Removing the Broken Glass

• 1). Use scissors or shears to cut the aluminum sheet to approximately 1 inch by 6 inches.
  
  
• 2). Each section of stained glass that has been assembled with the copper foil method has foil around it. The pieces are then soldered together and all of the copper foil is covered with solder to reinforce the soldered joint and give it a consistent look. Heat the soldering iron and run the solder around the piece that is to be replaced 1 inch at a time. Running the solder means to heat it until it is liquid again.
  
  
• 3). Slip the aluminum sheet in the open area you've just created in the joint. Solder does not adhere to aluminum and this will prevent the joint from closing again.
  
  
• 4). Run the solder from the next inch or so and slide the aluminum toward the newly opened area. The first section you opened is no longer in danger of closing because the head does not travel far from the soldering iron. Continue to heat and run solder in 1-inch increments moving the aluminum to the section previously opened until you have worked your way around the entire piece of glass. The glass should then fall out.
  
  

Cutting the Replacement Glass

• 1). Trace the shape of the missing piece of glass onto the replacement glass. If the removed piece is not broken too badly, you can trace it with the permanent marker. If it is unusable as a template, trace the shape from the opening of the glass piece being sure to leave room for the thickness of the copper foil.
  
  
• 2). Score the new piece of glass along the marker line using the carbide glass cutter. Apply firm, even pressure without applying so much pressure that the glass breaks. Do not go over a previous score line.
  
  
• 3). Using the running pliers, which is a specialty wide-nosed plier for stained glass with rubber on the tips, break away the glass along the score line. You will break it in small sections. Break away the straight lines first and the convex curves, leaving concave curves for last. Nibble away glass in concave curves, making scores perpendicular to the curve line, if needed.
  
  
• 4). Smooth the edges of the glass using a diamond grinder. A diamond grinder usually has a table with a grinding cylinder in the center. Water flows over the surface of the table to keep the glass wet during grinding.
  
  

Replacing the Glass

• 1). Apply the copper foil to the edges of the new piece of glass. Make sure the foil is the same width as was used on the original piece. Press the foil over all of the edges evenly on the both sides. Make sure the foil is securely adhered all the way around the glass.
  
  
• 2). Brush flux onto the copper foil in a thin coat. Place the replacement piece into the opening made when you removed the original glass. Solder the piece in place using the soldering iron and wire solder.
  
  
• 3). Cover the foil with solder on one side and then allow to cool. Flip the glass unit over and repeat on the other side. You do not want to see any of the copper peeking through. When no more copper is visible, you are done. Allow the piece to cool before moving.