Saturday, 29 November 2025

Quarry Glazing

 

For some reason that I have never learned, the regularly shaped pieces of glass that are leaded into a window are called quarries.  The derivation of the word relating to excavation comes from its middle English variant of medieval Latin quareria, from Old French quarriere, based on Latin quadrum 'a square'.   How it came to be applied to pieces of glass is unknown apparently.  However, in stained glass, "quarries" can relate to rectangles, diamonds, circles, etc., not only squares

These kinds of glazing are weak as there are long straight lines created with these designs. The best way of counteracting this weakness is to “weave” the lead joints within the panel combined with more frequent than usual glazing bars.

It may be wise to use a glazing bar at every second set of joints rather than merely consider the distance between bars.

See this post for designing quarries

Leading Tight Curves

 

Sometimes it can be difficult to get the lead came to conform to the curves of the glass, especially on compound curves.  There is a method to make the leading more accurate.

When leading tight inside curves, bend the came into a tighter curve than is needed for the glass. Then roll it into the glass. Finally, run your fid or stopping knife along the heart of the came to ensure it is firmly against the glass. All this helps the came to fit snugly into the curve.











Revised 1.1.25

Leading acute angles

 Most of us like flowing lines in leaded glass windows, but these often give very acute angles to be leaded up. One way is to avoid creating intersections by using passing cames.  

But, if the cartoon does not allow for passing cames in acute joints, you have to consider how to cut the came to butt well against the next came. The easiest, but most time-consuming method is as follows:

Determine what the length of the came must be to reach the end of the joint.

Mark your lead there.



Determine what the shortest part of the came will be at the joint and make a faint mark there too.

Cut the came at the first (longest) mark.

Use your lead dykes to cut the heart out of the lead, leaving only the flanges. This is done from the end to just beyond the faint mark you made to indicate the shortest part of the joint.



You then need to smooth the two flanges where the heart was. You can use a fid or your lead knife to draw over the rough interior of the flanges. This enables the flange to be inserted below the came already in place, or to slide the new came over the modified came.




You can trim the upper came flanges immediately to conform to the angle of the joint or do it when the whole panel is leaded. Make a mark with a nail or your lead knife along the edge of the un-modified came. Then raise the flange and use your lead dykes to cut the flange along the line. Fold the flange down to butt against the passing lead and it is ready to solder.







Friday, 28 November 2025

Radiating Lines

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.


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.
  • It also is a point of weakness as the multiple thin or tapering pieces of glass are liable to fracture. 
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.  It is the nature of glass, and sound design 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 what the solder has to  cover, and observe 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.



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. 

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

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

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


No one can teach an 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.





Assembly of Circles and Irregular Shapes

 Leading


Circles and ovals as well as irregular shapes need significant perimeter support as leading often involves sideways pressures to fit the lead to the pieces of glass. There are two main methods of support.

You can cut supporting pieces of glass to place around the perimeter. These need to be cut to the outside of the perimeter cut line. These supports must be in at least two or more pieces to enable the came to be put in place progressively. You then assemble the perimeter lead into it and continue to lead up as normal. The perimeter support can also be made from thin plywood or similar materials. This is useful if the shape is to be repeated.

A simple means of supporting irregular shapes while leading is to place a number of nails around the inside edge of the cut line. There need to be enough to support each piece of glass with at least two nails. So you may need to add more nails to the initial set up. Then build the panel without the perimeter leads. When the interior is assembled, put the perimeter came around the panel. Ensure the fully leaded panel fits within the dimensions of the opening. Then solder as normal.

Copper foil

The above methods can be used, but are often a bit heavy duty for copper foil processes. Instead of glass, timber or nails you can use more easily cut materials. Such things as stiff double walled cardboard, foam board etc., are suitable for light duty. You can cut the complete shape from these materials, but these lightweight materials are only good if no significant pressure is used in fitting the pieces in preparation for soldering.

If you are likely to repeat the shape and size, you can use plywood or similar materials. Build inside the shape and remove it when the whole is soldered on the first side.

Inserting Glass into the Came

If you have consistent difficulty in sliding the glass into the came, you should consider dressing the came before use. This difficulty most often occurs when using oval (or round)  came, which means the edge is slightly above the surface.  Dressing the came will help in easing the glass into the came channel.  It consists of running a fid or other hard material along each of the four flanges of the came. In doing this, you are pressing each flange in turn down against the bench or other smooth surface.





Dressing the cames gives a slight bevel or ramp for the glass to slide over the edge of the came and into the channel of the came. You can dress the whole length at once, or as you cut the pieces off from the main length. Dressing shorter pieces is less likely to bend the came.

Fitting the Glass to the Cartoon

Often you find that the next piece of glass does not fit properly. Possibly it rocks a bit in the came’s channel, or maybe it is simply just a little too big.  Wait! Don't adjust the piece just yet. It may not be the problem.

Checking

The first thing to do is to take the too-large piece of glass out and remove the came it fits into, to ensure the previous piece of glass is not too large. The glass should not overlap the cut line. If you have drawn your cut lines to 1.2mm (1/16”) you should see only the faintest line of paper between the glass and the dark cut line. 

If the glass seems too large, check that it is firmly in the channel of the previous came, as sometimes the glass catches on the edge of the came and does not go into the channel.


If that piece seems too large, the next check is to determine whether the apparently too large piece of glass really fits the cartoon cut lines. Place the glass inside the cut lines. You should see a faint line of paper between the glass and the cut line.


When you are sure both pieces of glass are the correct size, put the came back between them and check again. If the glass is still too large, check the length of the came. Make sure the came butting onto the came separating the glass is not too long. This is a common reason for lead panels to grow beyond their initial dimensions.


If the glass is the correct size and the butting cames are correct, replace the came. Put the too large piece of glass into the came and position it so it has the best fit to the next cut line. 


Do not be tempted to start reducing the glass at the visible portion.  After all, you cut it to the right size. It may be that the fit under the came is not very good.

To check use a felt tipped pen (Sharpie) to run along the edge of the came, marking the too-large piece of glass. Take it out and check on where the line is farthest from the edge of the glass. That is where you need to reduce the piece.


The nail points to the area that needs adjustment

When you have reduced the "high" spots on the glass so it fits under the came evenly along its length, you can begin to adjust the outer edge, if necessary.

Grozing

When leading, and often in copper foil, the easiest and quickest way to adjust the glass is to groze the glass to shape.  This is usually done with with combination grozing/breaking pliers.
Breaker-grozier pliers, or groziers, are pliers used by glaziers to break and finish glass in a controlled manner, a technique known as grozing. They are dual purpose pliers, with a flat jaw that is used for breaking out scores and a curved jaw that is used for grozing flares from the edge of broken glass. Both jaws are serrated for removing flares and tiny points of glass. Wikipedia

The technique is to use the pliers, curved sid up, with a rasping motion rather than gripping.  This removes small pieces of glass from the edge.  Sometimes it is necessary to turn the glass over and the the grozing from the bottom.  If larger pieces need to be removed, use the pliers curved side up still, grasp the glass and pull away.  This is easiest if a score is made in the glass at the correct line prior to grozing.

Occasionally, grozing is not as accurate as required and there must be resort to the grinder. 

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 the 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.