With the different types of finishes available today, we first need to find out if we are dealing with a urethane coating, wax, penetrating oil, or a hard wax oil.
Applying mineral spirits to a white rag and rubbing a spot on the floor usually will start breaking down a wax or penetrating oil. It will reveal itself as a glaze on the rag or it will start absorbing the color into the rag. This process will not affect a urethane coating and will show nothing. Some of the penetrating oil companies provide cleaning and recoating products that also can help test for the presence of penetrating oils.
After identifying the type of finish, we then need to understand their maintenance procedures. Many products can hinder the bond of a new coat of finish. One floor care product to test for is an acrylic polish. Test kits are available to test for this. If present, it must be removed before attempting a recoat. If no polish is present or if it has been completely removed, most deep cleaning and recoating systems/procedures can remove other possible contaminants.
If the homeowners do not know what finish is on their floor and you are called upon to apply a maintenance coat, the most important thing to check for is if it has wax or other contaminants that may affect the finish you want to apply. If the floor has been waxed, then the best bet is to re-wax or re-sand.
Typically, when an existing client calls for wood floor maintenance, we will look up their file to see what type of finish we have used on the floor. Based on that information, what we will recommend to the client is the proper protocol for maintenance in that situation.
If the client is new, a site inspection is required. We may bring some cleaner, paint thinner, as well as finish to determine what is on that floor. After a visual inspection, we will try our cleaner first to see if that removes the dirt the client was worried about. We may use the paint thinner with a white cloth to see if it is some sort of hard wax oil finish. Then we’ll recommend the proper cleaner.
We also have simply used a spray bottle of water to see if it beads up like water in oil to determine if it is an oil/hard wax finish. Sometimes we will put some blue tape on the floor in a discreet location to see if any finish is removed when we pull the tape off.