Hello there,
Family member had a plant in a jar on the windowsill over a longer period of time and over time (i guess while watering) water spillage has made its way under the jar and made quite the damage to the sill. Is there a good way to fix such a damage? Will obviously from now on have something underneath the jars to prevent this in the future.
Appreciate any tips!
It will depend on the material under the paint. Any particulate board you will probably want to replace. Wood can be dried, sanded and repainted depending on the depth of the damage.
But you will need to check the state of the material under the paint to know for sure.