Thursday, 28 August 2008
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.
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, 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.
It is necessary to have clear terms and conditions established at the time of purchase. If you have put your terms on your invoice, you can enforce the conditions and take the customer to court.
Always invoice promptly. This is important for your cash flow and reduces the chances of payment problems.
Always keep good records of orders and invoices so you know what is overdue and when to chase for payment. A simple accounting software package will assist.
Maintain good communication and be professional. When you contact someone about an outstanding debt, be polite. However, do not allow them to walk over you. Be firm in your request for payment. Ask them to suggest a time scale for payment – normally people are committed to their own suggestions. But do not accept unreasonably long payment schedules.
More information is available from craftscotland.
It is vitally important to keep a customer database and to develop good communication channels with them.
Always remember that trade customers need you as much as you need them, so keep them in touch with news.
It is also advisable, to make sure you allow enough time to deliver orders. It is better to say it will be two weeks and deliver early than the reverse. If you do fall behind, keep in touch with customers. Also, remember it is acceptable to have a waiting list if necessary, as part of what the customer is buying is the exclusivity of your work. Always remember who or what else you may be reliant on, i.e., the weather or length of time for shipping.
If you are contacting new outlets or customers do no more than 10 at a time so you can control or monitor the process. If someone says no to your work ask why, as it is important to know for your future business.
If you are supplying, or want to supply, to different outlets in the same area negotiate with them. Consider customising work for different customers or offering different parts of a range.
Be consistent and professional in the way you manage your relationships with customers.
Listen to customer feedback and develop ways for customers to make suggestions, such as comment cards.
Keep in touch with people who have bought your work before.
More information is available from craftscotland.
- Details of your minimum orders
- Carriage/delivery - is it free or charged to the customer?
- What is the recommended retail price? It is useful to include this, as you will often be asked to provide a figure by shops.
- Any conditions about display or point of sale material (if you provide any)
- Credit terms
- What deposit is necessary - when a member of the public places an order always take a deposit or ask for full payment in advance.
- Details of any interest charges that you will charge on any outstanding debts.
- Once an order is placed, get the customer to sign it and make sure they are aware of the relevant terms and conditions.
More information is available from craftscotland.
After calculating what you are going to charge, use the prices to create a pricing structure:
- Selling price to the public
- 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.
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 ReturnIf 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 from craftscotland.
Establishing the CostThe first step is to calculate the amount it costs to run your business. Prepare a summary of annual outgoings including:
- Administration costs
- Equipment & loans
- Marketing materials
- Cost of living & expenses
- Income tax & social security payments
- Insurance for public liability, materials, equipment, and employment
- Depreciation (cost to replace things you are reliant on)
- Investment for future lifestyle
- Add in the things that make life worth living.
The value you put on some of the things above may be “zero”, but still need to be considered. These are considered the overheads.
2. Step two is to calculate the time available to make your work over a year. Start with 365 days and then subtract the weekends, holidays, administration time, and allow a contingency for sickness, etc. When you first start in business you are likely to spend 40% of your time on administration, but you should get more efficient and the administration time will reduce to around 30%.
Then do the calculation:
Overheads & personal salary 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. This enables you to calculate a price. 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. All these calculations need regular reviewing.
More information is available from craftscotland.
Wednesday, 27 August 2008
First, score the circle, making sure that you start and stop the score line at the same point.
Turn the glass over onto a piece of corrugated cardboard, or other surface with some give, with the score line face down. With your thumbs, press along the score line until you see the score line "run" progressively and completely around the circle. This prevents the relief scores you are going to make from running through the circle.
Turn the glass back over to the side on which you scored it. Score several lines perpendicular to the circle to the corners of the piece of glass. Gently open these scores by tapping with the ball of your cutter, or with your hands, pliers, or other tools. The the pieces should fall cleanly from the circle leaving you with no rough or jagged edges.
Tuesday, 26 August 2008
The first question you have to ask yourself is whether you should make such deep inside cuts or redesign the piece to avoid creating such fragile shapes.
OK. You have decided to go ahead with your plan in spite of good advice. Put your cartoon onto the turntable and the glass over it. If the glass is too dark or opalescent, make a template and mark the glass. Adjust the starting point, put one hand on the glass and cartoon, and turn the glass instead of yourself to get round the score with ease.
You still have the task of breaking out the glass from the score line. This is the subject of another tip.
Monday, 25 August 2008
Another method is to use the edge of the bench as a guide. With a small adjustable carpenter’s square, you hammer in nails at the predetermined width (plus half the thickness of the cutter head). Align the glass to the edge of the bench between the nails. Place a straight edge against the nails and score. This gives strips of the same width every time, but works best with strips of 10mm (3/8”) or more. This is illustrated in the processes section.
The thinner the strips are to be cut, the more important it is to make the scores and then divide the sheet in half - the two halves in half each - the 4 quarters in to halves, etc, until you are down to the piece that only needs to be divided in two.
Sunday, 24 August 2008
Cut running pliers are most useful until the last two thin strips are to be divided.
At that point use two breaking pliers to hold each side of the two pieces of glass. The noses of the pliers should almost touch on either side of the score line. Apply pressure in a downward pivoting motion to break the pieces apart.
Relieving scores made alongside curved and tapering pieces make the breaking more certain. A relieving score is one that is in addition to the primary score. This additional score will allow you to break the thin or tapering piece from the larger sheet safely, and then go on to break out the delicate piece.
The object is to always be breaking away less glass than is retained. The use of two breaking/grozing pliers, one on each side of the narrow pieces gives more even pressure than fingers or cut running pliers with wide jaws.
When breaking tapering pieces of glass you should normally grasp the thick end in fingers or pliers and run the score toward the thin end.
Use a cutting square or other non-slip straight edge to guide the cutter. You can push as in normal stained glass cutting, or you can draw the cutter toward you as glaziers do. In either case, the pressure needs to be even and the speed consistent.
When moving large scored sheets, avoid pulling the sheet by one end. The score may run suddenly and not always along the line. Instead, move the sheet with support on both sides of the score. After the glass is scored, you have choices about how to run the score.
One easy way to break off large pieces is to move the sheet so the scored line is just inside the edge of the bench. The biggest piece will be on the bench and the smaller piece in your hands. Give a quick, sharp downward push with both hands on the overhanging glass. This action will separate the piece from the main sheet. Having the glass score inside the bench edge gives you a place for the broken off piece to rest, rather than pivoting toward the floor.
Or you can slide the straight edge under the glass on one side of the score, and press firmly, but not sharply on each side of the score. The glass will break evenly along the score line. This is a more gentle method of breaking the glass. A variation on this is to place a couple of matchsticks or glass painting brushes at each end of the score and apply the pressure.
If the glass sheet is of a size that you can hold it in both hands with the score between, you can draw it off the bench, let it hang vertically, and bring your knee up briskly to hit the score line, and it will break easily. This is a showman’s way of breaking glass sheets when the score line is approximately centred on the sheet.
Cut running pliers often do not work very well for long straight scores on large sheets of glass. However, if you use this method, tapping at the start and at the end the score line before squeezing the running pliers will help the score to run the way you intend. This is sometimes the only way to achieve the break of the score.
It is important to keep these brushes free of hardened cement, as a brush containing pieces of hardened cement will scratch the leads rather than darken them. As soon as the polishing is finished, inspect the brush for little balls of cement. Rubbing the brush against a clean rough surface will clean it while the cement is “wet”. Also running the brush at an angle on the sharp edge of your work bench will clear some of the cement adhering to the bristles.
If the cement hardens, you can clean the brush by crushing the hard balls of cement with a pair of pliers. Or you can just get a new shoe polishing brush.
For scores with significant, but not necessarily equal, amounts of glass on each side of the score this is a quick simple approach to breaking glass. After scoring, raise one edge of the glass and put your fingers under the glass on each side of the score. Curl you fingers into your palm, and put your thumbs on top of the glass. Turn your wrists outward and the glass will break cleanly.
With practice, the initial part of a curved score can be run by applying light pressure. Then you can turn the glass around and run the score from the other end to the opened score. This avoids lots of tapping and gives clean edges to the cut glass. It is just as simple as using cut running pliers and avoids the flare often associated with using cut running pliers.
This technique works best with glass that has at least a couple of inches (ca. 50mm) each side of the score and on gently curved lines. For tight curves and narrow strips other methods need to be used.
If you have any dark gunk build up that won't come off on the sponge, rub the hot iron tip against a block of sal ammoniac until the block clears. If the dirt is difficult to remove with the sal ammoniac, use a brass wire brush to scrape the dirt off and then go back to the sal ammoniac block. When it is clean, add a touch of solder to re-tin the tip, and then wipe against your wet sponge.
Remember, all this is done while the iron is hot, so be careful.
Primary colours are three key colours - Red, Blue and Yellow. They cannot be made from any other colour.
If you mix equal amounts of the primary colours, you get the Secondary colours - Purple, Green and Orange.
Red + Yellow = Orange; Red + Blue = Purple; Blue + Yellow = Green
If you mix a primary with a secondary colour, in a ratio of 2:1, you get a Tertiary colour. Red-Orange, Blue-Green etc.
Cool versus hot
Look at a colour wheel and you will see the left hand side of the colours are 'warm' or 'hot' and the ones on the right are 'cool' or 'cold'. This is useful when you want to create a mood in a particular room or need to make your space cosier or lighter.
Neutrals are one of the easiest groups of colours, or non-colours to work with. They don't appear on the colour wheel and include Black, Grey, White and sometimes Brown and Beige. They all go together and can be layered and mixed and matched. No neutral colour will try to dominate over another.
An accent colour is a colour used in quite small quantities to lift or to add punch to a colour scheme. An accent colour should be in a complimentary colour. It works best if it's a bright, vibrant colour. Accent colours are perfect if you're scared of using strong colour - simply add a splash of an accent colour. Keep most of your piece in shades and variations of one single harmonious colour. Then pick out just a few objects in an accent colour.
To use clashing colours is thought to be a no-no in formal settings. But in more informal or vibrant settings they can look fantastic, if they are used carefully. If they are of equal tonal strength, you can mix them together. Don't stop at two, you could try three or four. But if one is paler or weaker than the rest it will get lost in the overall scheme.
- Calculate half the measurement of the longest line. Measuring from the end of the shortest line, mark off this amount on the longest line, top and bottom.
- Insert a pin at both these points.
- Place a piece of thread round one pin. Tie a knot in the thread at the far end of the longest line.
- Put a pencil inside the loop. Pull the thread taut and begin to draw the oval.
When using enamels within the painting, do not let any patina come in contact with the finished production. The patina will bleach out all the enamel colour. The patina will etch off the outer layer, either removing the shiny top layer of paint, or the delicate lines of detail work altogether. Copper patina takes a little of the paint off, but not nearly as badly as the black.
Instead, brush the panel with a natural bristle brush used for putty clean up, and polish.
Silver stains that have been properly held at the maturing temp, should withstand any patina application, as they have become "part of" the glass.
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.
Flux is a substance that is nearly inert at room temperature, but it becomes strongly reducing at elevated temperatures, preventing the formation of metal oxides. Secondarily, flux acts as a wetting agent in soldering processes for lead, copper and brass.
Without flux the solder does not firmly attach to the lead or copper foil and often forms sharp peaks.
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.
Use a soft brush to polish lead came. Don't pick out the cement until the polishing is done, as it provides the colour for darkening and polishing the lead and solder joints. The action with the polishing brush should be gentle and rapid, much like polishing shoes. If the shine does not come, you can use a very little stove blackening (carbon black mixed with a little oil) If you use a lot, you will have a big clean up job. A little stove blackening spreads a very long way.
Before turning the panel a final time, put down paper or cloth, to avoid scratching the solder joints while polishing the other side. The result should be shiny a black came and solder joints that does not come off the way a final buffing with stove blackening does.
Finally, pick out any remaining cement.
Rest horizontally with weather side down for traditional installations. If the panel is going into a double or secondary glazed unit, you may want to reverse this. The reason for having the smallest exposed cement line on the outside is to allow the water to run off the window with the minimum of area to collect. In a sealed unit or for secondary glazing, you may want to have the smallest amount of cement showing inward for appearances, as there is no weathering reason for the traditional method.
Rest for a day. Pick out the cement again. If the cement was stiff enough, there should be no need to do any more picking at the cement after this.
After the pushing the cement under the cames on both sides, flip the panel over and begin a firm rubbing to push cement into the gaps between the lead and glass. Sprinkle the used dust from the bench top over the panel and rub in all directions. This begins to set up the cement by helping to provide a stiff skin over the more fluid cement. Brush until the whiting is largely off the panel. Turn the panel and do the same for the second side. Several applications of whiting/sawdust are required to give a sufficiently thick skin to reduce the amount of spreading, leaking or weeping cement.
Once both sides have been done a couple of times, begin to concentrate the brush strokes along the lead lines rather than across. This will begin the cleaning phase and also begin to darken the came. Repeat this on the other side.
After a few turnings, most of the cement will be cleaned from around the leads. Don’t try to get all of it away, you will need that colour for polishing. The glass will be shining, and any felt tip marks you made on the glass will have gone too. Clean up the dust from the panel and bench in preparation for polishing.
Cementing panels is as old as leaded glass - about 1,000 years - so it is a time-proven process using simple materials. The object of cementing is to make a leaded panel weather/water tight and sturdy. It can be messy and dusty, so putting on an apron and a dust mask are a good idea.
Start on the side that is already facing up after soldering. This normally will be the rough side. This way you do not have to move the panel much until it has stiffened with the addition of the cement.
Cover all open bubbles, rough glass (waffle, ice, etc.) and all painted glass with masking tape. Put the tape over all the relevant areas of the panel, then use a sharp knife (X-acto, scalpel) to cut the tape at the edges of the came. The cement will go under the came, but not into the texture of the glass. This will make the clean up of the glass much easier after cementing.
With the panel on the bench, put a dollop of cement on the glass and rub it in all directions with a stiff, but not hard, bristle brush to force it under the lead. When the cement has been pushed under all the cames, but with a slope of cement showing, spread a little fresh whiting or sawdust on the panel and gently push it against the cement under the leads. This begins the setting process and keeps the spreading cement from sticking hard to the glass or bench.
Turn the panel over to cement the second side the same way as the first. If the panel is a large one, you may want to use a board to support it in these early turning stages. No gaps can be tolerated in the cementing. Cement leaking out the other side is good evidence that all the gaps between the glass and the came are filled. Again, after cementing, sprinkle new whiting/sawdust over the second cemented side and rub it gently into the exposed cement.
Cleaning the brushes is very simple. The action of rubbing the cement under the leads with whiting causes a natural cleaning action to take place. As the bristles flex back and forward over the came, the cement is forced upward toward the handle, and then outward between the bristle bunches. Only a little effort is required to finish the cleaning: push a rounded stick between the bunches to move out the remaining cement. You now have a clean brush for the next job.
The alternative is keeping the brush in water, but this presents the problem of getting rid of the water (oil and water do not mix) before beginning to cement. As the water will emulsify with the linseed oil, it will be carried into the putty, leaving gaps in the cement when the water eventually evaporates. The cement will eventually harden, even though in water, as linseed oil cures by creating an organic polymer through oxidisation. It can also rot the wood handles.
Keeping the brush in mineral spirits does keep the brush flexible but requires drying/evaporating the spirit before beginning the cementing to avoid the residue of the spirit creating cement that is too thin at the start. This can be a really messy problem!
If you choose the “dry” method, it is important to keep the brushes free of hardened cement as it will scratch the leads badly, if not the glass also. Most brushes will only last 5-10 uses, and as they are not expensive, should be easy to throw away.
7 parts whiting/chalk
1 part boiled linseed oil
1 part mineral spirits (turpentine or other)
(All of the above measured by volume)
1-2 Tablespoons lamp black or other colorant – black poster paint, acrylic paint or oil paint
Add the whiting (reserving about one quarter) to the linseed oil and mineral spirits. 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 colourant, 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 mineral spirit. The mineral spirit evaporates relatively quickly, leaving a more rapidly stiff cement.
CommentYou should make only what you will be using on the current project, as the whiting separates from the linseed oil and spirit relatively quickly. 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.
- 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 sagging. They also resist wind pressure in exposed situations. Saddle bars form part of the support structure of the window. These bars, often in the shape of a sideways “T” (and so sometimes called T-bars) are fixed to the perimeter of the opening and so transfer the weight of the glass to the sides of the opening.
Rebar is used to prevent a panel from bowing but do not give support where multiple panels are assembled. Saddle bars are preferable in these circumstances. Rebars are normally round bars that are attached to the panels by twisting copper ties that are soldered to the panels.
Steel core takes two forms - either steel-cored lead or steel strips fitted in the lead cames when leading. They are mainly used in domestic glazing where support is required particularly in leaded lights with diamond panes when they are inserted in the continuous diagonal leads.
Zinc section is often used to frame a panel that is not glazed into a window or frame. It gives a panel strength for ease of handling, but does not resist sagging or bowing.
You place the end of the came into the vice so that the came appears at the back of the vice. Give the top of the vice a firm tap with your pliers to set the teeth into the came. Grasp the other end of the came with the pliers, and put one foot behind you to brace yourself if the came does slip out of the vice. Draw the came toward yourself until you can see the lead is straight and any kinks have straightened.
Take the came out of the vice and keep it straight. You transport it by grasping each end and keep the came under tension until you get it to the destination. It is often easiest to cut the full length in half before moving it, as it will not then be longer than your arms can stretch.
Remember, this process is to straighten the came to give pleasing lines in the leaded panel. It is not stretching the lead. Stretching the came can weaken the lead.
To ensure the came is tucked snugly against the glass, you use a fid of firm material (wood or plastic, for example) to press against the heart of the lead. You can press directly toward the glass, or make multiple passes along the length of the came to ensure the heart is touching the glass all along its length.
You should avoid steel tools, because you may cut the lead, and if the blade is long you will not find it easy to fit along all of the curves.
Draw the circle of appropriate diameter on the turntable with a compass. Place the glass on top of the turntable, and position your cutter above the drawn circle. Press on the cutter with one hand and turn the glass with the other.
Steady your hand with the cutter by keeping your elbow tight against your side. This enables you to make a very good, if not perfect, circle without buying an expensive small circle cutter.
If the glass is too dark or opalescent to see the line, make a template and put it onto the glass. Cut beside the template or use the template to mark the glass. Then place the marked glass on to the turntable and cut as with transparent glass.
You will not be able to run the score by turning the glass upside down and pressing as you can with larger circles. You will need to make a number of relieving cuts to the tangent of the circle and break them away one by one. Yes, this does leave a rough edge at various places around the circle, so grozing or grinding will be necessary.
The first step is to cut the came to the appropriate angle to meet the lead to which it is to be joined. However before presenting the cut came to the joint, one end is lightly tapped with a small hammer to slightly curve the end of the came. This allows it to slip inside the leaves of the came to which it will be soldered.
The came is then shaped to the glass as normal. However, rather than removing the came for the next cut, the came is cut to the length of the glass, often using the glass as a guide. This end is then supported on the lead knife and tapped with the hammer to curve the end, ready for tucking into the next piece of came. Care is required so that you don’t crush the came and break the glass, nor miss the came and hit the glass or your fingers. With practice, there are few accidents.
Tucking lead provides very accurate joints with no gaps for solder to fall through. Some argue it provides a stronger panel as the hearts of the jointed cames almost meet. The main immediate gain is quicker soldering.
Use oval or round came to reduce the kinking of the leaves of the came. As there is less material at the edges of the leaves of oval came, there is less kinking than on flat came, where the thickness of the leaves is constant.
Begin to form the lead round the circle, about half way. Then take the circle out of the came and cut, at a right angle to the length of the lead, at an angle from top to bottom. The degree of the angle is not important at this stage, only that you can repeat the angle – so it must be fairly shallow and natural for you.
Put the circle back into the came and continue to form the came round it until you meet the angled cut at the beginning. Again at right angles to the length of the came, cut a repeat of the angle.
This technique can be used for small ovals too.
Saturday, 23 August 2008
Start with a work board that is thick enough to be relatively rigid, but is easy to put nails into. Plywood is a good, but relatively expensive board. MDF is heavy and difficult to nail, so avoid it.
You can either have two permanent battens about 19mm (3/4") thick strips of wood attached at right angles to each other in one corner, or you can attach them to the board as required. The permanent placement means you do not have to check the accuracy of the right angle each time you use it, but it does not allow easy adjustment for smaller or larger pieces than the battens will accommodate. The temporary solution requires checking the right angle each time you use it, but it allows you to place the battens over the cartoon at the appropriate distance from the battens without cutting the cartoon or multiple checks of the accurate placement of the cartoon.
The battens should be attached to "base" board about 60mm (2 1/2") in from the edge to have a little work area to cut leads, etc. They need to be a little longer than the dimensions of the pattern you are assembling.
If you are putting the battens on top of the cartoon, you can use the cut lines to align your battens. Cut two short pieces of the came you are using for the edge. Centre their hearts on the cut line and butt the battens against them. Nail or screw the batten in place. Repeat for the other side.
If you are using permanently fixed battens, place the cartoon, which has been trimmed to the outside lead line on two sides, against the wood strips. Use some horseshoe nails to hold the pattern in place. Check to ensure the correct distance has been maintained between the battens and the cut lines on the cartoon. Adjust as necessary.
Here you are just beginning leading and some one asks you to repair their leaded glass window. But they don't want you to take the window out of the frame. They want you to do it in situ. There are some general guidelines on how to go about it:
- Gently remove the cement from under the came leaves. You can use most any kind of stiff blade. You don't have to get it all out at once. Just work round the whole piece of glass.
- With a sharp lead knife, cut diagonally into the solder joint until you are half way through.
- With a stiff blade gradually work the leaf of the came upwards. A stiff oyster-type knife (properly called a stopping knife) works really well.
- Continue to gently lift the leaves of the came until they stand vertical almost back to the heart. This obviously is much easier on thicker came than thinner. I will not try to do any less than 6mm, and that is difficult. It is also more difficult to do with half round came than with flat came.
- With grozing pliers gently lift the solder joints. Be careful of the surrounding glass, so that you don't have to replace more glass.
- If you haven't already now is the time to tape the broken glass together.
- Work out the cement between the came and the glass. This should provide you enough space to work the glass out.
- In some cases the glass won't come out in one - taped together - piece. Now is the time to take a rubbing of the opening so you know exactly where the leaves of the lead came are. It provides a pattern piece.
Smash the glass out. Wear safety glasses and gloves.
- If the glass has come out in one taped piece, use it as a pattern. You can trace round it with a felt tip pen and cut inside the lines. You can put it under the new glass and cut, using the edges as the cutting lines. You can also make a paper pattern from the glass.
- Insert the replacement glass into the opening. Most likely it will not fit in some places. See if the lead came leaves can be opened a little more. Also mark where the glass is too large. You can groze the glass, or if you are near a grinder, grind off the "high" spot.
- Now that the glass is in the opening, begin to gently smooth the came leaves toward the glass with your stopping/oyster knife. Start by only gently changing the angle of the leaf. Any large movement of the leaf will greatly deform it.
- If the solder joints are still standing up, take your stopping knife and gently tap the end of it with a hammer. The stopping knife should be parallel to the glass. Any hard hitting will tear the solder joint from the lead. (If you were doing this on a bench rather than on a vertical window, you could heat the solder joint and re-solder without all the tapping.)
- Push stiff cement coloured black under the leaves of the came from both sides if possible. Clean off excess. Polish with a soft brush.
If there are lots of broken pieces next to each other, repair one at a time, as each piece of glass supports the other. Alternatively, take the whole panel/window out and do it on the bench.
Always lead to the cartoon line, not the glass. This ensures accurate completion of the panel. If the glass is slightly too small, the cement will take up the gap (assuming the flange of the came covers the glass – if not, you need to cut another piece of glass that fits). If the glass overlaps the cut line, it needs to be reduced.
Cut the ends of the came shorter than the glass. The best way to determine this is to place a piece of came of the dimensions being used for the next edge on the cut line. Use it to determine the length and angle for the cut. The object is to have each piece of came butt squarely against the passing came, to make a strong panel and to make soldering easier.
The first thing to do is to take the piece of glass out and remove the came, 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.
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, 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. Take a felt tipped pen (Sharpie) and run it along the edge of the came, marking the 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.
In this instance the term ‘dressing the cames’ means to close or bend the leaves/flanges of the came toward the glass. It provides a neat rounded appearance to the lines, traps the cement you have already added, presents less area for the rainwater to collect, and makes polishing easier. It is also the time when you may break the glass by putting too much pressure on the glass, so be careful!
Dressing the cames is done with an oyster knife or fid. It is best to avoid metal and better to use wood sticks or plastic tools. The pressure is placed on the came rather than the glass. Run the fid lightly at a shallow angle along each flange of the came. It is helpful to use a finger of your other hand to guide the fid along the cames. You may want to do this several times, as repeated light pressure will cause the flanges of the came to move gently toward the glass with less risk of breaking the glass. This can only be done while the cement is pliable. If it is done after polishing, you will need to re-do the polishing, as it will make the edges of the came silvery rather than shiny black.
If you have consistent difficulty in sliding the glass into the came, you should consider dressing the came before use. Dressing the came 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 away from the straight.
There are at least three kinds of implements in common use to cut lead came.
Lead nippers or lead dykesLead nippers/dykes are a kind of adapted side cutters, used for cutting wire and by electricians. But these have the bevel only on one side of the jaws, making them almost useless for anything other than cutting lead. This arrangement only crushes the lead on the cut-off side and also leaves a minimum of lead next to the back of the jaws.
The jaws of the dykes are aligned in the same angle as the heart of the lead, cutting across the leaves of the lead. They do not cut from the top and bottom of the came. These are very quick for right angle or very oblique angles on the came. However they are of little use for acute angles.
Lead knivesFor more acute angles, blades are more commonly used. These can be either straight edges or curved blades. The straight edge lead knives are essentially putty knives or stiff scrapers sharpened to an acute angle. This kind of knife is normally wiggled from side to side while applying pressure to work through the came.
Other knives are curved to make rocking back and forth easier. There are a variety of knives such as the Pro or Don Carlos. Some look more like a scimitar than a lead knife! These are used to rock along the line where you are cutting the came.
What ever kind of knife you are using, be sure to be directly above the knife, looking along the blade to ensure vertical cuts.
SawsOf course, saws are sometimes used. The blade needs to be coarse toothed to enable the soft lead to drop out of the teeth. These saws can be hand held or table saws. Normally, it is quicker to use lead dykes or knives. However, if you are in production mode, a powered table saw may be worthwhile.
Make a straight cut across the outside came and put that trimmed end into the corner and along the vertical wood strip. The lead should be longer than the leading cartoon to accommodate the length of the upper horizontal. So the length must be longer than the width of the perimeter cames. If it is even longer, the extra can be trimmed off after soldering.
Next butt a trimmed piece of perimeter came along the horizontal wood strip. This one should be shorter than the cartoon. It should be half the width of the perimeter cames to allow the vertical came to butt against it. The reason for having the vertical cames running from bottom to top is that there is a fraction more strength in the heart of the came going all the way to the bottom of the panel, rather than resting on the flanges of the came.
These perimeter cames should be held in place with horseshoe nails. Try placing the nails only where a lead line will be soldered in order to cover any nicks the nails might make. Alternatively, you can place the nails at the ends of the perimeter cames to keep them from sliding vertically or horizontally.
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.
Glass can do most anything. From bottles to spacecraft windows, glass products include three types of materials:
- Formers are the basic ingredients. Any chemical compound that can be melted and cooled into a glass is a former. (With enough heat, 100% of the earth's crust could be made into glass.)
- Fluxes help formers to melt at lower temperatures.
- Stabilizers combine with formers and fluxes to keep the finished glass from dissolving, crumbling, or falling apart.
Chemical composition determines what a glass can do. There are many thousands of glass compositions and new ones are being developed every day.
Formers: Most commercial glass is made with sand that contains the most common former, Silica. Other formers include:
- Anhydrous Boric Acid
- Anhydrous Phosphoric Acid
But melting sand by itself is too expensive because of the high temperatures required (about 1850°C, or 3360°F). So fluxes are required. Fluxes let the former melt more readily and at lower temperatures (1300°C, or 2370°F). These include:
- Soda Ash
- Lithium Carbonate
But fluxes also make the glass chemically unstable, liable to dissolve in water or form unwanted crystals. So stabilizers need to be added. Stabilisers are added to make the glass uniform and keep its special structure intact. These include:
- Barium Carbonate
- Strontium Carbonate
- Zinc Oxide
Based on an article from the Corning Museum of Glass
An important characteristic of the glass is that a very small amount of the tin is embedded into the glass on the side it touched. The tin side is easier to make into a mirror and is softer and easier to scratch.
Float glass is produced in standard metric thicknesses of 2, 3, 4, 5, 6, 8, 10, 12, 15, 19 and 22 mm. Molten glass floating on tin in a nitrogen/hydrogen atmosphere will spread out to a thickness of about 6 mm and stop due to surface tension. Thinner glass is made by stretching the glass while it floats on the tin and cools. Similarly, thicker glass is pushed back and not permitted to expand as it cools on the tin.
The elaborate patterns found on figure rolled glass are produced by in a similar fashion to the rolled plate glass process except that the plate is cast between two moving rollers. The pattern is impressed upon the sheet by a printing roller which is brought down upon the glass as it leaves the main rolls while still soft. This glass shows a pattern in high relief. The glass is then annealed in a lehr.
According to the website of the London Crown Glass Company, broad sheet glass was first made in the UK in Sussex in 1226 C.E. This glass was of poor quality and fairly opaque. Manufacture slowly decreased and ceased by the early 16th Century. French glass makers and others were making broad sheet glass earlier than this.
This glass has thickness variations due to small temperature variations as it hardens. These variations cause slight distortions. You may still see this glass in older houses.
In more recent times, float glass replaced this process.
There were a number of advantages to this technique. It allowed a variety in the depth of red – and other deep colours - ranging from very dark and almost opaque, and sometimes merely tinted. The other advantage was that the colour of double-layered glass could be engraved, abraded, or etched to show colourless glass underneath. Other base colours are also used in making flashed glass, for example red flashed onto a pale green base.
There still exist a number of glass factories, notably in Germany, USA, England, France, Poland and Russia which continue to produce high quality glass by traditional methods primarily for the restoration of ancient windows.
Cylinder blown sheet glass has been manufactured in France and Germany since the 18th Century. It began to be manufactured in the UK in the mid 19th Century, although only one small company continues manufacturing.
Machine drawn cylinder sheet was the first mechanical method for "drawing" window glass. Cylinders of glass 40 feet (12 m) high are drawn vertically from a circular tank. The glass is then annealed and cut into 7 to 10 foot (2 to 3 m) cylinders. These are cut lengthways, reheated, and flattened. This process was invented in the USA in 1903. This type of glass was manufactured in the early 20th century (it was manufactured in the UK by Pilkington from 1910 to 1933).
The earliest method of glass window manufacture was the crown glass method. Hot blown glass was cut open opposite the pipe, then rapidly spun on a table before it could cool. Centrifugal force forced the hot globe of glass into a round, flat sheet. The sheet would then be broken off the pipe and cut into small sheets. . This glass could be made coloured and used for stained glass windows, but is typically associated with small paned windows of 16th and 17th century houses. The concentric, curving ripples are characteristic of this process.
At the center of a piece of crown glass, a thick remnant of the original blown bottle neck would remain. They are known as bull's eyes and are feature of late 19th century domestic lead lighting and are sometimes used with cathedral glass or quarry glass in church windows of that date. Optical distortions produced by the bullseye could be reduced by grinding the glass. The development of diamond pane windows was in part due to the fact that three regular diaper shaped panes could be conveniently cut from a piece of crown glass, with minimum waste and with minimum distortion.
This method for manufacturing flat glass panels was very expensive and could not be used to make large panes. It was replaced in the 19th century by the cylinder, sheet and rolled plate processes, but it is still used in traditional construction and restoration.
There are a number of ways of categorising glass and this overview of glass types looks at the way the glass is manufactured.
Crown glass is the oldest method of producing sheet glass.
Cylinder glass is also a hand made process that includes broad sheet glass.
Flashed glass was a development to make dense colours more transparent and as a by-product allowed much greater detail by abrading and etching.
Industrialisation of glass production began with the development of drawn glass and table glass.
The glass that we now rely on for large clear windows began with the development of floating glass on molten metal, hence the name float glass. Toughened/Tempered glass and laminated glass are two among many methods of providing greater strength to glass.
This blog is set up to disseminate these little ways to all who want to develop their skills and find other ways of working. My way is not always the right way. It is certainly not the only way to do things. But some suggestions may make the work easier.
This will also include a variety of pieces of information about the characteristics of glass, equipment, and of course my opinions on a variety of glass related matters.
So I hope this will become a useful little pile of data for others to mine. Like miners, some people will keep some things and throw others away. That's fine with me. Disputes on my methods and opinions are also invited.