Radiating Lines

In designs for leaded and copper foiled glass it is important to avoid lines radiating from a single point. Some of these reasons are:

It is important to reduce the number of lines that meet in any design to avoid a big bright solder place in a panel.

Example of pattern with radiating lines

It makes for large solder blobs, especially on leaded glass panels, and therefore provides a focus where one may not be wanted or required.

The difference between the harder solder and softer lead came leads - over time - to cracks in the lead at the edge of the thick solder blob.

In leaded and copper foiled glass it is a point of weakness, as there are likely to be multiple thin or tapering pieces of glass that are liable to fracture early in the life of the panel.

Methods of Avoiding

This umbrella image avoids long narrow pieces by having the ribs and supports crossing to make short narrow pieces

Narrow tapering pieces can be compensated for by making the narrow parts shorter than the wider parts of the taper – although this does add to the density of lead and solder around the termination point. There is a difficulty in adapting single radiating points in a drawing to the practicalities of the medium of glass. Examination of older panels (in either technique) will show some of the problems of thin tapering pieces. It is obvious in older windows, especially in the Victorian Era, when tapered pieces where in their glory. Almost always, the tips are broken. It is the nature of glass, and goes back to knowing how the medium will react to the conditions you create.

The central circle avoids joining all the radiating lines at one point

Good design will avoid multiple radiating pieces from a single point of origin.

It is not possible to make a neat termination by joining half a dozen tapers at one point. The finished piece will not look like it did when it was drawn out with a pencil. You can pencil in a termination with six points, ending at one point and it may look good, but when you draw the design with the width of the led or foil will show the clumsy nature of the design with a large termination point.

As you can see, the answer starts with the design, before you cut and foil, or fit the came to the glass. Art is not about the physical placement of what you see in your mind, as much as it is about the "illusion" you are creating that you want others to see. That starts with the design, and avoiding something that you know is going to give you a problem.

It is not possible to make a neat termination by joining half a dozen tapers at one point. The finished piece will not look like it did when it was drawn out with a pencil. 

Example of a design that will present difficulties at the centre

You can pencil in a termination with six points, ending at one point and it may look good, but when you draw the design with the width of the led or foil will show the clumsy nature of the design with a large termination point. As you can see, the answer starts with the design, before you cut and foil, or fit the came to the glass. Art is not about the physical placement of what you see in your mind, as much as it is about the "illusion" you are creating that you want others to see. That starts with the design, and avoiding something that you know is going to give you a problem.

Overlapping Joints

Overlapping Joints in paneled windows

In many installations of tall windows, such as churches or tall sidelights, there is a requirement for handling and transport that the window be built in panels, each of which sit on top of the other. There are some considerations about the design and installation of such windows.

The design has to allow for the additional thickness of at least two hearts at the joins of the panels.

The leaves of the upper leads should always overlap the lower leads to be able to shed water from the rain so it does not migrate inside.

There should be wide heart “H” leads on the bottom of each panel. These should be 12mm or 16mm wide heart flat leads on all except the bottom panel where the normal 5mm heart can be used.  The wide heart lead allows easy placing of the upper panel onto the lower one.  It is possible to open the leads of a standard heart lead, but it is much easier to use a wide heart lead.

The top leads on each panel should be flat leads of 10mm or “U” lead. This is largely preference. If you use “H” leads at the top, you should fold the leaves over, or cut them off, depending on the allowance in the design.

The openings should have glazing or saddle bars placed at the levels where the panels join. These need to be tied to the panels with tie wires soldered onto the panels. The ties on the panels should be soldered so that the ties on the bottom of the top panel point downwards, and the ties on the top of the bottom panels point upwards.  It is important that the soldering of the tie wire on the bottom panel is very flat and low enough to avoid interfering with the flange of the upper panel and to allow the easy setting of the top panel over the joint. It is also worthwhile to put a loop in the soldered end of the tie wires so they do not pull out of the solder joint.

Once you are certain of a good fit, set the upper panel down onto the lower one.  Dress down the opened flanges of the upper panel over the lower one.  Then draw the wires from the upper panel down behind the saddle bar, the lower wires up behind the saddle bar, fold over them over the saddle bar, twist firmly.  Cut the ends to uniform lengths and fold back the twist up and over the bar.  This secures the panels, draws the two panels together and provides lateral support to the window.

It is not necessary to putty the joint of the panels, as the flange of the upper lead is sufficient with a little dressing of the flanges flat to the lower panel to avoid any ingress of water.

Radiating Lines

In leaded glass designs it is important to avoid lines radiating from a single point.

Good design will avoid multiple radiating pieces from a single point of origin.

Among the reasons for avoiding radiating lines are:

• It is important to reduce the number of lines that meet in any design to avoid the big bright solder place in a panel.
• It makes for large solder blobs, especially on leaded glass panels, and therefore provides a focus where one may not be wanted or required.
• It also is a point of weakness as the multiple thin or tapering pieces of glass are liable to fracture. 
• Also the difference between the harder solder and softer lead came leads - over time - to cracks in the lead at the edge of the thick solder blob.

There is a difficulty in adapting single radiating points in a drawing to the practicalities of the medium of glass. Examination of older panels (in either copper foil or leaded technique) will show up some of the problems of thin tapering pieces, especially in the Victorian era where tapered pieces where in their glory. Almost always, there will be broken tips. They seemed to compensate for tip stress by making the pieces with narrow tapers smaller than some of the other wider pieces. Even then, there are a lot of broken ones seen. It is the nature of glass, and goes back to knowing how the glass will react to the conditions you create.

Methods of avoiding tapering pieces lie in the design.

You can't use long tapered pieces in larger panels, without modification for the structural reasons outlined above.

Also you can't make a neat termination by joining half a dozen tapers at one point. Your piece will not look exactly what it looks like when you drew it out with a pencil. You can pencil in a termination with six points, ending at one point and it may look good, but try drawing it in with a felt tip pen almost 6mm wide, which shows for what the solder has to  cover, and see what that point looks like then. For copper foil a 2-3mm wide line will demonstrate what will be seen after soldering. You may not be pleased with the large blob at the termination.

No one can teach one easy fix for everything you will encounter, so the answer starts with the design, before you cut and foil, or fit the came to the glass. Art is not about the physical placement of what you see in your mind, as much as it is about the "illusion" you are creating that you want others to see. That starts with the design, and avoiding incorporating something that you know is going to give you a problem. 

Mitred Corners

There are various ways to determine where and at what angle to cut the lead came, especially for panels with more than four corners. But the most common is a four cornered panel. The following method works for that circumstance very well.

My preference is to use the battens surrounding the cartoon as a guide for the placing of the mitres on the first two cames. The battens are placed around the cartoon to suit the came width. The vertical came is placed in contact with the bottom came.

A short piece of came – ca. 50 mm – is placed on the external cartoon line almost in contact with the vertical lead. A second short piece is placed on top of the short piece and extended over the top of the side lead.

Mark the lead lightly with a nail or pencil. Cut the angle from the inside to the outside corner. This will form a 45 degree angle.

You can do the same for the bottom came, by removing the vertical came for the time being and doing the same operation on the horizontal came. Then they can be place back together for the next operation.

The finished mitre

To determine the length of the came which is already mitred on one end, put the came in place on the cartoon.

Then place a short piece of lead on the cut line which is at right angles to the came to be measured. Then place a short piece over the two cames as for the first mitre cut.

A nail or other pointed implement is used to scratch a line on each side of the overlapping lead. When this overlapping lead is removed, a diagonal is drawn from the inside mark to the outside mark. Cut along this diagonal.

Ready for cutting

There are other methods for panels with more than four right angles.

Starting

“Where should I start cutting the glass from the inside or outside of the cartoon?”

Once the colour selections are made, you can start the cutting in what ever order suits you. Some cut colour by colour. Others cut the glass in the order that fits together. This usually means the main image is cut first and the pieces laid up on a glass easel to determine their interactions. When satisfied, the background or in-fill pieces are cut and fitted.

“Where should I start building a panel?”

When starting the assembly, begin at a lower corner. Whether left or right will depend on whether you are right or left handed and the way the panel fits together. Although sometimes it can be easiest to build from the top toward the bottom. Starting in a corner, together with battens or supports for the outer edge  will keep everything in place as you work.

When working on an oval or circle, you can use a multiplicity of nails around the outside edge to hold the glass pieces. An alternative is to cut the curve into a piece or pieces of float glass and fix this to the work board to hold the glass. If you do this use the outside of the cutline so that there is space for the heart of the perimeter lead.

Lead knives

The advantage of lead knives over lead dykes are that a wider variety of angles can be made with the knife. There are a number of varieties of lead knives - ranging from adapted paint scrapers to specially made sophisticated tools.

The technique in using a knife is to wiggle or rock the blade with some moderate pressure down through the lead came. Excessive pressure will twist the came rather than cut it cleanly and squarely. When you find the effort or time required to cut through the came has increased, it is time to sharpen the blade. The sharpening angle should be very acute. You can use a fine oil stone or wet and dry sand paper to hone the cutting edge. You can also use a little bit of wax or soap on the blade to ease its passage through the came.

The most simple knife is a stiff paint scraper. The blade should be of good steel so that it takes and retains the sharpening that is needed from time to time. This blade works best by wiggling through the came.

Another style of lead knife has a curved blade. This has a number of variations. This knife works both by wiggling and by rocking.

Experience and personal preference will determine which style you settle on. The important elements are to make sure it is made from good steel and that it fits your hand comfortably.

You can add a metal end to the handle to provide a tool with more uses, especially as a hammer to put the nails into the board, or to snug up wooden borders, sometimes even gently tap the glass into place.

Also look at the use of lead dykes.

Squaring Panels

When building leaded glass panels to be placed in existing wooden frames, you need to make sure the panel is as square as the opening in the frame. The first requirement is to make sure your cartoon is squared, or has right angles at each corner.

I use a “roofing iron” as it is called in the UK. It is a steel tool about 600mm on one side and 400mm on the other. Its original use was to work out the pitch of roofs and check the same pitch was maintained all along the building. The first important thing – now that all roof trusses seem to be prefabricated – is that they still are in production. The second thing is that they all have a fixed right angle.

Using this roofing iron will ensure your corners on the cartoon are right angles. This helps in the drawing of the cartoon as you only need set the iron on the base line and draw the verticals without having to measure the width higher up the cartoon. Of course you should check that the width is still correct at the top, just in case there has been a slip.

Then you have to stick to the cartoon.

When you are setting the battens to ensure the sides are held where you want them while you continue with the leading, the roofing iron again will ensure that you have placed the battens at right angles. You choose which line is to be your base, and nail or screw it into place. Ensure it is exactly parallel to your cut line and then align one side of the iron against it. Place the other batten snugly along the length of the other leg of the iron and you know you have a right angle.

When you are completed leading, but before soldering you can check on the accuracy of the angles by using the roofing iron again at each corner to check on the “squareness” of the whole panel. If the panel is out of square, you can tap on the battens not yet nailed/screwed in place to ease it all back into “square”

Leading Nuggets

To use nuggets in leaded glass panels, just wrap the came round the nugget. If the came leaves are oval, it works better than the flat. If the nugget is thick and does not want to fit securely in the channel, you can also use a fid to open up the top leaf of the came.

There also is a technique to cut the came to give a smooth curve given here.

Growing Panels

What can be done to keep leaded glass panels from growing beyond their original cartoon lines?

I find that most people, who are not used to lead came, cut the crossing pieces too long so the whole panel grows. Each piece of came that is a fraction too long pushes the passing came out, making the glass apparently too large. You can and should make sure that you have pressed the came snugly against the glass. If the next piece of glass you place goes over the line allocated to it, something is wrong with the previous piece. Undo the came and check the size of the glass against the cartoon. If the glass fits inside the lines allocated, the problem is the way you have fitted the came to it.

Another check you can do is to run a felt tip pen at the side of the came onto the glass. Take the glass out and examine the space between the line and the edge of the glass. This will tell you where the glass and came are not fitting equally. A narrow space does not immediately mean the glass is too large, it may mean the calme is not tucked against the glass properly. So check that first, before any grinding.

Nails, push pins or other things that you can push into the work board will keep things stable. If you are working with a rectangle you can use wood battens. If not, multiple close spacing of nails will help. Also you could cut a piece of glass into a shape that will hold the outside of the panel.

Weaving in Leaded Glass

"Weaving" is only easily and fully done where there is a grid. The example below shows a restoration project where the main part of the panel is a grid.

This image shows the starting of the weaving. A short lead covering only one quarry has been placed horizontally - although you can start with a short vertical, both are fine. The next lead is vertical and covers two of the quarries. As you can see here the two quarries at the right are ready for the longer horizontal to be placed.




You proceed in this fashion - alternating long and short leads throughout the grid area.

As you can see this builds up in a diagonal fashion with each vertical and horizontal line being interrupted after every second piece of glass.

If you look closely you can also see that these leads are being tucked. This is easier with leads of 7mm and greater than of 6mm and less.

This method of leading gets its name from the similarity to representations of weaving in illustrations where a broken line represents the thread or reed going under another. Its purpose is to avoid hinges and so strengthen the whole panel. This avoidance of hinges makes the turning of the panel during soldering and cementing much easier.

Of course, you must remember that the glass is the strongest part of the panel.

Butting of leads

Lead came is normally cut to meet up against the adjoining cames. This provides a neat joint that will carry the solder without needing to fill gaps. The easiest joints to make are those at right angles. You can measure or estimate the amount that the came must be shorter than the glass, but it is easiest to use a piece of came the same size as will be passing the piece you are cutting (gauge came). You centre the gauge came on the cartoon cut line near the joint. Using your lead knife you can extend the line of the side of the gauge came to the piece you will be cutting. The mark you make with the lead knife can then be used to guide your cut of the came, as you take it away from the glass.

Those joints with angles have the came marked and cut in the same way as for right angles as the gauge came will give you the correct angle to cut.

Always remember when leading that you lead to the cartoon lines not to the glass. If the glass is short, use the cut line to place the gauge on, not against the glass. If the glass is too large, adjust its fit.

Soldering Lead Came

Historically soldering tips were copper, placed in braziers. One tip was used until it became too cool, when it was placed back in the brazier of charcoal and the next tip was used. Later gas irons were used and currently electric soldering irons are most commonly used.

The lead needs to be clean and bright to enable the solder to stick to it. If it's fairly new lead it may be solderable without further preparation. However, if the lead is dull and oxidized, you should scrape the lead in the area to be soldered with the blade of a lead knife.

Then apply the flux.

The iron is held over-handed (as you would a bread knife) in order to get the handle low enough to have the tip flat on the lead. You can allow the weight of the iron to press gently against the joint to transfer the heat into the lead or foil.

The solder is fed to the iron tip so as to melt an approximately five millimetre long piece of blowpipe solder.  Move the solder away as soon as it is melted, so it doesn't become attached. As soon as you see the solder at the joint melt and spread, slowly lift the iron straight up.

This image represents the principle of soldering any metal, not just computer boards

Avoid "painting" or dragging the iron across the joint. The object is to have a shiny, smooth, slightly rounded solder joint. There should be no points sticking up from the solder joint. If a solder joint is not satisfactory you can re-flux and re-solder. Don't apply too much solder. It's easier to add more solder than to remove excess.

The most common concern is whether there is enough solder on the joint. Very little solder is required to stick the joints together. Often a securely soldered joint shows the ends of the cames. For cosmetic reasons it is usual to use enough solder to disguise the ends of the cames. It is not a structural requirement.

Trimming Lead Came on Site

There are a variety of reasons for the panel not fitting the opening easily. These can range from poor measurements through parallelogram, trapezoidal openings or irregular perimeters of the openings.

In the cases of irregular openings, you can trim the edge cames if you have made them 12mm (1/2”) or more wide. The quickest way of trimming cames to fit the opening is to use a rasp or “surform” tool. The open nature of the teeth, allows the lead to fall away. It is much quicker than using a lead knife, and it puts less pressure on the panel.

Silhouettes in Leaded Glass

There are also times when you may want to have a silhouette, you can cut it out of lead foil and solder it into place. This allows intricate shapes to be made when a dark representation of the shape is required. If the panel can be seen from both sides, the overlays should also be on both sides. This can be applied to copper foil too.

Representing Acute Angles in Leaded Glass

False lines are used in leaded glass where the design calls for an angle that cannot be cut into the glass. This includes right angles and even more acute angles. E.g., the petals of a fuschia flower. The design would call for an angle of about 60 degrees. This is impossible to achieve through cutting. So the glass is cut in a curve and the cames on the side and bottom of the petal have their hearts cut out so they overlap each other. The overlap is then trimmed to the shape of the outside of the petal. When soldered, the appearance is of the glass being cut at the angle required for the flower.

Lead Knife

Description
The lead knife is used to cut the lead cames. There are many kinds of lead knives on the market. They fall into two basic types – the curved blade and the straight blade.
This is a necessary tool because lead dikes can't achieve acutely angled cuts readily.

Use
The important things to remember are to lubricate the blade, to maintain the proper angle, and to keep the blade sharp.

The blade is lubricated by wiping it through beeswax. Beeswax is slightly sticky so it will adhere to the metal better than ordinary wax. This greatly increases the ease with which the knife will slip through the lead.

The proper angle is maintained by keeping the blade in a line between your eye, the handle, and the blade where it contacts the lead. To push the blade through the came, you need to wiggle the blade from side to side (for a straight edge) or to rock it (for a curved blade) as you apply downward pressure. Too much pressure in relation to the wiggling or rocking movement will cause the lead to be crushed. Too little movement, will make the cutting slow.

Additional use
The lead knife can also be useful in positioning the lead around the pieces of glass, usually by gently pushing on the heart of the lead.

Lead Dykes

Description
Lead dykes are used to cut the lead came when the angle to be cut is oblique. The cutting edge of the tool is flattened on one side and is very sharp. This is a tool where you get what you pay for. It should be spring loaded to return to the opened position readily. The jaws should move freely and easily and should be large enough to span 3/8" lead.

Use
The tool is held with the jaws pointing down with the flat side of the tool facing the side of the lead you want flat. The lead is held oriented as it will be used. The tool will be cutting into the sides of the lead strip, not from the top and bottom of the came. When cut and observed directly from the top, the upper came flange should be directly over the bottom flange. If one flange extends beyond the other, there will be a gap where the cames meet.

Observation
This is a tool that cuts square or nearly square angles on came quickly and neatly. It is not very good for angles. A lead knife is better there.

Cartooning for Acute Angles

When you are designing panels, you can prevent some leading difficulties. If you have shapes that join at acute angles, you can alter the design to make the leading simpler.

Say you have two balls touching. You can design the panel so the cut lines intersect or touch each other. This makes for extremely acute angles in the cutting of the cames. Two balls touching in the presentation drawing will not look the same if leaded that way.  So if you make the edges of the balls just a few millimetres separate, the cames will pass each other, just touching, and so have the appearance of the presentation drawing, rather than the appearance of overlapping.

You separate the lines by the thickness of the came you will be using for that area. If you are using 6mm came, the cut lines should be just less than that distance apart. This will allow the cames to go around each shape and the flanges of the came will just overlap. This makes for quick leading and a clean appearance.

Fids

Fids are multi-purpose tools either manufactured (such as the All Nova tool) or made by the user. These can be used to open came, to dress the flanges, to push the glass, clean the cement from the edges of the lead came, and to do multiple things that would otherwise hurt your fingers. 

They are traditionally made from wood and you can whittle one from a piece of hardwood in a few minutes, so you can have a number for various purposes. 

Kebab sticks are good for tight curves and points, but you should use picks with large diameter handles to avoid carpal tunnel problems and reduce the tiring effort of grasping a very small diameter stick.

Fixing the Final Perimeter Cames

When all interior leads are in place, the top edge came is cut to butt against the vertical side edge, using a small piece of lead the same size to act as a gauge. These edge cames should butt up to the came ends in the interior.

Place a narrow strip of wood against the top outside came and hold it in place with horseshoe nails. Check with a square or by measuring to be sure the just placed came is at right angles to the left side of the panel. Do the same with the other side.

If adjustment is necessary, firmly tap the wood batten with the hammer end of your lead knife to get it into position. Place nails to hold the cames in position and get ready to solder.