Once you have brushed yourself out the door in a pre-planned route, let this second coat dry at least 40 hours. It will have been applied at the rate of about 500 -600 square feet to gallon. Keep track of how much finish you are using, too thin a coat, and you won’t have enough build of finish to protect the wood. Too much and it will never dry properly. And that’s the rub, this second coat has to dry well enough so that again, when scuff sanded (or screened with the buffer) the sandpaper or screen doesn’t clog with bits of undried finish. In some cases in the middle of summer I cease to use OMP at all. I take most of August off and go fishing. In temperatures exceeding 80 F and humidity exceeding 75% OMP will just sit there like a pool of undried oil. What a mess that will be. This often happens on older floor that have been waxed or treated with various silicone or oil polishes.
The screening of the second coat is very critical step. You must not only scratch all of the floor surface, but all the little dust bits and bubbles that occurred in the second coat must now be buffed out, even if you have to sand some spots by hand. This is your last chance. Vacuum as before and tack rag, and be even more diligent when coating the floor this time, don’t miss a spot, or create a blob in the finish. We used to call these holidays and silver dollars. My boss used to yell out the door as we were leaving the shop in downtown New Orleans. “By god, Boys, leave no holidays or silver dollars in the finish today”. But if you got them in the third coat, either live with the silver dollars, or sand them flat and touch them up. You have to re-coat the entire board otherwise the finish edge will show.
Now, if you have followed my instruction to the letter and have used the Fabulon brand heavy-duty polyurethane satin finish, you will now have an almost bubble free floor. The only defects in it are so minor, that after a month or two they are abraded out of the top of the finish.
If on the other hand you have used only half my methods, and strayed into your old bad habits, rushing through the job, to get paid, or for the DIY ‘ers just to get life back to normal, your results will be something less that spectacular. But I have a few more hints. Wear a hat when coating (we hate to see hairs caught in the finish), and be sure to wear clean clothes the day of the second and third coat. Ventilate all coats with a large fan about 4-5 hours after the finish is applied (or when the surface is hard enough not to have dust stick to it). You only need to clean the brushes when done with all coats, in the mean time keep them cleaned with paint thinner but wrapped in a thinner soaked rag. When you have completed the job, clean the brush until the thinner runs clear off the brush (that’s what the roasting pans are for). And then wash your fine brushes with dish soap and warm water.
Oh, and I almost forgot, when doing kitchen floors add one more coat, the same would go for a heavily used dining room. And you will, in every case need to re-coat a kitchen floor every 2-4 years, and a normal used area, every 5-10 years. It just depends on how well you maintain the floor. In all cases if the floor looks good at the maximum times I just mentioned screen and re-coat it anyway. This is the only way to prevent water damage in the future. Well-coated sand on site floors will be more moisture stable, and will not form gaps in the dry winter months. All the methods I have mentioned so far are NOT for the pre finished floor. With all the little beveled edges, and the factory conversion finishes there is some doubt as to whether these floors will accept another coating of any type. There are new methods out there for recoating prefinished floors, but until I test then for adhesion, I will not write much about them.