stylistic:tone, structural:summarization
Heating methods

Different types of soldering tools are made for specific applications. The required heat can be generated from burning fuel or from an electrically operated heating element or by passing an electric current through the item to be soldered. Another method for soldering is to place solder and flux at the locations of joints in the object to be soldered, then heat the entire object in an oven to melt the solder; toaster ovens and hand-held infrared lights have been used by hobbyists to replicate production soldering processes on a much smaller scale. A third method of soldering is to use a solder pot where the part (with flux) is dipped in a small heated iron cup of liquid solder, or a pump in a bath of liquid solder produces an elevated "wave" of solder which the part is quickly passed through. Wave soldering uses surface tension to keep solder from bridging the insulating gaps between the copper lines of flux-coated printed wiring boards / printed circuit boards.

The electric soldering iron is widely used for hand-soldering, consisting of a heating element in contact with the "iron" (a larger mass of metal, usually copper) which is in contact with the working tip made of copper. Usually, soldering irons can be fitted with a variety of tips, ranging from blunt, to very fine, to chisel heads for hot-cutting plastics rather than soldering. Plain copper tips are subject to errosion/dissolution in hot solder, and may be plated with pure iron to prevent that. The simplest irons do not have temperature regulation. Small irons rapidly cool when used to solder to, say, a metal chassis, while large irons have tips too cumbersome for working on printed circuit boards (PCBs) and similar fine work. A 25-watt iron will not provide enough heat for large electrical connectors, joining copper roof flashing, or large stained-glass lead came. On the other hand, a 100-watt iron may provide too much heat for PCBs. Temperature-controlled irons have a reserve of power and can maintain temperature over a wide range of work.

A soldering gun heats a small cross-section copper tip very quickly by conducting a large AC current through it using a large cross-section one-turn transformer; the copper tip then conducts the heat to the part like other soldering irons. A soldering gun will be larger and heavier than a heating-element soldering iron of the same power rating because of the built-in transformer.

Gas-powered irons using a catalytic tip to heat a bit, without flame, are used for portable applications. Hot-air guns and pencils allow rework of component packages (such as surface mount devices) which cannot easily be performed with electric irons and guns.

For non-electronic applications, soldering torches use a flame rather than a soldering tip to heat solder. Soldering torches are often powered by butane and are available in sizes ranging from very small butane/oxygen units suitable for very fine but high-temperature jewelry work, to full-size oxy-fuel torches suitable for much larger work such as copper piping. Common multipurpose propane torches, the same kind used for heat-stripping paint and thawing pipes, can be used for soldering pipes and other fairly large objects either with or without a soldering tip attachment; pipes are generally soldered with a torch by directly applying the open flame.

A soldering copper is a tool with a large copper head and a long handle which is heated with a small direct flame and used to apply heat to sheet metal such as tin plated steel for soldering. Typical soldering coppers have heads weighing between one and four pounds. The head provides a large thermal mass to store enough heat for soldering large areas before needing re-heating in the fire; the larger the head, the longer the working time. The copper surface of the tool must be constantly cleaned and re-tinned during use. Historically, soldering coppers were standard tools used in auto bodywork, although body solder has been mostly superseded by spot welding for mechanical connection, and non-metallic fillers for contouring.

During WW2 and for some time afterwards SOE forces used small pyrotechnic self-soldering joints to make connections for the remote detonation of demolition and sabotage explosives. These consisted of a small copper tube partially filled with solder and a slow-burning pyrotechnic composition wrapped around the tube. The wires to be joined would be inserted into the tube and a small blob of ignition compound allowed the device to be struck like a match to ignite the pyrotechnic and heat the tube for long enough to melt the solder and make the joint.