Soldering Interruptions

Do you have to finish soldering/cleaning all in one go? 

Interruptions in soldering are possible, but they should not be long. The flux is an acid and will affect the copper foil. The acid although mild, will began to cause enough corrosion to make further soldering difficult after a few days or a week. If the recommenced soldering is not working as previously, the flux needs to be cleaned off and the oxidisation layer removed from the foil. The easiest way is to use fine steel wool and carefully polish the foil with it. Then flux the area you think you can accomplish in the time you have.

If there is likely to be a significant time before soldering can begin again, clean off the flux and finish with a neutralising compound, or a solution of baking soda. Dry and cover with a plastic sheet, or if small enough, put it into a sealable plastic bag.

If it is a big job in relation to the time available, only flux what can be achieved in that time. This saves clean up time. Although it may be necessary to polish a thin layer of corrosion from the foil before resuming the soldering.

Cleaning Solder Beads

After soldering, cleaning and drying your piece is essential to good patina results.  Ensure the panel is completely dry, not just the solder lines.  Many people recommend metal wools or brushes, but the information from industry is to use mild non-metallic materials to prepare the solder lines for patination.

Green scrubbies, or more environmentally friendly plastic free scrubbers are a good choice.  A short bristled plastic free brush that is not really stiff will work well too.  

The cleaning solution should not be anything more abrasive than that used on fibreglass bath fittings.  If this needs to be used to be sure of clean solder, the panel must be rinsed again with water that has as few chemicals and minerals as possible.

Omitting this step increases the chances of developing whitish blotches later on the solder lines. However, including this step makes a better base for applying the patina, if you are using any. 

Revised January 2026

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.