Types of Solder

• The most common type of solder is of the tin and lead variety, designated by two numbers that identify the amount of each metal present. The first number indicates the percentage of tin, while the second designates the amount of lead. The most common tin and lead combinations for stained glass work include: 60/40, 50/50 and 63/37. Lead-free solders are also used; these contain silver or copper along with tin. Lead-free solders for stained glass work do not use numbers to determine the type, and manufacturer specification sheets should be consulted to determine metal percentage, as well as melting and cooling points.
  
  

Working Range

• A solder's working or "pasty" range is the interim temperature of the molten solder as it transitions from its molten to solid state. The pasty range is an important consideration when choosing solder, as it will determine the available working time to make minor adjustments to the glass, and to the ability to create a uniform solder line called a "bead." Although the working range of solder is a key element to its successful use, operator skill and craftsmanship are essential to taking advantage of this attribute.
  
  

Attributes of Solder

• Properly done, solder joints can last for many years. Solder is relatively inexpensive, easy to work with, and can add to the beauty of the finished piece. Because solder is a metal, it can be polished or left alone to eventually attain a natural patina pattern. Remedy mistakes by remelting the solder and correcting the error, and make repairs or restorations by re-melting the original solder or creating new joints.
  
  

Flux

• Flux is used along with solder to remove contaminants from the surface to be soldered, and to prevent the metal in solder from oxidizing. In stained glass soldering, flux is brushed onto the surface before soldering. While most of the flux will evaporate during the soldering process, any residue is simply wiped away. Liquid flux is the most common type for glass soldering, but paste or gel fluxes are sometimes used.
  
  

Using Multiple Solder Types

• Using different types of solder on the same piece can add decorative elements and structural integrity. Solder with a high melting point, such as 50/50, is often used on the back of the stained glass work. On the front, a lower melting point solder such as 60/40 may be used with no danger of remelting the back solder joint. A fast working range solder such as 63/37 may be used on top of the 50/50 or 60/40 to add three-dimensional designs over the underlying structural solder joint.