Our natural oil finish in the process of going on the new red oak floor

Well dang, I’ve been waiting many days for this moment. Right now I’m happily sitting in a chair on our hardwood floor. That doesn’t sound particularly thrilling without any context though, I know. So… after days of grueling installation and sanding, we finally got to put the finishing touch on our new red oak floor — a special natural oil floor finish, one we’ve never before used. The application was a breeze / dream, your choice of cliche.

Really though, the finish went on extremely well. Best of all, of course, is that it’s a natural oil finish. This particular product is linseed oil-based (no polyurethane or VOCs here, thanks), it goes on in a single coat, and it gives the hardwood floor a beautiful “natural” tone and low gloss finish. The particular natural hardwood floor finish that I’m describing here is Rubio Monocoat, which I’ll talk more about below. So far, I really like it.

The Best Natural Hardwood Floor Finish…?

I spent a lot of time thinking about how we might go about finishing the hardwood floor we installed this autumn. I knew I wanted an oil finish, likely linseed oil-based, something I could put on without suiting up in a biohazard outfit and a breathing machine. Something that was zero VOC, easy to apply, and proven. Polyurethane was/is simply not an option for me. (I don’t even really like the way it looks, never mind the fact that it is petroleum-based, stinks for weeks, diminishes indoor air quality, and cannot be easily disposed of.)

At first I thought we might use a product from Heritage Natural Finishes, one of my favorite manufacturers of linseed oil wood finishes. However, they don’t have a specific hardwood floor product, and curing could take quite a long time. I couldn’t find any in-depth documentation from people who used Heritage on a floor, and I wasn’t feeling particularly adventurous, especially on our first “real” hardwood floor installation.

One can looks like this, with the “B” accelerator in the smaller can below… less than one of these did almost 800 sq. ft.!

Rubio Monocoat Review

And then I found Rubio Monocoat. Its advertised features include the following: it’s linseed oil-based, contains no VOCs, cures in a single week with the optional accelerator, it can be spot repaired very easily, and it goes on in a single coat. Now that’s quite an appealing list of features, eh? Well, so far most of it has proven to be true. Of course the floor is brand spanking new, so I can’t speak to the overall durability and longevity of the finish, but I did find a very promising review and product test from these informative folks suggesting very good durability and water resistance.

The Best VOCs are Zero VOCs

It’s nice to work with materials and not have to get all crazy with protective gear. It’s also nice to know the materials in your house are not contributing to poor indoor air quality or causing you unknown long-term health implications. The only questionable ingredient I could find in the whole Monocoat kit and kaboodle is Hexamethylene diisocyanate, which is a polymerizing agent (hardener). However, it’s only present in the “B accelerator” and less then 0.5% of the total. Yes, ideally 0.0% is best, and in that case you have to forego the accelerator and wait three weeks for the floor to properly cure. The choice is yours… (we went with the accelerator due to time constraints). Other than that, this is clean stuff, from what I can tell. By the way, here’s a good read on why zero VOCs is a wise choice.

Appearance and Color Options

An oil floor finish is very different in appearance (and performance) than a polyurethane finish. The “Pure” version of Monocoat, which includes no pigmentation, darkens the wood and gives it an amber hue. The finish is much more matte than glossy, which I particularly like. It really lets the natural grain and color of the wood shine through.

We tried these two samples, and almost went for the Charcoal (on the right) before deciding for the straight “Pure” without pigments

Interesting to note is that Rubio Monocat comes in a variety of colors. There are various pigment options, and we actually originally decided on the Charcoal, which would have turned the entire floor a blackened color. At the last minute, we scratched that plan and went for the default “Pure” finish. (Because we used no. 2 common red oak, there is lots of funky grain and natural defects in the wood… applying a darkening finish would have exaggerated all of those wild spots and been a bit chaotic. On a very even grained floor, I think the Charcoal could look really sweet.)

Applying Rubio Monocoat Floor Finish

Color me impressed. Applying Monocat was as easy as squirting tiny amounts of the oil out of a bottle, using a floor buffer to spread it and coat the floor surface, and then following it with a buffing pad to remove any excess. The first thing I was blown away by was how much coverage you get with such a tiny amount of oil. Because Monocoat doesn’t actually penetrate the wood (instead it has a molecular bond with the surface of the wood), it goes very far. In fact, we did all 800 or so square feet with less than one of their 1.3 liter cans.  The smell while it’s being applied and curing is actually quite sweet and almost floral, by the way.

This gives you a good idea of how little oil you need to apply at any one time

Note that you actually start at the edges and buff the perimeter by hand, and then move on to the rest of the floor area with a buffer. A buffer is optional, but it simplifies and speeds up the entire process significantly. Check out this video to see how Monocoat gets applied.

First you buff the edges by hand, and then move on to the main area with a power buffer

The cure time of the Rubio Monocoat Oil Plus 2C with the B accelerator is 7 days. Without B, it’s three weeks. I suspect the cure time is actually even a little less than 7 days, but just to be safe we were as patient as humanly possible and waited until we moved any furniture onto the floor. Thankfully, you can walk around lightly (wool socks recommended) while the floor is curing. (We actually did a bunch of painting while waiting the seven day period.)

A look at a section of floor before the Monocoat has been applied…

…and another look, with the Monocoat finish fully cured

In Conclusion…

I like Monocoat because of its beautiful simplicity. The fact that it goes on in a single coat, contains no VOCs, and has an amazing coverage rate are all very appealing. The appearance is quite beautiful, and likely similar to other linseed oil-based finishes.

Anyway, I’m excited to see how this stuff holds up over time. I’m a fan of the fact that you can spot repair any damage in the future. Natural oil finishes may require more periodic maintenance than polyurethane, but at least it’s possible to do without totally disrupting your living space and creating a big stink (literally). You can simply sand the designated spot, dab a bit of oil on, and the newly repaired spot will completely blend with the original finish. You definitely can’t say that about polyurethane.

Well, so far so good. I’ll report back sometime in the future after we have some time living on our newly finished floor. Until then, I’m going to enjoy sliding around a bit in my wool socks…