I'm trying to add some solder to solder points of SMS legs on a PCB but it just isn't taking the solder. The solder seems to keep bubbling up. Any advice?

 

hi John,
Is the solder Lead free, also liquid flux will help.

E

 

hi John,
Is the solder Lead free, also liquid flux will help.

E

Yes it's led free solder. I will try some flux

 

I might also clean with some alcohol. Preferably 90-100%.

 

Lead free doesn't solder as readily as leaded so get some containing lead if you can.
There is absolutely no health hazard from using leaded solder.

 

Try increasing the temperature of your soldering iron to 800°F or 425°C and use tin-lead solder to get it flowing.

 

Try scrubbing the pad with a "rust eraser" pen (has a bundle of stiff fiberglass bristles, got mine from the auto parts store in the autobody section). Maybe there's some oxide layer that prevents solder sticking.