In article ,
Cydrome Leader wrote:

What happens if you use regular solder on something that was originally
lead-free,
or you get the lead free solder on a regular iron?

I understand manufacturers keep separate lines as mixing the two is bad, but
what
about in the repair world?

Does lead free solder mess up good quality tips or anything like that?

CL-

One problem occurs if you use leaded solder on surface-mounted
components. Lead amalgamates with the silver that is "fired" onto these
components, ruining their electrical connection.

I've read that a lead-contaminated solder iron can cause the problem
even if lead-free solder is used. I've never heard of the opposite case
with lead-free solder.

To be safe, I keep two sets of equipment.

Fred