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.

Soldering lead came is different from soldering electronics or copper foil. For electronic soldering less heat is needed, cleanliness is all important, suitable flux is required, and the iron is held differently, among other things.

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 before adding the flux. 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, or glazing nail.

Then the flux can be applied.  Paste flux or tallow works best as neither flows in its cold state.  This means that you can flux the whole panel at one time without the liquid flowing away or drying.  And once the whole panel is fluxed, you do not need to stop during the soldering process.

an example of paste flux

Example of a tallow stick.  It has the appearance of a candle, but without the wick.

Example of the application of tallow to a joint

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.

Example of a gas powered soldering iron. The flat face of the soldering bolt is held in full contact with the joint.

The solder is fed to the iron tip in one of several ways.  

• One is to place the solder over the joint and melt a small amount off the solder stick and pause to allow the solder to heat the joint and bind the metal together.  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, lift the iron straight up.
• Another method is to apply the solder to the iron before placing the iron on the joint and allow the solder to run to the joint.
• A very fast way of soldering, which runs the risk of melting the lead, is to heat the joint and then apply the solder to the iron.  This ensures the joint is hot so the solder quickly attaches the metal together.

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

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.

An electric soldering 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. This will be a 15 to 20 degree elevation from the horizontal. Allow the weight of the soldering iron to do the work for you. 

Let it rest on the joint after you apply the solder.  Take the solder away from the iron and joint so it doesn't become attached to the joint.  As soon as the solder spreads from under the bit, lift the iron straight up. This process will take only a few seconds, and much less than 5.

Example of smooth flat solder joints.

Avoid "painting" or dragging the iron across the joint. Moving the iron and solder around does two things.  It makes for a weak joint as the solder does not have the chance to become stable and so a "pasty" joint is formed.   Moving the iron around during the soldering of the joint also provides sharp points where the iron was moved quickly off the join. There should be no points sticking up from the solder joint. 

The object is to have a shiny, smooth, slightly rounded solder joint. If a solder joint is not satisfactory you can re-flux and re-heat. Don't apply large amounts of solder - it's easier to add more solder than to remove excess.

Nails

 Glazing nails

Horseshoe nails are normally used to temporarily hold glass and lead in place while assembling the panel. The flat side of the nail goes against the lead. If the final lead is in place, try to put nails where there will be a solder joint. This will hide any "dings" in the lead. If no lead is yet in place, use a piece of scrap lead to protect the glass from chipping and to raise the glass to a common level before placing the nail. When pulling a nail, rock it in the narrow, side-to-side direction in order to prevent bending the tip.

Image credit: Peli Glass

An even more convenient nail is the round German nail which is hardened steel and sharply pointed. This nail can be started with one hand which is handy when your other hand is busy holding everything together. Use a twisting motion to pull the nail.

Revised 1.12.25

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.

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.