Spilled soldering flux

[ezdays]

Liquid rosin flux should dry hard enough that you might be able to scrape off a lot of it but it could remain sticky for a while before drying hard. One thing that cleans up rosin flux is acetone, but then you have to be careful of getting it around some plastics. If you want to try to paint over it you might try putting on a primer first. When we had our business, we did a lot of soldering, PC boards, wires and even some connectors, and we used flux that was water soluble. Cleanup was easy, just rinse away the flux with water and a brush. I kept some of it and also solder with water soluble flux, and that's all I still use.