First Time Copper Foiling Stained Glass
Solder will not adhere to glass, copper foil is wrapped around the edges, leaving only enough exposed surface for the solder to stick. A neat, even foil wrap will give a base for a neat, even soldered joint. The solder is the framework of the shade that holds it together, not the copper foil.
Copper foil is available in rolls in several widths, coated with a special pressure sensitive glue which adheres to the glass, holding it in place until the soldering operation is completed. This eliminates the old method of cutting strips from sheets of foil and wrapping without the adhesive backing to hold the foil in place.
Stained glass varies in thickness, but it is generally about 1/8 inch thick.
For glass 1/8" thick or less use 3/16" wide foil
For glass up to 5/32” thick, 7/32” width tape can be used. For heavily textured or rippled glass it is recommend that 1/4” or wider tape be used; this allows sufficient width to cover the edge of thicker glass and to cover a break that has some slant.
The foil strip is easily trimmed with scissors if the paper backing is left on.
The untrimmed edge is placed on the outside for a nice even seam. As a rule the width of the foil for very small pieces is trimmed much closer than for larger pieces. Make wider foil wrap near the top aperture opening so strong solder seams can be made.
As you remove the pieces for foiling do not pull the pins all the way out; pull them just far enough out so each glass piece can be tipped up, removed, foiled and repinned.
Pull pins part way out to remove parts. Foil wrap and repin.
In wrapping, remove the paper backing, position the strip and anchor the end firmly at a corner with your forefinger. To prevent uneven overlaps, cut the foil at a sharp corner without an overlap.
Hold the parts edgewise; learn to look at the corners of the piece and position the foil evenly at each corner. The space in between will automatically be even.
To fold over grip the edge with the thumb and forefinger, push toward the center, work all the way around. Lay the piece flat against a small piece of plate glass or other hard flat surface and press down firmly on each side to flatten the stubborn corners.
Smooth and rub (burnish) with a pointed section of hardwood dowel or any smooth pointed tool. Burnishing flattens any air pockets or stubborn corners. If you are working with rough-on-one side glass, the pointed hardwood dowel is of great help.
Smooth foil with a pointed section of hardwood dowel.
Foiling Rippled or Drapery Glass
Examine the edge of the rippled glass. Use copper foil that is at last 1/16” wider than the widest point. As you wrap, look at the flat back side and leave about 1/32” overlap. Do not crimp the rippled side until you have contour trimmed the foil with small pointed scissors. Trim leaving about 1/32” above the edge on the rippled side.Foiling Jewels
In many of the antique lamps, smooth round glass jewels were used to represent clusters of grapes and accent points. Ruby red was the color used most often in the old lamps.
When installing jewels, rough the edge with a grindstone so the copper foil will adhere better. Only a very narrow strip of foil is needed. Copper foil is easily trimmed with scissors.
The jewels will show up better if they are positioned slightly above the surface of the form. Place pins under them so the rounded part of the jewel is held above the flat stained glass.
Hand pressed jewels, turtleback tiles and scarabs have a lip around the base of the jewel that makes foiling easier - just foil the prepared lip.
Care of Foiled Parts
Copper foil will oxidize and turn reddish with age. This is not a problem, flux will clean the foil for soldering, but if you apply flux and do any soldering, you must clean the excess flux off with a damp cloth or the foil will turn green from oxidation and need to be replaced after a few days.Black and Silver Backed Copper Foil
Use these foils with lightly colored cathedral and clear glass to hide the copper foil color and to create special effects.