Floor sheen from room-to-room looking quite different

Q: We are currently in our refinishing stage and having issues with the water-based polyurethane. We used a low sheen poly, but floor sheen from room-to-room is looking quite different. One is very shiny and another quite dull.

We can’t think of any variations in the previous steps, so we have no clue what is going on.

A: It could be a variation in the amount of flattener from one jug to the next, which is why it is often suggested to mix all gallons into one container and mix thoroughly. This isn’t always practical to do though. Make sure you mix the finish really well and pour it through a strainer into a pour container such as a plastic watering can. If you have stirred it well, the flattener should stay in suspension for 15 minutes anyway.

Similar Q: I used a semi gloss finish on my wood floors. The first room was perfect! The second room I used the same can of poly, however there was no shine, it was a dull finish. I assumed it was because I cleaned the brush with paint thinner. I applied a coat (from a new can) to the next room, and it was fine. For the final room I used the same can, the next day and used sponge brushes (not wanting to use the brush that I cleaned in the paint thinner) and once again the floors were dull. Do you have any explanation for this? I have used the foam brushes before with no problems. I’m very perplexed! Thank you.

A: Well this has nothing to do with the thinner used to clean your brush. Foam brushes have a tendency to create air bubbles and you don’t want those. The finish was not stirred or stirred enough, probably before the first coat to mix in all the paste sitting on the bottom of the can. A paste is added to change the finish shine from gloss to semi, satin, matte etc, depending on how much paste is added. Also, sometimes if the finish dries too quickly the paste in the finish, now applied to the floor doesn’t have time to settle to the bottom of the film, in which case it looks like gloss. The most obvious answer is not sufficient stirring. What you have on the first room is likely closer to gloss. On the rest of the work you got more paste interaction than what you hoped for. You need to get your stir stick all the way down to the bottom of the container to pull the paste off the bottom.

Follow-up Q: Thank you for that answer. I was wondering if that wasn’t the case after reading some of the other posts. I had also read somewhere that you shouldn’t shake the poly, but I had them shake the can of poly on their paint shaking machine at the store where I purchased it with no problems. Of course I don’t remember now if I used it right after that or the next day. Is it okay for me to shake the can prior to use?

Thank you again for the speedy reply.

A: I’m trying to answer promptly, knowing people like yourself are likely in the middle of something and are rather urgent. Shaking is not a good idea. A good thorough stirring is the way to go. I’ve been using Poloplaz Primero for years now. I still remember when I first started using it, I commented to the sales manager how the paste seemed to stay suspended in the finish, requiring very little stirring. He said they spent a bit extra to accomplish that because people often don’t stir the finish enough. Every other such finish I’ve used over the years, and I’ve used numerous brands, they all look like gloss until you get your stir stick down to the bottom of the container. Then you find the settled paste.

Ok, so now you know the deal, you should be okay. Don’t forget to thoroughly buff the existing finish with fine abrasive before applying another coat.