Cleaning and maintaining soldering tips ensure its longer life. How to clean a soldering iron tip depends on the level of oxidation and contamination on its surface.
A soldering iron is the most important tool in any soldering project. It is a hand tool that provides heat to melt solder.
The three main parts of each soldering iron are:
heater
iron tip
handle
The majority of soldering iron comes with interchangeable soldering tips.
That way you can select the tip that is the best choice for the particular soldering project.
An iron tip should be replaced while the soldering iron is cold and not plugged in the power source.
An iron tip transfers heat to the solder joint. It consists of a copper core and plating. Copper is a metal that transfers heat very effectively, but it is very sensitive to oxidation. That is a reason why it must be coated with a layer of other metal to protect it from rapid oxidation.
Therefore, the working end of the iron tip is coated with the iron plating, and the rest of the tip is coated with another layer of chromium plating.
The biggest enemy of soldering iron is the oxidation of its tip. Someone may have a decent soldering station and may select a proper soldering tip for his application but if that tip oxidizes he will certainly have many problems making a proper soldering joint.
The oxidized iron tip does not properly transfer heat from the soldering iron to the solder joint.
When this happens, a beginner in soldering usually starts to increase the temperature of soldering iron hoping that setting soldering iron to a higher temperature will solve the problem.
However, this makes the problem a lot worse.
Besides corrosion, the iron tip should be cleaned from excess solder since the old solder can’t be re-used and won’t flow to the solder joint.
Also, the rosin flux will corrode the iron tip if left on it for some time. The majority of today’s solder wire contains a rosin flux in its core. Rosin flux is used to clean metal surfaces to be soldered and to prevent oxidation of those surfaces during the soldering process.
Whether your soldering iron is a simple pencil style or fancy temperature-controlled soldering station, electric or battery-powered, it is important to take proper care and maintenance of iron tip.
There are a few different ways to clean soldering iron.
Small contamination and oxidation on the iron tip can be cleaned by wiping a hot iron tip on the moist soldering sponge.
You should wipe all surfaces of the iron tip.
A quick wipe is good enough to remove oxidation. Don’t place soldering iron on sponge longer than it is needed.
You may hear some hissing noise when the hot iron tip touches a damp sponge.
Wiping the iron tip on a moist sponge usually lowers a little bit the temperature of soldering iron but a majority of soldering iron will recover in a few seconds. Just allow a few seconds after cleaning the iron tip (with a moist sponge) for the iron to reheat.
Soldering sponges are heat-resistant and treated with chemicals to prevent tip corrosion.
Use distilled water on soldering sponge since regular tap water contains minerals.
Minerals will cause oxidation of the iron tip.
When the sponge gets dirty replace it with a new one.
You may use a non-abrasive brass wool tip cleaner (or similar product with aluminum wire) to remove contamination from the tip.
Quickly insert hot soldering iron into coils of brass wool tip cleaner and twist it few times.
This will remove oxidation from the iron tip and leave a thin layer of solder on the surface of the iron tip.
If the iron tip is heavily oxidized then you should clean it with a different technique.
Before you turn on your soldering iron and while your iron tip is cold use a small fine bristle brush to remove loose particles, rust, and contamination.
Don’t push hard to remove oxidation.
Never use a steel brush since you may damage the plating of the tip.
Then use a polishing bar to remove stubborn black oxides on the surface of the tip. Use only those polishing bars that are recommended by the manufacturer of the particular soldering tip. Gently rub the iron tip on that polishing bar. That will rub off the oxidation and it won’t remove the plating from the tip. Don’t push soldering iron hard on the polishing bar.
In severe cases, you may use a tip tinner. While soldering iron is hot, dip it in tip tinner and move it around. This will remove oxidation. Use this method cautiously since if you use it a lot and too often then it may damage the plating of the tip.
You should clean all working surfaces of the tip. A chisel tip has two sides, so both sides should be cleaned. A conical tip is round so rotate the tip while you rub it on the polishing bar or brass wire tip cleaner.
Never use sandpaper or file to remove oxides from the iron tip. They will remove the plating of the iron tip and exposed the copper core of the tip to corrosion.
Put soldering iron back in the iron holder and turn it on.
Now, immediately after cleaning, the soldering iron should be tinned.
Make sure your iron tip is always clean so repeat cleaning and tinning soldering iron as much as needed. If you maintain properly your soldering tool, you will extend its life. Technicians clean iron tips constantly, typically every couple of solder joints.
When you plan to make a longer break turn off your soldering iron. This will minimize oxidation of the iron tip and therefore less cleaning of the iron tip will be required.
Cleanness is one of the main requirements for a successful soldering job. Reliable solder joints and proper wetting can only be accomplished with completely clean surfaces.
Besides a clean iron tip, both metal surfaces to be soldered should be clean as well. Any corrosion, coatings, dirt, or other contamination on the solder joint will form a barrier to the proper flow of heat. Then even though you are using good soldering iron it may not be able to supply enough heat to melt the solder and make a good soldering joint.
A quick preparation before the start of soldering will result in the perfect solder joint:
Use isopropyl alcohol to clean surfaces from contamination
Apply a small amount of flux paste to solder joints prior to soldering