Things You'll Need
Soldering iron or torch
When crafting a sculpture out of metal, there are two basic techniques for bonding pieces of metal together. One is welding, using an industrial arc welder or oxy-acetaline method; the other is soldering, using a small torch or soldering iron. Both techniques involve melting a piece of metal alloy to use it as a sort of metal glue that bonds the pieces together. For large scale pieces, you will need to use a heavy-duty welding method, but for smaller pieces such as wire and pipe sculpture, soldering is safer and less likely to damage the piece. Soldering materials and equipment can be purchased where plumbing, electrical and jewelry-making supplies are sold.
Clean the pieces that will be soldered. Solder won't stick to metal that is at all dirty or greasy, so do not skip this step. You can clean dirty pieces with dish soap and water; use an abrasive emery cloth to clean the joint. Do not touch the cleaned metal with your bare hands to keep it free of oils.
Clamp the pieces to hold them in place if necessary. Apply a small amount of flux, or soldering paste, to the joint with a small paintbrush.
Heat your soldering iron or light the torch as directed.
Apply heat to the flux using the tip of the soldering iron or the flame. The solder should start to turn translucent.
Hold the solder in the hand that you write with, with the end just over the fluxed area. Move the heated tip or flame to the solder. It will melt very quickly. Allow one or two drops to fall on the flux, then pull the heat away.
Adjust the piece with tweezers while the solder is melted if necessary. Solder cools quickly, so this must be done as soon as the solder drips. When the solder cools, the metal will be bonded.
Clean the flux from the cooled joint with a damp cloth.
If you plan to solder directly on a flat surface, lay the pieces on brick.
If you're crafting a sculpture out of silver, use a pickling acid to clean oxidation and flux residue.
Torches and soldering irons can cause serious burns. Follow all of the manufacturer's instructions exactly.