Cleaning a new commercial job today and they asked me to clean their sign as well as the windows. The sign must have had water dripping on it from above as it was stained with water marks. I told them that pure water will most likely not remove the stain, and alas it did not.
I said i'd try to get a chemical that will remove it next time I do the job.
Does anyone know of anything I can put on the brush that will remove the stain?
The sign itself looks to be made of some sort of black plastic with a very glossy finish so I don't want to use anything that will damage it.