I recently sanded and refinished my red oak floors. I used a water based polyurethane and everything turned out great. I noticed a couple of places that I missed with polyurethane so I brushed on poly in these places. As it dried it looks kind of honeycombed or like little puddles. I did use a different brand of polyurethane. What did I do wrong and how can I fix this?

Thank you very much for any input!

Hi there,
it looks like you used water-based poly to do the job and than you did touch-up with a different brand poly like you said. Was the different brand water-base also as well, or it was oil-based?

First of all, when it is about finishes (poly, polyurethane) the brand is not important, but the chemical composition is important. There are 3 main types of finishes that are used in the flooring industry with different chemical compositions: water-based, oil-based and catalyzed finishes. Lets call them 3 main finish-families. So the members of the same family work well together (touch-ups, re-coating), but do not work well or do not work at all with members from the other family. SO, THAT MIGHT BE A PROBLEM IN YOUR CASE.

Second scenario of what cased your issue could be that you didn't sand off the old previous finish, and in those places the new water-based finish that you applied, did not adhere to the surface of the floor, so it looked like you missed those spots during the finishing process. In this case, no matter what you would apply on top of those "missed" spots nothing is going to work.

Now, what to do. To fix the problem, I would hand-sand those problematic spots with 60-80 grid sand paper to the bare wood. If it is hard to sand, you can use scraper, so scrape the existing finish out of wood and then hand-sand to make the sides of those spots smooth. Than do more hand-sanding with finer grid sand paper (if you used 100 for final-cut than use 100, if 120 than 120 e t.c.). Now you have to apply on those spots with a brash exactly the same finish as you applied over the entire floor in the same amount of coats. For example, if you applied on the floor one coat of sealer and 2 coats of finish, than do the same for on those spots. It is very important to watch the edges of your application, it should be as smooth as possible, you don't want to make those spots very obvious like paddles. And finally, after you did apply the same amount of coats over the problematic spots, you have to screen-buff the rest of your entire floor with fine screen or sand paper (180-220 grid), do hand sanding of the fixed spots to maintain smooth edges with the same fine grid screen or paper, and than you'll have to vacuum, tack and finish the entire floor to make it all look the same WITH THE SAME EXACTLY FINISH that you applied before. This is the cheapest and the best way to do in your case.
The problem should be solved.

Best Regards,
The Flooring Ninja (Chicagoland, IL)