Finish looks like “snake skin”

Q: I just had my oak kitchen floor refinished, completely stripped, restained with a single coat of poly applied. Everything looked fine at that point. Then we waited a few days to have the top coat of poly applied while other work was being done in my kitchen. After the final coat of poly was applied, I notice areas that the contractor described as “snake skin”.

The surface is perfectly smooth. In the daylight it is difficult to see any imperfection, but at night with lights on, there are plain areas where the floor has this “snake skin” look. Almost looks like many small bubbles, but without actual bubbles. The contractor came back in, soft sanded the finished coat, and reapplied another finished coat. Now the “snake skin” actually looks worse. I’m being told that they do not know what has caused this. Do you know the cause, and the resultant solution? Thanks.

A: I’m not certain what this is either, as you describe it. I’ve seen finish wrinkle and it looks like alligator hide (snakeskin finish?) This happens when a coat of finish is applied over a previous coat which has not fully dried. The solvent in the new coating etches into the previous coating and causes this “alligatoring”.