Often, we get the question what we are using for cleaning our soldering iron tips? Or receive criticism for using either. There seems to be a big divide between ‘steel wool’ and ‘sponge’ people. Here's what we use and why.
The good old trusty wet sponge with nice smoke and sound effects when trying to clean the tip of the soldering iron. The problem of the ‘steel wool’ people is exactly that. You're pushing your hot soldering tip into a wet sponge, cooling it down which solidifies the solder, capturing most of the dirt. Also the tip gets engulfed in water vapour filled with chemicals which corrodes away your soldering tip.
We completely agree with this; when using the sponge incorrectly. The sponge is not meant as a water bath. It’s meant as a cleaning method. Often people use way to much water. The sponge should be slightly moist, not dripping with water. Second, the soldering tip should be wiped across the surface, not buried deeply within the spongy material. The cooling effect aids in desolving excess solder from the tip, and the little amount of smoke helps remove flux residue. Don’t forget to check and re-tin the soldering tip! Otherwise, your tip can be in trouble, especially when you don’t immediately start soldering again.
We also find this a good cleaning solution. The steel wool has less thermal mass as the water contained within the sponge. This aids in not removing as much excess solder from the tip, but leaving the tip tinned. Although the abrasiveness of the steel wool slightly aids in removing excess solder. The abrasiveness really comes to play in removing hard to remove flux residue and dirt that comes from reworking an older PCB.
It also has it’s down sides. The abrasiveness can wear down your soldering tips quicker, depending on the base material of the tip and it’s coating. Your steel wool can become dirty, as can your sponge. But you can simply rinse off the sponge under a running tap with a little drop of detergent. Cleaning the steel wool is not that easy, often it is easier to just replace it. While the sponge can almost outlive you, when used correctly and cared for. Also fluxing your steel wool now and then can be mandatory to get good results from it, something that is not recommended with the sponge.
Both steel wool and the sponge are good methods for cleaning your soldering tip. While steel wool is more ‘foolproof’, the sponge has benefits too. We use both. We prefer the sponge for our older irons such as our Weller LR21 and DS80, and when using a speciality uncoated soldering tip. We prefer the steel wool when reworking lead free PCBs. When reworking older, like in pre to mid 80s, PCBs and especially dirty PCBs, we use both at the same job. First we clean most of the hard to remove stuff on the steel wool. And then we thoroughly clean the rest with one or two swipes over the sponge.
But above all, remember there’s no ‘only correct way’. What is good for you depends on your type of work, equipment, workflow and skills.