Finishing Copper foil Projects

What order do you clean/wax/patina?

A question with many answers.

Almost everyone agrees that cleaning all flux and oil residues are the first stage of finishing. Once the panel is rinsed and dry the stage is set for the finish. The solder is then cleaned of any oxidisation by using steel wool, brass wire brush or some other mild abrasive.

However the industry does not use any metal in the cleaning of any surface to be patinated. Never use abrasive or corrosive materials to clean solder lines holding glass.  The most aggressive cleaner used is that intended for fibreglass baths. Do not use metal or scouring pads when cleaning.

Again opinion differs on the order of processes:

Some wax the solder lines and polish before applying patina.

Some apply patina and wax afterwards.

Both claim success with their method.

Comments from industry indicate that the order is:

Clean

Patina

Protect

Fluxed Foil

 If you take a breaks from soldering do you need to clean it right away or is flux okay to sit? 

Fluxes are mild acids. If left a long time, they will corrode the copper foil – not enough to damage it, but enough that the solder will not take to the foil as it should.   A long time is measured in days rather than hours.

If the flux has been left overnight, it probably will be OK.  The test is whether the solder flows as it did before the interruption.  If it does not, then the flux needs to be cleaned off the foil, and the foil polished with steel wool before re-fluxing.

Liquid flux needs to be used before it dries to be active.  Any interruption which will be long enough to allow the flux to become dry will mean a clean up of the surface is necessary before leaving the piece for a day or more.

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.