All photos and designs protected
Once the glass pieces have been cut and the edges carefully ground (especially essential for copper-foil), strips of copper foil tape are pressed onto the edges. Various widths of copper tape are available for different thickness of glass or to create special effects. The copper foil is usually just wide enough to wrap around the edge of the glass piece and leave a line of copper on the top and bottom of the glass edge.
After the edge is wrapped with copper it is important to burnish the copper to achieve a smooth surface. All of the copper wrapped pieces are set in place, cleaned with flux and soldered together. In soldering it is important to use a rheostat to control the temperature of the iron. Solder is melted with the tinned tip of the soldering iron and flowed onto the copper tape to create a rounded smooth joint.
With copper-foil pieces a liquid patina can be used to change the color of the silver solder lines to a copper color or black. The patina is brushed over the cleaned solder lines and a chemical reaction changes the color of the solder.
As with the lead came construction, copper-foiled pieces are also finished with a rigid zinc came soldered to the perimeter of the piece.
Finally, after a good cleaning and application of paste wax, the window is ready to be polished and displayed.
The copper-foil technique is used for this stained glass piece entitled "Horny Toad Hangout"
When creating a drawing or pattern for stained glass one must remember certain rules of cutting and breaking glass. Glass wants to follow its molecular structure and break in a straight line. Thus, straight lines are much easier to cut than curves. Tight inside curves are most difficult requiring several smaller curved scores (the line made by a glass cutter) to create the tight curve. Unless you have access to a mechanical glass saw acute inside angles or curves should be approached with caution. Very acute angle cuts may result in pressure cracks in the glass after it is assembled.
Once the design is drawn it must be modified to indicate the lead or solder lines to create the pattern or cartoon. I have found that freezer paper with one side coated in wax makes an appropriate material for making the pattern or cartoon.The wax coating helps the paper hold up during grinding. Adhesive vinyl paper (contact paper) is great for using a pattern multiple times as in creating window sparklers or glass figurines.
Using graphite or copy paper make 2 copies of the cartoon. One copy (the ground copy) will be used to assemble the glass pieces which are cut using the other copy of the cartoon.
Cut glass pieces from the cartoon are laid onto the ground pattern and joined by aligning the edges of the glass pieces in channels of H - shaped lead came. It is a good rule to use gloves when handling lead. A lead came knife or pliers are used to cut the lead to length. The lead came must be bent into shape around curves so the glass pieces fit tightly together. Fids are helpful plastic tools with jobs like opening the lead or zinc came channel to accept the glass.
Once the pieces are all fit together the joints of the lead came are fluxed and soldered to hold the glass. Acid flux is used to clean the joints and remove oxidation before soldering. A rheostat will help control the temperature of the soldering iron to prevent melting the lead too.
C -shaped zinc came is used to frame the entire piece and hold the edge pieces together. The rigid zinc came is fitted around the perimeter of the piece and soldered in place. The zinc came pieces are cut using a hack saw or a mechanical cutting tool. I prefer 45 degree mitered corners but but-end joint are also common.
Lead came pieces are finished by glazing and whiting. Glazing compound is pushed into all channels and joints of the stained glass to create a watertight seal. The glazing is sealed by rubbing whiting compound on top of the glazed joints.
There are two major techniques used to create a stained glass window - Tiffany's copper-foil technique and the historic lead came technique.
- In the copper-foil technique individual pieces of glass have their edges wrapped with thin copper foil tape which is then soldered to join the glass pieces. Louis Comfort Tiffany's Studio popularized this technique in the 19th century. This technique allows for tight curves and smaller pieces to be joined together.
- In the lead came technique, the edges of the cut glass pieces fit into the channels of a length of extruded lead came in the shape of an H or I beam. Only the joints of the lead came are soldered to create the window. This is the historic process for creating stained glass established hundreds of years ago.
If you are familiar with computer graphic formats, I would equate the lead came technique to a GIF image where simple color fields are displayed. Whereas the copper-foil technique would resemble a JPEG where intricate designs with tight curves can be created.
1. On the cartoon, number the first pieces to be cut and use the pattern scissors to cut each piece from the cartoon. Pattern scissors are best used for lead came projects. For copper-foil patterns just use regular scissors to cut out the thin line of ink on the cartoon.
2. Use double-sided tape to adhere the pattern piece to the glass to be cut. If using vinyl or contact paper just peel off the back to adhere to the glass.
3. With the glass cutter score a line from one edge to the other by pressing the cutter onto the surface of the glass and draw it across. The line must go from one edge to the other or the glass may break irregularly. As the cutter scores the glass you should hear a crackle - the glass should "sing". If you don't hear the "sing" or see a line you have not pressed hard enough or the cutter needs oil.
4. Several techniques for "breaking the score" or separating the cut pieces include:
Tapping on the back side of the score with the ball end of the cutter to create a crack along the score. Then separate the glass pieces by pulling down and away from the score. Breaking pliers are often used in this step to pull the pieces apart.
A straight line score across a piece of glass can be separated by laying the score along the edge of a table and pulling down and away from the score in a sharp movement.
Breaking pliers, with their flat pincers can be used to pull the glass apart by pulling down and out from the score.
5. Shape rough edges by removing small fragments with the grozing pliers.
6. Finish shaping the glass piece by grinding the edges with a water feed grinder.
7. Place the glass pieces onto the ground pattern in their proper place. Pieces of wood moulding should be used to secure the perimeter of the piece on the ground pattern. Ribbed or square nails can be used to hold individual pieces in place while filling out the pattern. I actually prefer two use pieces of scrap 1/4 glass pieces to hold pieces in place. See picture of the "Horny Toad Hangout" piece in progress to the right .>>>