You may be familiar with the problem Apple is having with their newly released Home Pods and the white rings they sometimes leave on wood surfaces. Apple explains that they come from the vibration-damping silicone attached to the bottom of the Home Pods. “The marks can be caused by oils diffusing between the silicone base and the table surface.” Apple says the marks can be removed by wiping the wood with a soft damp or dry cloth.
My first reaction is how often people and companies talk about the “wood” when they are really referring to a finish that has been applied to the wood. And how silly this mistake sounds to us who know the difference.
My second reaction is how close this problem resembles what is known as “plasticizer migration.” In order to make plastics and lacquers, which are a type of plastic, more flexible (that is, less brittle), plasticizers, which are a type of oil, are added. When plastics are placed on a lacquer surface, especially under some weight, they can stick to the lacquer and sometimes cause it to turn white. The most common examples of this occur when small plastic disks are placed under lamps or other objects to prevent them from scratching the finish.
Plasticizer migration doesn’t happen with crosslinked finishes such as varnish, polyurethane and catalyzed finishes. I don’t think it happens on waterbased finishes, but I don’t know this for sure. I’ve just never seen it.
The worst case of plasticizer migration I have seen was on a lacquered dining table that had been covered with a plastic cloth for more than ten years. The lady had wanted to preserve the table for her daughter. The plastic cloth was so stuck to the finish that it took a lot of force to separate them and doing this, of course, damaged the lacquer to the point that the only option was to refinish. I was sad for the lady.
– Bob Flexner