Solid Hardwood, Engineered and Laminate Flooring - Polyurethane.....Bubbles & More Bubbles

Im refinishing a hardwood floor, and need some help with how to apply polyurethane finishing, without getting bubbles. I've sanded this floor 6 times, and recoated with minwax polyurethane, and get millions of tiny bubbles, every time. I've adjusted the temp in the house, and applied while 65 degrees, and applied while 80 degrees. I've used everything that is recommended for application. sponges, poly rollers, lambscloth, and nothing but bubbles. I've used drum sanders, oscillators, belts, hand sanders.

Ive already lost my ass as far as money is concerned. I just need to get it done, so I don't end up in court. Any help would be appreciated.

I don't usually make a habit of bashing products (especially since that is frowned on here) but I dont care for Minwax's polyurethane at all. I would recommend you try another brand.

Could you recommend another brand?

In addition, don't shake polyurethane. Like James Bond, stirred gently. Like XSleeper, not that Minwax is a bad product, but there are better floor grade polyurethanes out there. I had a heart pine floor in a log cabin done with the same product used on basketball courts. Would not scratch and gave a good sheen.

Can you give a few names of better poly for floors?

Sherwin Williams has one called Dura Seal. You would want to be sure you have sanded off all the irregularities from the previous coats with 120 grit. And clean the floor with a tack cloth and mineral spirits before applying. Thin coats are best... thicker coats might result in more bubbles because the surface might tack up, and gasses can't escape. Spread the stuff as thin as you possibly can. I have never had good luck applying thick coats of poly. This might be your whole problem, not sure.

Good point by Chandler about not shaking... stir up the can completely with a stir stick- all the goody is at the bottom.

had some bubble issues when I did my floor about 17 years ago with the minwax floor poly...I use Varthane Diamond now...seems to go down smoother...and thin to win

whats the ratio of mineral spirits to a gallon of poly, without having to coat 5 times? What good for 2 coats, with a nice clear finish?

The thin to win is ....applied thin....not thined with thinner. I use a quality natural bristle 3" brursh (be carefull of first brush use as it might shed a bristle or two) I have found that lots of angled light will let you "see" how the finish is going down. the first coat is a no brainer but the second and third ( i normally apply 3) coat is hard to see your "wet edge" in dim or direct overhead light.

oh, ok. most people over at the rigid forums thin with mineral spirits, before they apply. are you using a good brush? (purdy, etc.)