Extending the Life of Soldering Iron Tips

By Ray Rayburn – A question from the Email Discussion Group.

“Is there something I should be doing to extend the life of soldering iron tips (I clean them after use, but that is it).”

Ray’s response:

I can’t speak to tips used on gas (such as butane) powered irons, but will address soldering iron tips in general here.

Way back soldering iron tips were made out of copper. Solder slowly dissolved some of the copper into the molten solder leaving pits in the tips. Therefore it was a common practice to file the tips to restore a flat surface.

Next came plated soldering iron tips. These were plated with either gold or more recently iron. As long as you did not scratch through the plating, and _never_ filed them these tips could last much longer than the old solid copper tips. The secret to long life with a modern plated tip is to always have a nice thick layer of molten solder over the tip whenever it is hot. When first heating up a modern soldering iron tip you _must_ be standing by with a roll of solder, and the moment the tip gets hot enough to start to melt the solder, give it a nice thick coating of solder.

What this does is to make sure the iron plating on the tip is never exposed to air when hot and therefore does not corrode. All that corrodes is the outside of the coating of molten solder, and you can treat the tip with a tiny bit of fresh solder, and shake off the excess, before you use the tip. If the tip is allowed to get hot before use and sit without solder applied for even a few minutes it may never be able to be “tinned” with a coating of molten solder. The solder will simply not stick to the iron tip if the tip has been allowed to corrode. Without a solder coating on the tip you will not get proper heat transfer to what you are trying to solder. Think of the corrosion as thermal resistance between the heat source (the tip) and the items to be soldered.

Flux is a chemical that cleans metal surfaces as it is heated and therefore promotes good solder connections. Never use any sort of acid or corrosive flux for electronic soldering. Flux will at times leave a hard crust on the iron tip, which can be cleaned by wiping the tip on a wet sponge. It is critical that as soon as the tip has been wiped on a sponge or other cleaning surface, that the tip be immediately be re-coated with fresh solder. The biggest mistake I see folk making that shortens the life of soldering iron tips is to wipe the tip off when putting the iron back in the stand. This is exactly backwards. Wipe the tip, if you must, when taking the iron out of the stand. When putting the iron back in the stand simply give it a bit of fresh solder coating. If you will not be using the iron for a few minutes and your iron is equipped with a dial-able temperature, consider turning down the temperature while the iron is idling.

Ray A. Rayburn – AES Fellow