Doest this soldering thing fix the problem completely? So the tank works as it should?
Maybe. I soldered mine, but also filed down the insulator. I don't have the tool to measure it, but it seemed the pin wasn't reaching down enough so I had a guy shave it down and then soldered it. It's been working ok, but not so well in TC. My other two work great in TC.
If the paint is truly the culprit, then removing the paint is an option. I was able to scratch some off, so it will come off. Strip it down and it should work. I tried to remove the paint from the well/chimney part, but it doesn't seem to be painted. I don't know how it's done, but I bet it will come off the base section. I haven't done mine because it's working. If it does stop, then I'll strip it down. I've learned I don't like black tanks. It's much harder to see the JFC.