If you don’t know the cleaning or maintenance history of the floor you want to recoat, STOP!
Here’s why: if that floor has been cleaned with Murray’s Soap Oil, Orange Glo, or any acrylic waxes like Future or Mop & Glo, a modern polyurethane will NOT bond to it. Even if you screen it aggressively first, you are likely to experience “crawling,” the dreaded “fish-eye,” or just widespread peeling after the finish is applied. *shudder*
There are two types of products you need to test for to determine if you need to chemically strip the floor before recoating.
Grease-based residue, like wax or oil-soap.
Acrylic waxes or polishes.
Here's how it works...
Testing for grease-based residue, like wax or oil-soap
1. Choose a low-traffic area that has been cleaned thoroughly. Behind a door is a good spot because this area is usually cleaned or coated but wears off slower (by contrast, closets and pantries are not good test areas because those areas are often skipped during the cleaning process).
2. Next, place several drops of mineral spirits (a.k.a. paint thinner) and let them sit for 2-3 minutes on the flooring section.
3. Wipe up the paint thinner with a clean white rag. If you see brown or yellow residue on the rag, or if the residue feels waxy, a contaminant is present. Scrub the entire floor with a small amount of paint thinner and steel wool (buffers are good for this) until all residue is removed.
Testing for acrylic waxes or polishes
1. Find a low-traffic, thoroughly cleaned area (as we mentioned before, behind a door is a good option).
2. Place a large drop of a 1:1 water-ammonia mixture on the floor and allow it to sit for 5-10 minutes.
3. If the area turns white, a floor polish or wax is likely present. Scrub the entire area with a 4:1 water-ammonia solution until all residue is removed.
Although this means a few extra minutes of work for you, you do NOT want to skip these steps. Unless you personally have been in charge of cleaning and maintenance of this floor for a good long while, you don’t want to risk recoating over all this gunk.
Check out our 10 Commandments of Hardwood Floor Maintenance for more on caring for your floors.