THE COPPER FOIL
The copper foil technique, method made
popular by L.C. Tiffany at the turn of the century, involves
wrapping the pieces of glass with copper foil and soldering them
together along the length of the seams.
Copper foil can be used as an alternative
to lead in any instance at the personal preference of the user. It
is much stronger than lead when soldered, needs no putty, is
waterproof, and allows you to do intricately detailed projects
where the bulky look and weight of lead would detract from the
aesthetics of a delicate design.
The copper needed for this technique is of
a thin, foil-like gauge. It has an adhesive on one side and is
backed by protective paper. Copper foil is sold in 36-yard rolls
and is available in several widths and gauges. Some of the common
sizes used are 5/32", 3/16", 7/32", 1/4",
5/16", and 3/8". The actual gauge of the copper can be
1 mil, 1-1/4, or 1-1/2 mil. the thickness of the glass you are
using and the finished look you want to achieve will dictate your
For instance, if you use very wide foil
such as 3/8" to wrap thin glass, you will have very wide
seams in your finished project. Wide foils such as 5/16" and
3/8" are usually used where strength is an important factor
or when very thick glass is being used. Beginners using standard
1/8" thick machine-made stained glass should start with
1/4" or 7/32" foil. These sizes are easy for the novice
to handle. With a little more experience at cutting, you may like
the narrow seams that 3/16" foil produces. The choice of
width and milage is one of personal preference. As you do more
stained glass, you will find that you have definite preferences.
The allowance between your pieces of glass
using the copper foil method is 1/32". This means that the
lines of your pattern should be 1/32" thick. This allowance
is the space that your copper foil takes up. When cutting using
the traditional method, you must cut every piece of glass to the
inside of these lines. If you use the paper pattern method this
allowance is cut out of the pattern. If you are using a full-size
pattern that is drawn with 1/16" lines, and using the
traditional method, cut slightly to the inside of these lines.
TOOLS FOR THE COPPER
Listed here are the tools and supplies you
will need for the copper foil method. Some tools are optional,
while others are absolute necessities. Optional items are marked
with an asterisk (*).
||*lathkin or fid
||*foil pattern shears
||ruler or straight edge
|*circle or lens cutter
||*light box or table
||oaktag or file folder
||flux and brush
||glass marking pen
||*diamond bit grinder
APPLICATION OF COPPER
After all of the pieces of glass in your
project are cut and refined to fit properly, you are ready to
begin foiling. Every piece of glass must be wrapped in copper
foil. Before you begin it is important that your glass is clean
and free of dirt and oil from your cutter or the foil will not
- Step 1. Remove the protective
paper backing of the foil as you work. First, center the
glass on the foil. Make sure that there is an even amount
of overhang on each side of the glass. Wrap the foil
around each piece of glass, overlapping it at least
1/4" from where you began. Cut off the excess with
- Step 2. Crimp the foil around
the edges of the glass. With a blunt piece of wood or a
fid, burnish the foil on both sides of the glass and
along the outside edge so that the foil adheres to the
glass firmly and smoothly. A sloppy wrap job will ruin
the appearance and affect the strength of the finished
- Step 3. After wrapping and
burnishing all of the pieces of glass, position them on
your pattern. As with the lead came method, use lath
strips to keep your panel squared up. Freeform projects
can be held in place with horseshoe nails or push pins.
- Step 4. Apply flux to the
foiled seam joints.
- Step 5. Tack solder to all of the
joints in your project. Melt just enough solder onto each
joint to hold the pieces firmly together so that they
will not slip or slide apart. Neat, skillful soldering is
not necessary at this point because during the next step
the tacking will be remelted.
- Step 6. Apply flux along the
foiled seams of the project that you will be soldering
during this work session. If you apply flux to the copper
and leave it unsoldered for too long, it will result in
badly tarnished, oxidized foil that will be difficult, or
impossible to solder without a thorough cleaning. Should
this happens, you can remove the oxidation with a soupy
mixture of water, vinegar, and table salt.
- Step 7. The final soldering
step is called "beading." This process involves
building up the solder to a uniformly rounded bead along
all the seams. Move the iron (with the tip held
horizontal to the seam) and the solder continuously along
the length of the seam. Remember that you can't bead a
seam if you don't use enough solder. Likewise, too much
solder will be difficult to uniformly bead. You will
learn the proper amount to use through practice and
experience. Bead both sides of your project.
- Step 8. If you are not going to
frame your panel in a wooden frame or U lead came, you
will want to take the outside edges have a more finished
appearance. You now want to bead the perimeter. First
apply a very light coat of solder to the perimeter on
both sides of the piece. This is called
- Step 9. Now bead the edges.
This is accomplished by holding the edges to be soldered
perfectly horizontal to the table. Melt just enough
solder on the edge so that it "rolls" down over
the sides of the foil, uniformly rounding the edge. This
adds strength and a more professional look to your work.
Please note that on curved edges you can only bead about
1/2" at a time; then carefully allow the solder to
set, and slowly turn the piece so that every 1/2"
section you are working on is horizontal to your work
- Step 10. If you are not going
to frame your project, solder on loops for hanging at
this time. Pre-formed circles of brass or copper can be
purchased from your supplier or you can make you own
simply by curling 18 or 20 gauge brass or copper wire
around a dowel.
project in warm water and mild detergents to remove the
flux or use a commercially prepared flux remover. You are
now ready to apply patina to the solder. Patina changes
the silver color of the solder to an antique black or
copper. Commercially approved chemical mixtures are
available. Wear rubber gloves to protect your hands from
the chemicals, and follow the directions on the label.
When finished, wash and dry your panel.
SOLDERING PROBLEMS AND TIPS
|Solder falls through seams to
other side when soldering copper foiled pieces.
||Soldering iron is too hot or you
are holding the iron in one area too long. Put a damp rag
or sponge under the area you are soldering.
|Beading of seams is too flat.
||Not enough solder.
|Beading is lumpy -- peaks instead
||Iron is too cold.
|Can't seam to get beading smooth.
||Wrong kind of solder for job. Did
you flux? Iron too cold or too hot. Too much or not
|Solder won't stick to copper foil
||Did you flux? Copper foil may be
oxidized; clean with vinegar, salt, and water solution.
Lead may be oxidized; wipe clean, dry, and rub with fine
steel wool or wire brush.
|Solder splatters into little balls
all over the glass.
||Iron too hot; purchase rheostat
for your iron. This will control the current to your iron
and control the heat output.
|Lead came melts and disappears
before your eyes.
||Directly touching the lead came
with a very hot iron. Position solder at joint, iron on
top. Let solder flow down on lead came.
to "Making a Lampshade"