Should I wax or polyurethane an old pine floor?

Question

I found another question that sort of asks this, but the answers don't provide any detail.

We bought a 1918 house in somewhat rough shape. The second floor (with two bedrooms and a nursery when we're done with it) has (we're told original) pine floors that were treated years ago with some kind of polyurethane. Much of it is peeling (or has peeled) leaving exposed wood.

Treatment options I'm considering are polyurethane and Rubio Monocoat, which is a wax finish. The Rubio product claims 0% VOC, and comes with a number of stain colours. Multiple people we've talked to say that wax is the "better" choice for a century old pine floor, but can provide no concrete reasons as to why.

So my question is ... Why?

Is the amount of work and extra expense for a wax finish really worth it? What does a wax finish get me that I'd lose out on with polyurethane?

And finally... Has anyone got an opinion of Rubio Monocoat? Aside from the colour options, is it really that much better than basic tung or linseed oil?

I realize that if I sand things down and apply poly, there's no going back. I just don't think I know enough to make the right decision.

Answer 1

You already answered why; the poly that was put down is peeling off! My parents tried to use poly on a new pine floor when I was a child. It peeled and chipped and wore off in areas after about 2 years. I suspect (now) that the difference in rigidity was the primary reason for the separation of varnish (hard) and pine (soft). Surface finishes like varnish dry on top of the wood. I'm afraid I don't know why varnish would be worse on an old pine floor. Actually I would be inclined to believe the opposite because old pine should be harder; but it's really just a question of which is worse new or old pine?

I believe that Rubio Monocoat is probably derived from tung or linseed oil; it contains a drying accelerator (aka siccative); perhaps they use a manganese salt like manganese acetate. I'm not familiar with Rubio Monocoat so I can't say anything about their quality (sounds interesting... might work). There are many possibilities for what this material could be, but it's not wax.

Modern floor waxes are actually not true wax either; they are (typically) acrylic polymers. But that doesn't really matter, the point is that floor wax does work on pine, or at least it won't peel off.

Answer 2

When you say is there really any better than tung or linseed oil it will certainly be easier to apply. Especially with respect to tung oil which is supposed to have at least 5 coats and should be dried and sanded between each coat.

I think it's the ease of application that your really paying for with these synthetic finishes.