I have been using a Weller WLC 100 for about 10 years, and I have always used this conical tip from Apex Tool Group: https://www.mouser.com/ProductDetail/apex-tool-group/st-7/?qs=fKX4t1ubQE95bthTEmHMHA%3D%3D&countrycode=US¤cycode=USD
Recently I have been using tin/silver/copper (Sn96.5Ag3Cu0.5) lead free solder -- I've been using this solder: https://www.digikey.com/en/products/detail/multicore/796065/2498924
I am able to use a new tip and this solder for about 3 - 4 months before the tips become dull and grey and no longer have solder cling to them. After that, they will melt the solder, but the solder will ball up and just fall off.
From reading other posts here, it appears that perhaps I am cleaning the tip too abrasively and removing the iron plating. For instance, my soldering routine is:
- Turn on iron/let solder previously left on tip become molten
- Wipe off molten solder on damp sponge
- Do soldering
- When tip appears to be dirty, wipe it off on a sponge
- When tip appears very dirty, pull it through my copper scouring ball
- When soldering done, cover tip in solder
- Turn off iron
I think on step #5 above, I may be damaging the tip. On the other hand, when I use leaded solder I don't have any problems, and I have use the copper scour ball for a long time with no issue.
I have also written to Weller and they could not make any suggestion about why my tips were ruined.
Attached is an image of my soldering station, which can only control temperature by potentiometer (I keep knob just below 5 as that appears to melt solder easily, and a bit below takes solder too long to melt). Also attached is an image of two "dead" tips.
- Can anyone suggest why my tips become dull when I use this lead-free solder, and why solder will not cover them any more?
- Is it possible to re-tin my tips? If so, how?