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 alkaline solutions.  

Excess whiting (or chalk) has a carbonate chemistry, which 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.

Revised 2.1.25

Cutting concave curves

There are several methods that can be used to break out extreme inside curves. In all the cases you should retain a significant amount of glass around the edges of the curve. You should make this most difficult cut the first on the piece. If it fails, you may be able to move the glass a little and score again, without loosing too much glass.

To accomplish inside cuts by using the hand breaking method and/or pliers method, you must first score according to the cartoon line. Then you can make a series of concentric scores. Gently run the primary score line so any break does not run beyond this. Remove the graduated concentric scores in sequence.

In this example the glass is placed over the cartoon and scored directly over it.

You can also accomplish this type of cut by using the criss-cross pattern of score lines instead of concentric scores. First you must run the score of the curve to avoid the criss-cross lines from running beyond the curve. Then you begin to take out the little pieces from the waste area.


Another method is to score and run the curve (1), and then score a number of small crescents in the waste area, looking like fish scales or the fan type of paving seen in some European cities. Pull out each small crescent working toward the main curve (2,3,4).

Fitting Glass in Leading

Even though you think you have cut the glass exactly to size, it always seems that some adjustment is needed to areas of a piece to fit both into the lead came and be within the lines of the cartoon.

The temptation is to trim the glass to the amount of overlap of the cartoon line.

Note the extent of the overlap of piece #7 on the right.

In the above photo it would seem to be easy to just trim the straight line off the piece.  If you look carefully at the left side of the piece, you will see a gap between the glass and the lead came.  This means something more is happening than just being too large.  If you were to cut the glass down to fit within the cartoon line at this point you would find it too small in the end.

To find out what is going on underneath the lead came, you will see that I have made a line with a felt tip pen at the edge of the came.

When pulled out from under the came the line shows there is more glass under the came at the lower left than the middle left.  This indicates that the lower left needs to be adjusted rather than the right edge.

Groze or grind the glass to an even amount of glass between the felt tip line and the edge of the glass. This may have to be done several times to get the proper fit.  In this case I used the grinder because of the extreme texture of the glass.

This photo shows the glass fits at the bottom right, but needs more adjustment at the top right.  But it does fit under the came at the left side now. The amount of adjustment can be judged by marking the glass and grinding a portion away to fit.

An alternative example of the advantages of checking the glass is fully fitted within the came is shown here.

Here the blue piece shows it is slightly too large at the top.  The temptation is to refine the edges and reduce the size slightly.  Before doing that, it is advisable to check on how the glass is fitting into the came.  Again, run a felt tip marker along the edge of the came before pulling it out to adjust the size.

This shows there is a little bit of glass not broken off at the left side of the bottom tip.  Also, there is a larger space between edge and felt tip mark on the right than the left.

The first thing to do is to take off the excess glass on the lower left of the bottom tip and try the piece again.  That may be enough to allow the glass to fit into the came and match the cartoon.

The excess glass was ground away and a little taken from the bottom right side too.

This shows that just removing that small piece of glass has allowed the blue piece to fit correctly into the came and to fit the next piece of came to be placed without causing the panel to grow in size.

When a piece of glass is too large in leading, you need to check that it is fitted properly within the came, before adjusting the outer edges.  A method to do this accurately is described.

Adjusting Cut Running Pliers

Typical cut running pliers

Cut running pliers are very useful tools if used correctly.  The pliers must have the curve in a “frown” rather than a “smile” to operate properly.  The knurled screw at the top and the scored line on the top jaw help place the pliers the right way up. They must be placed directly in line with the score. They should be only a centimetre or so onto the glass.  Holding them at the end of the handles, apply gently increasing pressure until you hear a click or see the score running.  If it does not run completely, turn the glass around and apply the pliers to the other end of the score.

Use of the Adjustment Screw

It is important to make use of the adjustment screw to get the best from the pliers.  If this is not adjusted properly, it is possible to crush the glass, or at the other extreme, not run the score at all.

The jaws need to be adjusted for the thickness of the glass.  The method I use for this is to place the edge of the runners on a corner of the glass to be scored.  

Loosen the screw until the glass is gripped by the jaws.  

Gradually tighten the screw until it resists your gentle pressure on the handles.  This gives you the correct opening of the jaws for that piece of glass.

When the pliers are properly adjusted to the thickness of the glass, you will not crush the glass and it is easy to use the pliers without cushions.

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.

Strong Frames for Stained Glass Panels

Metals

Zinc is a popular material for framing copper foiled or leaded glass panels.  It is stronger than lead – up to eight times.  It gives a feeling solidity to the edges of the panel. 

However, it does have some disadvantages.  It is difficult to patina evenly and obtain the same colour as patinaed solder.  It resistance to progressive corrosion is weaker than lead. It requires special tools to fit around curves, making it best for rectangular panels.  It does need a saw to cut evenly, but so do a lot of the stronger metals.  A look at other options is worthwhile.

The strongest option is stainless steel.  This is difficult to cut and has special welding requirements, so is only useful in large and high corrosion installations.

Mild steel is widely available and cheap.  In certain circumstances – mainly small, thin profiles – it can be soldered.  The most secure joining is done with welding.  This requires equipment that stained-glass workers do not usually have.  However, there are a large number of metal workers that can to the work for you.

Brass is more expensive than mild steel.  It is an alloy of copper and tin and so can be soldered with the tools we normally use.  It is about half the strength of stainless steel, but three times the strength of zinc.  The tin content leads to a better patina result than zinc.

Copper is up to twice the strength of zinc, but the price fluctuates more than zinc.  It can be soldered. It requires different patina solutions than used for solder.

Aluminium is the same strength as zinc, but requires different joining methods as aluminium welding is a specialist activity.  Still, it will work on rectangular items with screws at overlapping joints.

More information on the relative strengths of various metals is given in a post on metal strengths.

Strengthening lead came

Lead is weaker than lead but can be bent to conform to curves and indentations for irregular perimeters.  If copper wire is incorporated and attached to the foiled glass, the soldering of the lead came to the joints at the intersections of the solder lines and the coper/came combination will provide greater strength than the zinc alone. 

When wanting to strengthen the perimeter of rectangular or shaped perimeter leaded panels, you can use 10mm “H” lead came soldered as usual to the whole piece as an alternative to soldering the wire to the panel.  Run the copper wire in the open edge of the “H”.  Pull the wire tight at the bottom and sweat solder at each corner.  Run the wire to the top on each side, where you can make a loop for attaching hanging wires and sweat solder the wires there too.  Then close the two leaves of the lead with a fid until they come together forming a single straight line.  If you want, a “U” or “C” edging came can be soldred to the outer edge of the "H" came to cover the line created by folding the leaves.

This post gives more detail about the process of incorporating copper into the perimeter of a leaded panel.

Melting Points of Solders

Common solders for stained glass are mixtures of tin and lead, respectively:

• 63/37: melts at 183°C (362°F)
• 60/40: melts between 183°C (362°F) and 188°C (376°F)
• 50/50: melts between 183°C (362°F) and 212°C (421°F)
• 40/60: melts between 183°C (362°F) and 234°C (454°F)
• lead-free solder (useful in jewellery, eating containers, and other environmental uses): melts between 118°C (245°F) and 220°C (428°F), depending on composition.

The 63/37 and 60/40 solders are most often used in copper foil work because of their smaller melting range. This allows the solder to set more quickly than the solders with higher lead content. They tend to give smoother beads also.

50/50 and 40/60 solders are more often used in leaded panel work. Their wider range of melting temperatures allows the solder to spread and become flat.

Other information on solders:

https://glasstips.blogspot.com/2015/07/physical-characteristics-of-solder.html

https://glasstips.blogspot.com/2018/02/lead-free-solder.html

https://glasstips.blogspot.com/2010/01/soldering-ingredients-and-methods.html

https://glasstips.blogspot.com/2015/07/lead-free-solder.html

https://glasstips.blogspot.com/2009/03/solder-alloys-1.html

https://glasstips.blogspot.com/2009/03/solder-alloys-2.html

Soldering Lead Came

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.

Soldering lead came The lead needs to be clean and bright to start with. If it's fairly new lead it should be solder-able without more than a scrubbing of the joints with a brass wire brush. However, if the lead is dull and oxidized, you should scrape the lead in the area to be soldered with a nail, the blade of a lead knife or other sharp edged tool until the bright metal is revealed.

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

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.  Once the whole panel is fluxed, you do not need to stop during the soldering process.

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

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 between the lead and the iron. In order to heat both pieces of lead you may have to rock the tip slightly to contact all leads being soldered. Take the solder away from the iron so it doesn't become attached to the joint. As soon as the solder spreads, lift the iron straight up. This process will take only a few seconds, much less than 5.

Example of smooth flat solder joints.

Avoid "painting" or dragging the iron across the joint. The object is to have a shiny, smooth, slightly rounded solder 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 forms a "pasty" joint.  Moving the iron around during the soldering of the joint often provides sharp points where the iron was moved quickly off the join. There should be no points sticking up from the solder joint. If a solder joint is not satisfactory you can re-flux and re-heat. Don't apply too much solder. It's easier to add more solder than to remove excess.

Soldering Irons and Rheostats

People often want to have variable temperatures for decorative soldering.

It is recommended to use a rheostat in circumstances where the soldering iron does not have an internal temperature control.

A rheostat is NOT a temperature controller.

Action of a Rheostat
A rheostat actually reduces the power supplied to the iron, thereby making it take longer to heat or re-heat after a period of soldering. Without a rheostat, if an iron is left idle, it will eventually reach its maximum temperature. This is usually too hot for soldering lead, but OK for joining other metals. With a rheostat, if an iron is left idle with the rheostat set to (say) '6', it will still reach its maximum temperature but very much slower than the one without a rheostat.

Action of a Temperature Controlled Iron
Temperature controlled soldering irons attempt to maintain a set temperature. This is controlled by the combination of the microchip in the iron and the tip. So to adjust your temperatures all you need is a few different tips. For example, a number 7 tip lets your iron heat to 700F degrees. For decorative soldering your need tips of lower temperatures, usually a number 6 or 600F degree is enough of a reduction for most decorative stuff. A number 8 tip (800F) will let you work at a higher temperature if you work quickly.

Differences in Soldering Speed
Using an iron without a rheostat, provided you work relatively quickly, you will probably be able to solder all the joints in a small or medium panel without stopping to let the iron 'catch up'. In this case the temperature is controlled by the heating power of the iron balanced by the cooling effect of making the soldered joints.Using an iron with a rheostat, you will need to slow down a little if you are to do that same panel without stopping to let the iron re-heat. In this case the temperature of the iron is controlled by the (reduced) heating power of the iron balanced by the same cooling effect of making the soldered joints.This difference is caused by the fact that a temperature-controlled iron, if it is left idle, it will quickly reach its maximum operating temperature - just as quickly as an un-controlled iron of the same power. When you start soldering, the cooling effect will trigger the temperature controller to provide full power until the operating temperature is reached again.

Advantages of a Temperature Controlled Iron
You can buy an iron (not temperature controlled) and a rheostat but buying tips for the temperature controlled iron is cheaper. The big advantage of the temperature-controlled iron is that you know it will never get too hot for the work you are doing, and that it truly provides that 100 watts (or whatever) power to keep it hot even when you are soldering at top speed.

Choosing a Soldering Iron

The iron used to solder must be of a high enough wattage to readily melt the solder and be able to reheat fast enough to maintain the necessary melting temperature. The tip can't be so small it can't maintain the heat nor so big it covers more area than wanted.

For example a 75 or 80 watt iron is sufficient to begin soldering with, but it will continue to get hotter, as it has no temperature control. An iron of this type should be used with a rheostat in order to prevent overheating while it is idling.

Most temperature controlled irons seem to be produced in 100 watts or higher. These internally temperature controlled irons maintain a constant temperature. They are normally supplied with a 700F° bit (number 7) and is sufficient to melt the solder without long recovery times. You can obtain bits of different temperature ratings, commonly 800F° and 600F°. You can also several sizes of tips for different detail of work.

  For volume work you can obtain temperature controlled irons of 200 watts and more.

It is also possible to obtain a Japanese made soldering iron with the rheostat built into the handle.

Structural Reinforcement

Leaded light panels often require additional support against wind pressure or vibration. Whether this is needed depends on the size and location, e.g. if in a door or a ventilating window that is constantly being opened and shut.  Large leaded glass windows need some bracing against the force of wind and rain. This can be achieved by using one of the following supports:

• Saddle Bar
• Reinforcing Bar (Rebar)
• Steel Core or Steels
• Zinc Section

Saddle Bars are the strongest method of support and are used in large external windows for preventing panels from bowing inwards. They resist wind pressure in exposed situations. Saddle bars form part of the latteral support structure of the window. These bars are attached to the panel with copper or lead ties.  These ties are soldered to solder joints across the narrow width of the panels.  The bars are fixed to the perimeter of the opening either by the mouldings or by being inserted into holes in the frame. The sides of the opening provide the ancor points for the bar.  The panel is fixed to the bar by twisting the ties around it.

A saddle bar fixed in position at the side and the ties being twisted around the bar.

Sometimes the opening is divided by sideways "T" bars.  Generally the leg of the "T" faces outwards and the panel is set onto the ledge formed by the leg of the "T".  This leg often has a series of holes drilled in the leg, for pins to be inserted to hold the panel in place until the sealant has cured.

An example of "T" bars being used on a small side opening window

Rebar is another external support.  It generally is a zinc coated steel strap about 2mm by 10mm and asl long as needed to cross the panel.  This tends to be soldered directly to the panel at the solder joints either on the inside or outside. One advantage of this material is that it can be bent to conform to the lead lines of the panel.  In consequence it is not as stiff as saddle bars are.

Steel core
Steel cores take two forms - either steel-cored lead or steel strips fitted into the lead cames when leading.  The steel cored lead came is less available nowadays.  They are mainly used in domestic glazing where support is required particularly in leaded lights with diamond panes when they are inserted in continuous diagonal leads. The steel cores are not adaptable to significant curves.

Steel cored lead came cut away to show the steel core

Zinc
Zinc section came is often used to frame a panel that is not glazed into a window or frame. It has been used in the past for both straight and curved lines.  Using it for curves requires a came bending machine to give good, regular curves.  It gives a panel strength for ease of handling, but does not resist sagging or bowing at the centre.  The other disadvantage of zinc is that it corrodes much faster than lead.

Image showing a variety of zinc came

Lead Light Cement

You can make your own lead light cement as the materials are fairly common and safe to use.  I have altered the original recipe through experience.  Too much of mineral spirits dries out the mix so quickly that the linseed oil cracks early in its life.  This results in the possibility of water leaking through the cracked cement.  One third or less of the dryer (mineral spirits) reduces the chance of too rapid drying.  I no longer use a drier at all.  This is my modified recipe.

Recipe
7 parts whiting/chalk
2 parts boiled linseed oil
(measured by volume)
1-2 Tablespoons colorant
This can be lamp black (carbon), black poster paint, concrete colorant powders, or black oil paint in sufficient quantity to give a black or dark gray colour to the otherwise off-white colour of the whiting and linseed oil.  

Do not use water based colorants, such as acrylic paint.  This does not mix with the linseed oil. Instead it forms a collodial mixture that interrupts the formation of the long linseed molecular chains that make it so good as a long term sealant.

The mixed leaded light cement

Method
Add the whiting (reserving about one quarter) to the linseed oil. Mix this well, by hand or with a domestic mixer capable of mixing bread dough. When these are mixed thoroughly, check the consistency. It should be like molasses on a cold morning - barely fluid.  At this point, add the colorant, so you will know the current colour and can adjust to make it darker.

Add more whiting as required to get the consistency you want. Experiment a little to find what suits you best. If you have to deliver the panel quickly, for example, you need to increase the proportion of whiting to make it stiffer. 

Comment
You should make only what you will be using on the current project, as the whiting separates from the linseed oil and sinks to the bottom in only a few days. The commercial cements have emulsifiers to keep the whiting from settling and so extend the life of the product. Since making your own is cheap and quick to make, there is no saving in making a lot.


Lead light cement is a simple, inexpensive sealant for leaded glass that you can make for yourself.

Care of Soldering Tips

Many soldering stations come with a sponge which, when wet, is used to wipe the iron's tip clean. A small amount of fresh solder is usually then applied to the clean tip in a process called tinning.

The copper that forms the heat-conducting bulk of the soldering iron's tip will dissolve into molten solder, slowly eroding the tip. As a result of this, most soldering iron tips are plated to resist wearing down under use. To avoid damaging the plating, abrasives such as sand paper or steel wire brushes should not be used to clean them. Tips without this plating or where the plating has been broken-through may need to be periodically sanded or filed to keep them smooth.

a common block form of sal ammoniac

To avoid using abrasives, cleaning with sal ammoniac is recommended. This comes in a block. You rub the soldering iron bit on the surface. As the surface becomes hot, it begins the cleaning process, noted by the smoke rising from the block. When the block under the bit becomes clear, the bit will be clean and can be tinned as above. If this is done at the end of each session of soldering, the bit will last and will be ready for soldering immediately when you next need to use it.

Other posts on maintenance are:
https://glasstips.blogspot.com/2008/08/care-of-your-soldering-iron-tip.html

https://glasstips.blogspot.com/2019/11/soldering-iron-maintenance.html

Pricing, 1 - Establishing the Cost

Pricing your work is necessary to get a fair return for your effort and to make an income.

Establishing the Cost

The first step is to calculate the amount it costs to run your business. Prepare a summary of annual outgoings including:

• Studio/workspace (or as a proportion of the house that you use for a home studio)
• Administration costs
• Equipment & loans
• Packaging
• Marketing materials
• Advertising
• Incidental expenses
• Income tax & social security payments
• Insurance for public liability, materials, equipment, and employment
• Depreciation (cost to replace things you are reliant on). The amount or proportion varies according to jurisdiction.

You will need to make some guesses about the amounts and that is OK. The value you put on some of the things above may be “zero”, but still need to be considered. All these are considered to be the overheads of your activity.


2. Step two is to calculate the time available to make your work over a year. If you are full time, start with 365 days and then subtract the weekends (104), holidays (say 10), administration time, and allow a contingency for sickness, etc.(say 10). That leaves you 241 days, less the administration time.  When you first start in business you are likely to spend 40% of your time on administration, but you should get more efficient and this time will reduce to around 30%.  So, even when fully up and running you will have about 169 days out of the 365 to spend on producing work - at best.  This means that you will have about 46% of the available time spent on production.

If you are working part time you need to do the calculations on the basis of the number of days you have available and do the subtractions and calculations as for a full time basis.  You may find your overheads are proportionally higher than fulll time, as these costs continue accrue whether you are in the studio or not.

Then do the calculation:

Overheads & personal salary (you do want to pay yourself - I insist!) divided by days available to work.

This enables you to fix a price for your time and gives you a daily rate from which you can calculate an hourly rate.


3. Step three is to estimate how long it takes you to do anything - preparation time, research, selling, marketing, packaging etc.

Add together the cost of materials and charge for the time it takes to make the item at the hourly rate you have calculated. This enables you to calculate a price for the item. Then look at how much the market will pay for your type of work.

Even if you know the market will not stand the full price, you should still do the calculations to find out the price that you should be trying to achieve.  If the price is unrealistic, you need to look at simplifying the item, or to consider different items.

All these calculations need regular reviewing.



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


Payment

Pricing, 2 - Pricing Structure

Creating a Pricing Structure

After calculating what you are going to charge, use the prices to create a pricing structure:

• Selling price to the public - recommended retail price
• Wholesale price/trade price
• Sale or return price
• Selling direct to the public

The selling price for the public should be the trade/wholesale price times two, plus tax. This means that the wholesale price is your bottom/lowest price that will give you a profit.

You should set your prices to realistically cover your costs, including time spent at an event, and know what you need to charge to make a profit. You charge double your wholesale price to cover your own costs of sales, such as packaging, stand hire, etc.

Do not undercut your other outlets, otherwise they will no longer want to sell your work.

Use selling to the public as an opportunity to test the market by exploring new products and new prices.


Selling to trade

The prices you offer to trade, i.e., your wholesale prices should cover your costs and provide some profit.

Galleries and shops have enormous overheads, which is why they put so much of a mark up on pieces, but remember they will be selling your work all of the time, so you can produce the work without interruption.

Before approaching wholesale or trade outlets you need to decide on:

• Minimum order quantities.
• Discount prices, and quantities to qualify.
• How much of your work they will need to make a good display (it is in both of your interests to display your work as well as possible).
• Consider charges for carriage or if you want to offer carriage free.
• Agree what the payment terms are – pro forma, payment on delivery or credit. If offering credit, ask for trade references.

Sale or Return

If you provide work on consignment (sale or return), make sure you know exactly what the terms are. Keep a close eye on the pieces, as there are risks that may or may not be covered by the seller

You do not want your work out for too long, so if it is not selling after 6 months it is time to move it. That means keeping records of where your work is and when it was placed.


Review your prices annually.




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


Payment

Leading - the First Glass Pieces

After establishing the perimeter lead cames, place the first glass piece into the corner formed by these cames. 

You only need to establish one vertical and one horizontal came to begin with. The other two will be placed at the conclusion of the leading.


Normally, you will be working from the lower left corner toward the upper right corner of the pattern if you are right-handed. The reverse is the case for left-handed people. 

Hold each piece of glass in place with some scrap lead and nail. The scrap lead will prevent the nail from chipping the glass. It's important all glass is held in place with nails so no shifting occurs while working in another area of the panel.

Fitting the rest of the glass to the cartoon is described here. 

Revised Feb 2020