What do you think of the water based polyurethane finishes? Are they too hard for Hickory plank floors? I am installing a Hickory floor in Colorado. I know that if I use an oil based poly it will yellow, but have been told that even though the water based won’t yellow, it will be so hard that with the changes in temp. in Colorado, it will crack. Note: it will also be installed over radiant, in-floor heat!
What do you think is best?
I’m not sure if the issue of water-based finishes is their hardness, but their whiteness. The water-based industry goes to great lengths to point out that the oil-based poly turns yellow. Well the water based finishes whiten in time, and this may lead further down the line to the cracking you speak of. I have heard from art restorers that water based varnishes have not yet come of age, because the dried film still has the emulsifiers in it. These are a detergent like chemicals that allow the mixing of the oil and water in these finishes. They are large molecules and in time may migrate together as the finish continues to cross-link.
That may happen in as little as 5 years and the floor finish will turn so opaque that the wood grain will be obscured. And I suspect that in time also, with some UV deterioration in strong sunlight window exposure, this process will be speeded up. And then the cracking begins.
Although to be fair to the industry, they are trying to make safer finishes, and the Dura Seal company has come out with the third generation of water based finishes. (The first generation is still sold in stores now as a cheap acrylic finish, the second is the catalyzed industrial coatings used on gyms and bowling alleys). Read all about this in the article about the Dura Seal 1000 water based finish. It shows some promise.
For now I still use nothing but 3 coats of ply. If you want an article that will walk you through the use of Oil Modified Polyurethane, we do have an article on this. Use the search box at the top of the web page and type in ‘Oil Modified Polyurethane’ to find the article on this topic. It’s very detailed, and will teach you how best to apply the poly without bubbles and pits that most people experience when using this material. Well worth it.