After mentioning how much I like using a brass sponge when soldering, I came across this App Note from OK International. This is a great note to read through. It discusses what is inside of a soldering iron tip, why they fail, and how to keep them in good shape.
![Layers of a Soldering Iron Tip](https://www.baldengineer.com/wp-content/uploads/2015/01/Screenshot-2014-12-29-22.28.52-300x222.png)
The note actually makes me realize two of my own mistakes.
First, most cleaning should be done with a wet sponge not the brass sponge. (Oops!)
Second, pre-made tip tinners are meant for occasional cleaning. Moving forward I think I’ll modify my soldering behavior so that I start with a quick clean in the brass, use the sponge while working on a board, and then use standard solder to protect the tip when done.