Any metallurgists on the forum?

[Lawrence]

Was chatting to a chap at a show recently and we got to talking about soldering. When it came to tip cleaning he preferred the scrubber ball whereas I always go for the damp sponge (the RAF taught me that way)
His assertion was that applying a hot tip to a damp sponge caused micro fractures in the tip and the best way to clean a dirty tip was his method.
Now generally, by using the sponge method, my tip never gets so dirty that I have to use the metallic scrubber stuff, but does he have a point regarding a hot tip even when applied to a room temperature, damp (not wet) sponge?
Metallurgists it's over to you 

[jpendle]

I'm not a metallurgist, but in my day job I frequently visit PCB assembly plants and the repair techs at most of those have the metal scrubber tip cleaners.

As a matter of fact I'm just about to fly off to sunny San Francisco and visit one this afternoon.

Regards,

John P

[Malc]

I generally use a damp sponge and have done for 40+ years. I've only had issues on the old copper bits that develop a hole in the end. I never have had a problem with the more modern steel coated copper tips.

[JanW]

I'm no metallurgist but Google helps 

https://www.weller-tools.com/how-to-care-for-soldering-iron-tips/
Recommendations from a well known manufacturer.

Jan

[Newportnobby]

Interesting about their comments about damp sponges yet they supply a sponge in the WHS40 temperature controlled station I have

[themadhippy]

spit an jeans has kept my antex iron tips going for years

[The Q]

I work for a major electronics manufacturer, and our soldering irons have either, though the newer the iron the more likely it will have the brass not the sponge. All the older wellers have sponges..