This is how it looks after a year or two:
When it is completely worn out, I simply wrap another one
When it is completely worn out, I simply wrap another one
Another trick: the tinned area of the tip tends to shrink with time, because oxidation progresses and charred deposits form a barrier too.
To regain the lost area normally requires careful scrubbing and progressive retinning with fresh solder, but it requires time and patience, and is not always 100% successful.
There are special formulations of flux supposed to address the problem, but they are not 100% reliable either, and can end with the opposite result.
I have found an easy, soft and effective manner of doing it:
You have to find a small copper tube of suitable dimensions, typically the ferrule holding the braid of a crimped connector.
With the iron cold, you clean thoroughly the area you want to retin until it is bright, uniform and shiny (don't scratch it!).
When it's done, you hold the iron in a vertical position in a vice and place the ferrule on the tip. You turn the iron on, at ~250°C and when it begins to reach the right temperature, you immediately melt fresh solder into the tube and on the tip.
When the tube is completely full, you leave to simmer for ~2 hours.
After that, you remove the tube and discover a beautiful retinned area: with time, and in absence of oxygen, the tin slowly creeps downard and covers all the enclosed area.
In difficult situation, you can activate the process by dropping a tiny pinch of aspirin powder (acetylsalycilic acid) in the tube before you add the solder.
Other activators are probably usable too, like borax, but I didn't test them
To regain the lost area normally requires careful scrubbing and progressive retinning with fresh solder, but it requires time and patience, and is not always 100% successful.
There are special formulations of flux supposed to address the problem, but they are not 100% reliable either, and can end with the opposite result.
I have found an easy, soft and effective manner of doing it:
You have to find a small copper tube of suitable dimensions, typically the ferrule holding the braid of a crimped connector.
With the iron cold, you clean thoroughly the area you want to retin until it is bright, uniform and shiny (don't scratch it!).
When it's done, you hold the iron in a vertical position in a vice and place the ferrule on the tip. You turn the iron on, at ~250°C and when it begins to reach the right temperature, you immediately melt fresh solder into the tube and on the tip.
When the tube is completely full, you leave to simmer for ~2 hours.
After that, you remove the tube and discover a beautiful retinned area: with time, and in absence of oxygen, the tin slowly creeps downard and covers all the enclosed area.
In difficult situation, you can activate the process by dropping a tiny pinch of aspirin powder (acetylsalycilic acid) in the tube before you add the solder.
Other activators are probably usable too, like borax, but I didn't test them
Sorry, I don't see what you mean. There is nothing galvanized in there, and NaCl shouldn't come close to a soldering tip, as it is corrosive at high temperature