Desolder a crystallised solder joint

[_ar_]

Hello All,

I have a PCB with battery acid damage. I tried to desolder the battery pack and managed to do so for the 2 + terminal. However the - terminal's solder joint got the biggest hit from the battery. I just could not flow the solder no matter what I tried: used higher temperature, use a solder sucker, flooded the area with flux from a fluxpen, tried to heat both sides of the joint. Also tried to reflow the joint, but the solder barely melted, I could move it around somewhat and it would not take fresh solder. I ended up cutting the terminal. What is the best way to deal with such joints?

Thanks,
_ar_

[jmelson]

Dilute the solder with fresh solder, preferably SnPb or low melting point solder.  Possibly, somebody soldered it with high melting point solder in the past.  The fresh tin-lead solder should lower the melting point enough to make it possible to disassemble it.

Jon