Is there a varnish, with which one window frame – without stripping or sanding – can paint over?
Our answer: Use a ventilation reason, with. B. "Valve 1-2-3" from Glasurit. So you can do the first and second, possibly. do the third coat too. Then you don't need a primer. However, you cannot avoid sanding (Sandpaper grit 120 to 150), otherwise no paint will last permanently.