Soldering iron
Cordless irons can be heated by combustion of gas stored in a small tank, often using a catalytic heater rather than a flame.
Simple irons, less commonly used today than in the past, were simply a large copper bit on a handle, heated in a flame.
[1] Soldering irons are most often used for installation, repairs, and limited production work in electronics assembly.
Soldering irons were primarily used by tinsmiths and coppersmiths to work with thin sheet metal.
This led to the development of soldering irons that had a small copper tip attached to an inexpensive cast-iron block.
[6] By 1889, electric soldering irons were being developed with a resistance wire wrapped around the back end of the copper head and enclosed in a protective shell.
They started producing them and shortly after American Electrical Heater Company released their line of soldering irons.
[10][11] In 1946, Carl E. Weller applied for a patent for his soldering gun that could heat instantaneously and began production of the "Speedy Iron" in Pennsylvania.
In fact, within the patent, as a complementary description, it defines what today has become the "de facto", the redundancy is worth it, "form factor" of the vast majority of current Japanese and Chinese irons: Hakko, Baku, etc...
The now-expired patent, which even Weller has stopped using on some models, described an outer tube holding the coated copper tip, clamped with a nut to the handle.
[14] Located at the remote rear end of draw tube 26, and held thereto by peripheral flange 27, is a freely rotatable threaded nut 28 adapted to be threaded about nut receiving stud 29 of cover flange 21 to draw the tip 11 into proper engagementFor electrical and electronics work, a low-power iron, a power rating between 15 and 35 watts, is used.
[15] Some irons are temperature-controlled, running at a fixed temperature in the same way as a soldering station, with higher power available for joints with large heat capacity.
Simple soldering irons reach a temperature determined by thermal equilibrium, dependent upon power input and cooling by the environment and the materials it comes into contact with.
Another type of system uses a thermostat, often inside the iron's tip, which automatically switches power on and off to the element.
A hot knife is a form of soldering iron equipped with a double-edged blade that is situated on a heating element.
Most soldering irons for electronics have interchangeable tips, also known as bits, that vary in size and shape for different types of work.
[28] Older and very cheap irons typically use a bare copper tip, which is shaped with a file or sandpaper.
[citation needed] This dissolves gradually into the solder, suffering pitting and erosion of the shape.
[citation needed] Iron-plated tips may feature a layer of nickel between the copper core and the iron surface.
Exposed iron plating oxidises; if the tip is kept tinned with molten solder oxidation is inhibited.
Cleaning tips requires the removal of oxide without damaging the iron plating and exposing the copper to rapid corrosion.
It is recommended to work in a well-ventilated area; to avoid inhaling the toxic fumes; and to wash hands with soap after operating with a soldering iron.
[30][31] Sometimes, molten solder can "spit" or spatter, ejecting out from the wire and potentially causing damage to eyes and skin.
