APPLICATION OF COPPER FOIL and SOLDER
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 adhere properly.
- 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 scissors.
- 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 project.
- 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 “tinning.”
- 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 surface.
- 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.
Wash your 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 of flowing.||Iron is too cold.|
|Can’t seem to get beading smooth.||Wrong kind of solder for job. Did you flux? Iron too cold or too hot. Too much or not enough solder.|
|Solder won’t stick to copper foil or lead.||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.|