I am in the process of painting my bathroom side sliding wood window. (circa 1968). I have 3 more of these to do in a couple other rooms. The windows do all open and are in very good condition, but, they are starting to stick on the metal track. Does anyone have a suggestion of what to put on the metal track, to make the windows slide easier. I looked online, and one place said to use candle wax. Another place said, not to use candle wax, because it freezes in the winter, but to use bar soap, because the oils in the bar soap, do not freeze, so I am uncertain, what to do.

Thanks

Cat