Stained glass artists are concerned with the mechanical and the artistic factors. From years of experience, I have accumulated some tips I think every stained glass artist should keep in mind.

The Solder Alloy In any soldering procedure a mechanically reliable joint is essential, but for Stained Glass work the appearance of the completed joint is also vitally important.

1). The solder joint must blend into the shape of the material being soldered. 2). The surface of the completed joint must be smooth and free of any bumps or grittiness. 3). As the solder oxidizes from exposure to the air, or the application of any metal coloring agents, the fillet should develop the same patina as the remainder of the metals.

What is the easiest to use? The standard 63/37 tin/lead alloy remains the easiest solder to use. It melts at 183C and has no pasty phase, changing directly from solid to liquid and back to a solid. This means that the solder solidifies instantly producing a very smooth fillet, with no ridging or other marking which may be caused if the joint moves during solidification.

Looking for a lower cost? When cost is a major concern, solders with a lower tin content can offer some savings.The 60/40 alloy produces almost similar results at a slightly lower cost. However, there are pros and cons to this type of alloy. The 60/40 alloy has a slightly higher melting point and a small pasty phase. As the tin content is reduced, the solders have a higher melting point and as they cool, they pass through a pasty phase. This can produce a frosty appearance to the solder fillet and of course will leave striations or cracks if the joint moves during cooling. The higher meting point also means that soldering has to be carried out at a higher temperature.

In general, the 63/37 eutectic tin/lead solder is easiest to use and produces a better looking joint. Solders with a higher proportion of lead are cheaper but less forgiving.

What about lead-free solders? Several lead-free alloys are available, and are similar in performance to the lower tin content solders mentioned above. With normal care, there is little or no jeopardy to the operator in the use of lead bearing solders. Their chief environmental threat lies in the disposition of scrap metals which should always be returned for recycling.

How to Select and Use the Soldering Iron Buy an iron with a chisel bit, as large in diameter, and as short as is convenient to use. If you will be soldering many joints at a time make sure the iron wattage is sufficient to maintain a constant temperature. The tip should stay at least 100C above the solder melting temperature during the entire soldering process.

Ideally the iron should always operate at the same temperature. This is almost impossible to achieve, as the moment the tip touches the joint the temperature begins to fall rapidly. With an uncontrolled iron this means you will be soldering at varying tip temperatures. Minimize the variation by using a reliable temperature controlled soldering iron.

The Patina Make the joint quickly and try to avoid a "second soldering". The objective must be to use the right iron and the right technique so that the joint is made correctly the first time with the solder flowing smoothly into the overall shape of the design. When this can be achieved and the solder is made from clean, pure base metals, there is seldom any problem in developing an excellent appearance.