The reason why the soldering iron does not stick tin
1. The power of the soldering iron is too high
The power of soldering iron tips ranges from 20W, 25W, to hundreds of watts. Externally heated soldering irons have complex manufacturing processes, low efficiency, and high prices. Rapid-heating soldering irons are difficult to operate due to the large transformer in the hand. Internally heated soldering irons have a simple structure, high thermal efficiency, and are lightweight and flexible, so they are the first choice. For decoration of transistors, IC radios and televisions, and for ordinary circuit experiments, 20W is generally suitable. For repairing vacuum tube machines, such as tube amplifiers and old instruments, 35W is suitable, and external heating type is 45W. The wiring of the large transformer and the grounding trunk line on the metal base plate adopt internal heating type 50W and external heating type 75W. You can compare and see if the soldering iron tip you are using is too powerful.
2. Poor quality of soldering iron tip
There are some inferior soldering iron tips on the market. If you buy them accidentally, the problem of tin hanging on the tip of the soldering iron may easily occur.
Solution:
First prepare a blade and new solder wire, which should contain additives. First heat the soldering iron, then unplug it, use a razor blade to scrape clean the area to be tinned, and use a new solder wire to fill in the tin. It may still not go up at first. If it doesn't go up, scrape it clean and try again. When the temperature is lowered to a suitable temperature, the solder will naturally go up. If it still doesn't work, repeat the process. If it doesn't work, it means that your soldering iron tip contains too much tin and cannot be filled with tin. Just try it with a magnet and you will know.
3. The soldering iron is burned dry for a long time.
If the soldering iron is not powered on for a long time, poor quality solder and rosin are used, or the soldering head is not protected by tin before being left for a long time, the soldering iron layer on the soldering iron head is peeled off, resulting in the soldering head not being tinned.
Solution:
(1) Remove the power supply, remove the soldering head while the soldering iron is cooling (note: disassemble it gently and do not break the heating rod), and grind off the black non-stick tin layer on the prepared 1000-grit sandpaper. Of course, if sandpaper is not readily available, the fine sand surface of a household whetstone can also be used for grinding.
(2) Install the copper-colored welding head on the soldering iron and plug it in.
(3) When the soldering iron tip gradually heats up (be careful not to dip the soldering tip in rosin or absorbent sponge at this time), touch the soldering tip with rosin-core solder wire. From not melting at the beginning, when the temperature of the welding head gradually increases, the solder wire gradually begins to melt. At this time, after the solder wire touches all the copper-colored surfaces of the welding head, the solder can be hung.
(4) Dip the soldered welding head in rosin and it can be used.
