How to clean a stained whiteboard
Dampen a clean, paper towel with isopropyl alcohol. Only use a small amount, don’t completely saturate the paper towel, as you will want to use it sparingly. Too much can dull the surface of the whiteboard.
Never use water, heavy duty spray cleaners or detergents to clean a dry erase board. Water will destroy the finish, rendering the whiteboard unusable
Remove as much marker as you can with the eraser before you clean with the isopropyl alcohol. Gently rub the paper towel over the surface of the whiteboard to remove the marker stains. Flip the paper towel over, and add another small amount of the isopropyl alcohol to the other side if it starts to become dirty. Repeat the process using as many paper towels as necessary to remove the stains. Always work with a clean paper towel to avoid further smudging of the whiteboard with the old ink.
Dry the whiteboard thoroughly with another clean paper towel. Any left over alcohol that is left on the whiteboard will dull it, so be sure to remove it all.
Apply a small amount of wax to the whiteboard. Any type of car wax will do, I had some old turtle wax in the garage and it worked very well, but you only need to use a little. With a clean paper towel, take a small amount, and apply it over the entire surface of the whiteboard.
Buff the whiteboard with a soft cloth to ensure a slick surface for future use. Working in circular motions, wipe the cloth over the whiteboard to remove any excess wax. You will want to achieve a shiny, glossy like finish, without any excess wax remaining.
Use the whiteboard as usual with dry erase markers, and remember to wipe the surface with a felt eraser, following every use. “Rinse and Repeat” after heavy use or whenever staining becomes an issue. “Rinse and Repeat” was a joke in case you didnt’ get it, as that is what is says on most shampoo bottles…. hmmm do they really need to tell us that. Oh well you get the idea.
Hope that helps, it has worked many times for me and you can take an old whiteboard and make it look new again.