Hinges in Sun catchers

How critical is it to reinforce hinge joints?

It is often suggested that straight, or nearly straight, joint lines need to be reinforced. “Restrip” or similar reinforcements within the hinge are often suggested to strengthen the panel.

However, such reinforcement within the bands will do nothing to resolve the hinge problem. To make a panel resistant to folding at the hinge, the reinforcement needs to be at right angles to the hinge. This will resist the bending of the panel most effectively.

If the hinge joint does not extend to the outside of the panel, external reinforcement will be needed from side-to-side to strengthen the panel against bending.

In a hanging item bending at a hinge is not the same kind of problem. What is a concern is that the pieces will separate. Edge reinforcement such as wire soldered to the edge all around the panel. This is because the adhesive is degraded by the heat of soldering and cannot be relied upon to hold the weight below the hinge joints.

Zinc came borders are often recommended as the solution to creating stiffer panels. It certainly has strength advantages, but is generally limited to straight lines or regular curves. For more free form pieces, soldering a thin copper wire to the edges and covering with hobby came provides a strong edge to a hanging panel. The wire also can provide strong hanging points independent of solder lines emanating from the interior.

Vase Cap Attachment

Tinning the brass

Brass transmits heat much more quickly than lead, so a considerable length or the whole of the piece, e.g., a vase cap needs to be heated to avoid the cap acting as a heat sink and so not allowing even tinning of the object.

When tinning any brass pieces, like a lamp cap, rub it with fine grade steel wool until bright, then wash the residue off and dry. Apply flux with a fresh flux brush, and hold the piece with a pair of pliers as a precaution against getting burnt.

At this point you can heat the brass or vase cap with a blow torch at a low heat to warm the whole piece. Begin applying the solder while playing the torch over the vase cap to allow the solder to flash along the brass smoothly.

Alternatively you can work without the blow torch. Apply a bit of solder to the tip of the iron. Touch the piece with your hot soldering iron, let the piece heat up a little, and then start moving the iron slowly and smoothly over where you have applied the flux. This does not provide as smooth a tinning as the blow torch method.

When the whole piece has been covered, wash it, dry, and then inspect for any missed spots or unsightly solder blobs. Apply a little bit more flux and touch with your soldering iron. If you are doing a lot of this kind of work, an 800 degree iron tip will speed up your work.

This method will give a strong solder to solder joint that requires much less time when soldering the cap to the rest of the lamp shade.

Attaching the vase cap

Tinning the vase cap is important to a secure attachment. The whole of the lampshade hangs from the attachment of the vase cap to the solder seams of the shade.

Once the glass of the shade is at least tack soldered, place the vase cap on top centrally covering the void at the top of the shade. Flux and apply solder so the solder seams to make sure the cap is securely fixed to the rest of the shade.

It is a good practice to turn the lampshade over and apply solder from the seam to the inside of the vase cap. For larger, heavier shades, it is important to run copper wires from the underside of the vase cap, near its centre into the solder lines for 5cm/2”. This often means that the wire will need to be bent in several directions to follow the seams, so a thin guage wire is most useful. This also implies multiple wires need to be run from the cap into the seams. I find multiples of three are important to maintain long term stability. So, 3, 6, or 9 wires may be needed. My usual is at least 6.

Choosing copper foil backing

Why are there different colour backings on copper foil?

This is a common question.   The answer has to do with the finished piece, and only matters if you are using transparent glass. If you are using opaque glass that you cannot see through it doesn’t matter so much which type you use.

The backing should be of the same colour as finish to the solder lines. Since you can see through transparent glass, you will be able to see bits of the back of the copper foil, especially at certain angles. It would look peculiar to have a piece with a beautiful black patina, only to catch glimpses of copper when you are looking at it.

Therefore, if you are planning to patina your piece black, use black-backed copper foil. If you are planning on leaving it silver, use silver-backed copper foil. If you are planning to patina it copper, use copper backed copper foil.

You can, of course, be safe and use black backed foil all the time.  Even if the final colour of the solder is other than black, the black will not attract the viewer's eye so much as a contrasting colour.

Choosing Copper Foil

 What foil should I choose?

Choice of foil relates to:

Glass thickness

Thin glass requires thinner foil to maintain a neat solder line of about 3mm. Thicker glass requires thicker foil to maintain the same width of solder line. So 2mm glass might require 4mm foil, and 3mm glass need 5mm foil.

Glass texture

Heavily textured glass usually needs thicker foil, as the thickest part of the glass is greater than the thickness of average glass. This requires a little experimentation to get the one you like best, but usually is one step up in width from your usual. Remember you are looking at only one half of the resulting solder line thickness on each piece of glass.

Desired width of solder line

The desired width of the solder line will also affect the choice of foil. If you like a thin line of solder, you should choose foil that is only 1 or 2mm wider than the thickness of the glass. This will give a solder line of 1 or 2mm wide. Be careful when choosing a thinner width. You still need enough foil on your glass to maintain the strength of the solder bead. If you like wider lines, a foil that is 3 or 4mm wider than the glass thickness will give a 3 to 4mm wide solder line.

Ease of Use

Foil comes in different thicknesses as well as widths. Thinner is easier to form around inside curves, but tears more easily. Thicker is more robust, but crinkles up more on curves and so needs more burnishing. Mostly it is personal choice on what is easiest to work with.

Trimming
Of course is possible to trim the copper foil to be thinner after foiling.  This can be to even up the line, or to thin it.  Gentle pressure with a sharp craft knife will cut the foil to the width you want. You may want to do this when all the pieces are assembled before soldering.  This gives you the opportunity to see the width of the resulting solder line will be.  It is also the time when you can see what the line of the solder bead will be and make adjustments before beginning the the soldering.

Care in the Operation of Soldering Irons

The most important element in the deterioration of soldering iron bits is long idle times. This is where you leave the iron on, and not in use, for a long time.

Have everything ready when you start soldering, so the iron will be used continuously, and will not sit there building up heat, while you get ready to use it again. An idle iron will keep heating to its maximum capacity, and without anything to transfer the heat to, it will start burning off the tinning, after a short while. So if you will not be using the iron for a while turn it off until you are ready again.

Even if you have a temperature controlled iron, idling for a long time at the set temperature does have the same but lesser effect as one without temperature control.  

The other elements leading to deterioration in performance come from lack of cleaning and tinning of the tip. When the coating of solder burns off or is coated with carbon you get poor heat transfer from tip to working surface making it appear that the iron is not heating properly.

An example of a heavy stand

It is important to ensure your electrical supply cord is kept away from the hot end of the iron to avoid burning through the cord.  In another studio the supply was from overhead so the cord was never trailing across the work or the bench.  A solid stand to place the iron into is important to both avoiding damaging the electrical supply and melting other things around.  To assist this, all materials not relevant to the soldering process should be put away before the soldering begins.

Protect yourself from burns from the iron or hot solder.  Always keep your hands away from the hot end of the iron.  Always place the iron into the holder when making adjustments of any kind that interrupts the soldering.  Keep burn relief, such as aloe vera by the soldering station.

Eye protection is important, because the flux fumes often contain chlorine compounds that can affect your eyes.  This is more important than breathing protection.  If good ventilation is being used, that will be enough for lung protection, and will reduce the risk to eyes, even then, eye protection should still be used.

Templates of Openings

 If you have an irregular opening to fill, it is best to take a tracing of the opening. Usually this will be in larger openings and a helper may be necessary to assist.

Materials

The material used to take the template must have a few characteristics:

• It must be stiff enough to have the minimum possible bend over the width or height of the opening

• It must be easy to mark with a pencil or other implement

• It must be easy to cut or shape

• It should be light to make it easy to lift it to the opening for the many adjustments that will be required.

A number of materials can be used: stiff card, mounting board, corrugated cardboard, thin plywood, and many other sheet materials. I have found double walled stiff corrugated cardboard easy to use.

Irregular rectangles

If you have found or can see that the opening is not a true rectangle and cannot determine where any right angles are, you need to take a template.

The objective is to make a piece that will fit into the opening without bending or being too small for the space. It will be the same size as the finished panel and so you will be able to put the finished panel into the opening without needing to trim or expand the panel.

First, trim the sheet of material you have chosen to use to a size a little larger than the measured size. Place the uncut side along one of the long sides of the opening. If the opening is a portrait format, place it on the right or left side as convenient to you.

Next, adjust the bottom by marking a line on the sheet. This is where a second person is very useful. One person can hold the sheet in place on outside of the opening and the other do the marking from the inside –in the case of the rebate being on the outside and vice versa if the rebate is on the inside. The marked line should be as close to the edge of the rebate as possible. The special case of an opening in stone will be dealt with separately.

Then take the sheet to a place where it can be safely cut. A long metal straight edge and craft or “Stanley” knife are often the best aids to cutting straight lines. Replace the sheet into the opening after cutting, and make any adjustments to the size and angles of the sheet at the bottom by marking and cutting as necessary.

When the side and bottom are adjusted, start on the other side. Proceed as for the bottom. When the side is finished, start on the top. Finally, present the whole sheet to the opening to make sure it slips into place with no snags, or bending of the sheet.

It may be that the opening is too large for a single sheet. In that case you will need to work with two or more sheets and try them together for the final fitting into the opening. You can put them together in the window. You can fasten them together with tape or other fasteners to make one sheet. You can also make two parallel lines both at angles and at intervals across the sheet so that when you get back to the studio you can exactly reproduce the full sheet by matching the marks and then firmly fastening them together. This makes transport of large templates much easier.

You will know that a panel made to a template made in this way will fit into the opening, no matter how irregular the opening may be.

Circles

Occasionally the window is circular and sometimes an oval. In both cases a template is important. The circles and ovals are rarely is exact or symmetrical. Take the template in the normal way and then ensure you mark the verticals and horizontals for the opening. You often can use the jointing in the woodwork to help with these. Also mark any other reference points from the opening. Finally, mark which is the outside and which the inside.

Round heads

Round headed openings can be considered as a special case of a circle. The horizontal you must find is the shoulder of the window. This is the place from which the curve springs on each side. The opening is generally vertical up to this point and then begins the curve.

You need to make sure you have marked where this shoulder is on the template. You should indicate any reference points from the frame onto the template.

The join to the lower part of the window must be made obvious. Normally there will be an overlap between the lower rectangular template and this approximate half circle. You need to mark where this overlap occurs, if you do not fasten the two sheets together. This can be done by marking across the two sheets in a few places. This will enable you to join them exactly back at the studio.

Irregular openings

Irregular openings such as trefoils and other tracery need to have templates taken with consideration on how the final panel can be put into the opening. In the cases where the whole of the rebate is exposed, it is normally possible to put the panel in as a single whole piece.

So, the template is taken as for any other opening. It is more complex and time consuming as there are so many more sides than in a simple rectangular or circular opening.

Stone

When the opening is in stone, slight variations occur in the process of taking a template. The main difference is that the rebates are concealed. The rebates are slots into the stone. Thus, the template must slip into the slotted rebate. In these cases, the stiffer the material being used to take template, the better. Usually, thin plywood is the best material, as it has to be manipulated many times and in ways similar to the final panel.

Things are further complicated, as tracery is more common in stone than in timber framed openings. A complex opening shape may require two or more parts to enable the panel to be inserted. The taking of a template will help greatly in figuring out how the panel will be inserted into the opening.

Additionally, when the template is in position, you should mark the visible portion of the opening onto the template. Mark which is the inside and which the outside. Finally, mark on each template which side has the deeper slot as this will help in installation.

Using these methods of taking templates will make restoration or drawing up a new design much easier and more accurate, leading to an easier installation.

Air Brushing on Glass

Air brushing paint and enamels onto glass can give extremely subtle graduations of colour and tone.

Air brushing onto glass is a little different than onto other slightly absorbent surfaces. As glass cannot absorb the moisture from the material being sprayed, the medium needs to be allowed evaporate.  This means that each layer of paint must be allowed to dry before the next layer is applied.  If too much liquid is applied to the glass, it will bead up giving a stippled appearance to the finished result.

The two main media that you can use are water and alcohol.  The advantage of spirits is that it evaporates from the surface more quickly than water.  Also apply in a warm rather than cold place. You can use a hair dryer on low speed and power to assist the drying.  This will reduce the waiting time between applications.  You do not need to use any gum arabic in the mix to help it flow, but a drop of liquid soap will help to break the surface tension of the medium.  This avoids any "beading up" on the super clean glass.  

The consistency of the mix of the paint or enamel with the medium will need to be many times thinner than that used for painting with a brush. Also the air brush will need to be able to cope with the relatively large (in relation to inks and other paint) particles that make up the glass paint. This may require a little experimentation to find nozzle sizes that can cope with the glass paint particles.

Before you begin air brushing you must prepare the glass so it is very clean.  Clean the glass very well with clean water followed by isopropyl alcohol.  After this thorough cleaning and drying, use some of the paint to rub the glass. As the paint is a slight abrasive, it cleans off anything the other cleaning methods could not get off.

The paint should be applied in steady sweeps across the area to be covered at least 10cm/4" from the surface.  Start moving your brush before you switch on the paint and keep moving after you stop applying the paint.  This avoids heavy applications at the start and finish. As there is no absorption of the moisture by the glass (as there would be on paper or board), you must pause after a very few passes.  This is where the spirits show their value, as they evaporate more quickly than water, allowing you to apply the next layer sooner.

One thing you will notice is that the paint will settle within the medium unless you agitate it frequently. So you should make sure the paint is evenly dispersed within the container by agitating it before starting each layer. The movement of the air brush during application will be enough to keep the paint suspended in the medium while you are applying the glass paint or enamels.

Raphael Schnepf Workshop

Because air brushing puts very small particles into the air you need to observe various precautions. You need to have a dust mask on at all times you are air brushing. You should do this in a spray booth with extraction if possible. If not, you need a well-ventilated area and very good clean up afterwards.