ESC Solder Wont Stick

[D.O.G.]

I've been using the same soldering gun and solder from Walmart. I had no problem in the past soldering wires, not the greatest, to the pads of a esc, motor and so on. This time I have a 4in1 esc that for some reason I can't get the solder to stick on this esc. I was wondering if there some sort of coating on the pads. Can I clean the pads with something like rubbing alcohol. I can't finish up my 4" twig if nothing wants to stick. Any ideas will be appreciated.

 

[Tony]

You can use alcohol to clean the pads, and try using some flux on the pads before trying to apply the solder. I always suggest flux for the cheaper soldering irons because it helps get the heat into the pads for them to tin correctly. It will smoke, a lot, but worth it.