Why does the tin always adhere to the soldering head when using an electric soldering iron?
If the welding head of the electric soldering iron does not eat tin, the tip of the soldering iron will soon be oxidized due to high temperature. Commonly known as burnt to death! After oxidation, the tip of the soldering iron turns black, and it is quite difficult to melt and solder first! You will find that the temperature of the old iron is very high, and even small debris can cause sparks! But the solder can't be hot! So the soldering iron tip must retain a layer of tin film to protect the soldering iron tip from oxidation. When welding, the heat can be transferred out in time to ensure the welding quality.
And you said that there will always be excess solder on the tip of the soldering iron, which is also a normal phenomenon. When soldering, the melted solder will always flow from the place with low temperature to the place with high temperature. So we can take advantage of this feature. When repairing the circuit board and removing parts, use a soldering iron to suck away part of the solder on the original pins. Of course, it will be better to use a tin absorber and a tin absorber to remove the solder.
After the soldering iron tip absorbs excess solder, we can use the method of shaking the soldering iron gently, and use inertia to shake off the excess solder on the soldering iron tip. Generally, dip the soldering iron tip in rosin, and then shake your wrist quickly , Throw the solder into the rosin box. And when we want to eat tin for the original pins, or tin for the wires, or solder the originals on the circuit board, we can use the tip of the soldering iron to eat solder in the rosin, and directly eat tin or solder for the original pins to make up for it. welding etc.
When using a soldering iron, pay attention to the following points:
(1) Check wiring and insulation. Before using the soldering iron, check whether the power wiring is correct and whether the insulation between the shell and the heater is good, so as to avoid loss or electric shock.
(2) Tin on the tip of the soldering iron. The new soldering iron tip must be tinned before use. First, use fine sandpaper or a fine file to remove the oxide on the tip of the soldering iron tip, and then heat it with electricity. When the soldering iron tip turns from purple red to purple brown, apply a layer of rosin, and gently rub the solder wire on it, so that the tip of the soldering iron tip is coated with a thin layer of solder. The solder should be applied evenly. If some parts do not eat tin, it means that the place is not clean. At this time, it should be re-tinned according to the above method.
After long-term use of the soldering iron tip, the original flat shape will change. At this time, the pin should be unscrewed, the soldering iron tip should be taken out, and the original shape should be refiled with a file, and tinned.
(3) Temperature regulation. The temperature of the soldering iron tip should be appropriate. When the temperature is too high, it is easy to oxidize and turn black, which affects tinning; if the temperature is too low, it is not conducive to the melting of solder and affects the welding quality. Adjusting the temperature of the soldering iron tip can be achieved by changing the length it protrudes. The longer the length of the soldering iron tip sticks out, the lower the temperature; conversely, the shorter the sticking out length, the higher the temperature.
(4) Welding method. The type of electric soldering iron should be reasonably selected according to the size of the weldment, and a high-power electric soldering iron should be used when the workpiece is large. Before welding, use sandpaper or a steel file to polish the welding part of the workpiece and expose the clean metal surface. After dipping the preheated soldering iron tip with rosin (this step can be omitted if the solder wire has rosin inside), remove it. To the welding position, add solder wire to weld it firmly (solder should not be too much). For larger workpieces, the welding surface can be heated in advance, and if the welding is not good at one time, it can be welded several times. The reason for poor soldering is mostly that the soldering surface is not clean or the soldering temperature is low. At this time, a high-power soldering iron should be used instead.
(5) Pay attention to safety. When soldering, the electric soldering iron should be handled with care, and knocking should not be avoided. If there is too much solder on the tip of the soldering iron, it should be scraped off slowly and not thrown around. When not in use temporarily, it should be placed on a soldering iron stand, or placed in a place where there is no heat transfer. Do not place it randomly to avoid scalding other items. When not in use for a long time, the power should be cut off to avoid excessive oxidation of the soldering iron tip. Usually, the electric soldering iron should be placed in a dry place to prevent premature corrosion of the heating resistance wire.
