5 Rules for Successful Soldering

What is soldering?

Soldering is the process of joining two pieces of metal with solder, an alloy of silver, zinc and other trace metals. The solder is heated to a molten state and then forms a strong bond between two metals as it cools back to solid form. Once you understand the basic rules of soldering, the process will begin to fall into place.

These 5 Rules for Successful Soldering will help you to understand the process and succeed at soldering.

Rule #1. Metal must be clean.

Solder won't flow on a dirty or greasy surface. Make sure that the metal is clean before soldering. Clean your metal by giving it a quick scrub with a non-bleach cleanser like "Bar Keepers Friend", metal cleaner like "Penny Brite" or place it in your pickle pot and let sit for a few minutes. Rinse all pieces thoroughly under running water and dry with a clean soft cloth.

Rule #2. No gaps in the seams.

All seams must fit must fit tightly together. Solder will not flow to fill a gap in the metal. Avoid ill-fitting seams by cutting using smooth edge metal shears, appropriate saw blade, or a flush wire cutter depending on the material. Files are commonly used to perfect cut edges before soldering.

Rule #3. Use flux for prevent firescale and help the solder to flow.

If using wire or sheet solder, apply flux to all areas to be soldered. Flux allows the solder to flow and connect the join during the soldering process. Flux also prevents oxidation of the metal surface during soldering. Paste solder does not require the use of flux, but you may apply it, if desired, to aid in the prevention of firescale.

Rule #4. The heat of the metal causes the solder to flow.

When soldering, the metal must reach the necessary temperature in order for the solder to flow. Remember that it is the heat of the metal and not the flame of the the torch that heats solder to the flow point. Concentrate the heat first on the surrounding surface, then on the join to be soldered. Heat all parts of the piece evenly. The solder will flow to the hottest part of the surface and move with the heat of the flame.

Rule #5. Clean your piece between steps.

Pickle removes fire scale caused by the heat of the torch. Use a small crock pot to keep pickle warm. To mix pickle solution use about 1 cup of water to 1/8 cup granular pickle and mix. Your soldered piece must be pickled in between each soldering step. Only use copper tongs in the solution, as steel tools will contaminate the pickle.

In case of soldering failure, pickle the piece, review these steps and start again at the beginning.

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