support the whole piece.

The perimeter wire can also be concealed by edge cames

The hanger can be made by leaving a loop of wire free along the perimeter. This way you can hang from any convenient place on the perimeter. This loop can be made by a single 180 degree twist in the wire, or by bending a loop into the perimeter wire. In all cases you will need to tin the wire to blend it with the rest of the piece.

An example of wire running between the yellow and purple on the left and incorporated into the design

This perimeter wire can be simply butted at the start/finish of the wire. It could be overlapped, but this is unnecessary on any piece where this method is adequate for support. The start can be at the top or bottom, although I prefer the top, so the wire is continuous from loop to loop. The reason for continuing beyond the loops is to provide support to all the edges of the sun catcher.

Hanging Sun Catchers

Unless you are using some manufactured system or a frame, the most frequent way to provide hanging points is to create a loop from copper wire.

Hangers should originate in a solder bead that goes some way into the piece. The loop's tail should lie a significant distance into the solder line to ensure it does not pull the piece apart. If this is to remain invisible, some planning will be required to allow the small extra space between the foiled glass.

The loops for hanging a piece of any size should not be soldered to the perimeter foil without reference to the solder bead lines, as the adhesive and foil are insufficient to hold the weight of the piece without tearing.

Here the hanging loops could have been moved just a little to engage with the solder joints at the left ear and at the tail to make stronger hanging points

Here the hanging points are at the solder joints giving strong hanging points

Reinforcement of free hanging or projecting elements can be done by placing wire around the piece with a significant excess going along the perimeter in both directions. The supporting wire can go into the solder line, if it is a continuation of an edge of the free hanging piece.

In this case a twisted copper wire around the perimeter gives strong hanging points

The strongest method is to wrap the wire around the whole perimeter of the piece. Choose easily bent copper wire. This will be pretty fine, but when soldered, will be strong enough support the whole piece.

The hanger can be made by leaving a loop of wire free. This way you can hang from any convenient place on the perimeter. This loop can be made by a single 180 degree twist in the wire, or by bending a loop into the perimeter wire. In all cases you will need to tin the wire to blend it with the rest of the piece.

This perimeter wire can be simply butted at the start/finish of the wire. It could be overlapped, but this is unnecessary on any piece where this method is adequate for support. The start can be at the top or bottom, although I prefer the top, so the wire is continuous from loop to loop. The reason for continuing beyond the loops is to provide support to all the edges of the sun catcher.

This single point hanger is at the strong point of the piece

The left hanger is strong, but the right is weaker than if it had been attached to the right of the body

This piece needs wire around the piece, especially to stabilise the tail and ears

Space In Copper Foiled Projects

When cutting for copper foil projects it is important to leave a small gap between the pieces. This is both to allow for the thickness of the foil and for the solder to form a bridge to the other side of the panel.

I prepare the space in the cutting process by scoring at the edge of the pencil thin cartoon line. This leaves the thickness of the line between the pieces. I do not use pattern pieces unless I am using very dense opalescent glass. When I do use pattern pieces I cut them out with a scalpel knife so there is no space between the pattern pieces. I then draw around the pattern pieces and cut to the inside edge of the drawn lines. This also gives a margin for the foil.

Fitting the pieces is still required though. Some people foil one piece and then fit the next to it before foiling it. This is probably the most accurate way of getting a close fit. However, I save up my cut pieces which I have fitted to the cartoon and foil them while watching TV. My cutting and fitting is normally accurate enough that I do not have to take the foil off pieces, grind and re-foil.

While doing this fitting you need to be aware that an additional small gap between pieces is required to allow the solder to join both the front and back of the panel. This forms an “I” beam for strength. The adhesive of the foil is not enough to make a lasting and strong panel. The solder joining the two sides will give the panel the strength to last for a long time.

Foiling Nuggets

Grinding of the edges of the nuggets is not required for foiling. Roughing up the surface helps some adhesives hold better, but it depends on the viscosity of the adhesive and the degree of "roughness" of the surface. The adhesive on copper foil sticks better to a smooth than a rough surface. Try sticking it both to glass and to fine sandpaper and see which is easier to scrape off, for example. You will find the foil easily comes off the sandpaper, which is the texture of the surface you leave when grinding.

So you do not need to grind. You may need to wash them with soap and water to remove any oil that may be on the surface to ensure a good contact, however. Just put the foil on the clean nuggets. Then put a bunch of the foiled nuggets in a plastic container and shake around until all the nuggets are nicely burnished.

Check each one to ensure they are fully burnished to the nugget. Smooth any lifted parts of the foil with a fid and they are ready for soldering.

Edges for Copper Foil

When doing a foil project which does not have a zinc or lead came frame, do you use a wider foil so it has a wider solder line? 

You do not need to use wider foil on the edges, but I have often done so to give the edge just as much "line value" as the internal beads. However this needs to be planned from the beginning. If you simply add a wider line on the outside, many times you will compromise the integrity of the design at the sides. You need to cut the glass a fraction larger to accommodate the thicker foil. Two millimeters added to the outside edge should be enough.

Foil not Sticking on Edge

An enquiry arrived the other day:
I’m working on another irregular shaped suncatcher and I have just completed the soldering. Now I've found one small section the copper foil is not sticking. How can I fix this?

The adhesive on copper foil tape is not a permanent one. It only sticks to the glass long enough to apply the solder to the foil. The heat of soldering often degrades the adhesive so much that it no longer sticks. What holds the solder down is the solder bead. So you probably do not have a full bead on the edge. Placing a bead on the edges of pieces is difficult but you can find a method here.

You can make the edge beading a bit easier by putting thin copper wire around the edge of the piece. This strengthens the whole piece. It allows you to attach a hanger without risk of pulling the whole suncatcher apart. It also allows you to form a bead on the edge more easily.

The bead formed on the edge curves around to the front and back faces allowing the solder to hold the copper tape more firmly to the glass.

Reinforcing Panel Lamp Shades

When constructing large or heavy lamp shades, reinforcement needs to be an integral consideration in the construction. With panel lamps the reinforcement is relatively simple – it can be along the seam lines. In fact, if you do not bevel your panel edges, it can be in the upper seam lines, as the solder filling the open joint will cover the wire. If the panels are bevelled, the wire can just go on the inside along the joint.

The wire should end at the edge of the bottom of the skirt so that it does not extend beyond, but will still be in contact with the edge reinforcement. The upper wire should extend beyond the top of the shade, so that it can be soldered to the vase cap. If there is not one, the wire should be dealt with as for the bottom, and there should be edge reinforcing.

The wire that is easiest to use is single strand copper or brass. It should be of a size to fit at the bottom of the “V” of each joining panel.

Also look at the ways of reinforcing the bottom edges of lamp shades

Glass Breaking While Soldering

Some report breaking pieces of glass while soldering. This may happen more on pieces that have big differences in width or taper to thin points. What is happening is that the glass is being heated too much locally in relation to the rest of the piece.

The solution is to solder at a steady pace. This allows the solder to cool without transferring so much heat to the glass as to break it. Some recommend that you do not rest your soldering iron on the foil while soldering. However it is the solder which is the heat sink, so the effort of holding the iron above the foil is not really necessary if you move at a reasonable pace.

This means that you do not stop with the iron on the seam. It is best to solder in one continuous movement along the seam, leaving an even bead behind. Sometimes the bead is not even. This may be because of wider parts to the seam, or inadequate flux, or many other reasons. Do not try to repair this before going on to the rest of the seam as this builds up heat in the adjoining glass. Since glass cannot dissipate heat well, the glass breaks when the temperature differential between the hot and cold parts of the glass is too great. Instead, complete the soldering of the seam before coming back to it. This gives you time to decide why the bead is not as good as you want it to be. It also gives time for the heat to reduce and even out through the piece of glass.

As you become experienced you will find a pace that suits the kind of bead on the joint that you want to achieve. If the seam is too flat, slow your pace or increase the rate at which add the solder to the iron. If the seam has too big a bead, increase your pace or reduce the rate at which you feed the solder. It is also possible to consider other methods of soldering.

You also need consider the usual problems relating to cleanliness and insufficient flux. Sometimes the soldering iron is not hot enough, but you should notice this early as the solder will not be melting at its usual rate and will be grainy in appearance.

Moving Pieces

To keep pieces from moving about as you solder them, use pins or nails to keep them in place. The best is to assemble the whole panel and then keep them in place with a frame or lots of nails/pins around the outside. This keeps pieces from moving and also keeps the panel to the original size.

The type of nail or pin will depend on the work board you are using. Softer boards allow push pins of various sorts to be used. Harder boards will need nails.

If you don’t like assembling the whole before soldering, you can confine the pieces you are currently soldering with nails/pins in the same fashion as for the whole panel.



It also helps to do a little tack soldering before the process of running a bead begins. A small amount of solder on the copper foil where pieces join will keep the pieces in exact alignment while you are running a bead.