Modern chemistry has done us all a favor by bringing back these traditional, hand-rubbed oil finishes in a format that requires far less maintenance. Hard-wax oils are a hybrid of oil and wax, with a chemical catalyst that triggers a hardening action. The result is a durable, low-maintenance protective finish with all the aesthetic qualities of linseed or tung oil.
Rather than building a film of resins or plastics on top of the wood surface like a polyurethane, hard-wax oils work by saturating and bonding to wood cells, then hardening. Excess oil is wiped off, resulting in a lustrous, velvet-like texture that sits level with the floor surface rather than on top.
In addition to the aesthetic benefits, hard-wax oils offer three major benefits:
- Non-toxic. Most finishes contain strong chemicals known as volatile organic compounds, or VOCs. A typical oil-modified polyurethane will have 400 to 500 grams of VOCs per liter. A next-generation waterborne polyurethane will come in at a mild 150 g/l. But due to their alternative chemistry, hard-wax oils come in at an unbelievable 5 grams or less.
- Fast-curing. Whereas oil polyurethanes can take up to 14 days to fully cure, and waterborne versions take 5-7 days, hard-wax oils are ready to walk on in 8-12 hours, and have achieved their maximum hardness in about 24 hours, depending on the color used.
Permanent. Traditional polyurethanes will fade and turn yellow over time. Hard-wax oil, by contrast, will only deepen and intensify with age. As long as it is periodically refreshed with maintenance coats, there is a real possibility you will never have to pay for a full refinish.
All that being said, are there any downsides? Just a couple:
- Wear. While quite durable, hard-wax oils do not approach the abrasion-resistance capabilities of a high end waterborne finish. If you anticipate having a lot of grit tracked onto your floors, or if you have large dogs with untrimmed nails, hard-wax oil may not be the best choice for your home.
Sheen level. This isn't really a downside, but just something to be aware of. Because it is a penetrating finish, hard-wax oil has a very matte luster. Most homeowners who choose hard-wax oil do so for this reason, but if you are looking for a glossy, mirror-like finish, you're better off with a polyurethane.
Expense. Both the product itself, and the labor-intensive application, result in a 25-50% increase in cost.
Premium Installation and Refinishing
10" wide heart pine floors in the 18th century Francis Nixon House outside of Hertford, NC. Showcasing Poloplaz OMU.
On the downside: they are double to triple the cost of OMU finishes. Additionally, the water contained in these finishes can expose minor flaws in the wood that lead to additional repairs at an awkward stage in the process. Certain types of wood are not good candidates for a waterborne finish.
Antique oak boards finished with "Magic Oil," a leading hard-wax oil product
Waterborne polyurethane in a satin sheen
Hard-wax oils are a next-generation take on an old-fashioned recipe. In decades past, natural, penetrating finishes such as linseed oil and tung oil were used to give color, luster, and sheen to hardwood floors.
But because they held up poorly to foot traffic, they required a protective coating of wax that needed frequent maintenance and polishing. With the advent of polyurethanes, these finishes were no longer viable.
Finish Systems
Finishing is the final step of a flooring project, and perhaps the most critical. Finish both protects your freshly sanded floors and enhances the aesthetic qualities of the wood.
What makes a good quality finish? We've put in considerable time and experimentation to identify products that would meet three criteria:
- have an attractive, non-plastic surface that enhances the natural beauty of the wood
- offer long-term, heavy-duty protection against traffic wear and scratching
- have a non-offensive odor and low toxicity
Oil-modified urethanes
Oil-modified urethanes (OMUs) have been the industry standard for at least fifty years, and not without reason. They're inexpensive, easy to use, long-wearing, and attractive.
On the downside, it stinks! If you're sensitive to strong smells, you'll want to make plans to be elsewhere while your floors are being coated.
Drying time: it can take up to 14 days to
reach its final hardened and cured state.
You should make plans to stay off your
floors for 24 hours after the final coat,
and if possible avoid moving furniture
back in for 48 hours. Rugs should not be
placed for two weeks to allow for curing.
Our preferred brand is Poloplaz, among
the hardest finish available in any
category, and extraordinarily attractive.
Waterborne polyurethanes
The selling points of a waterborne polyurethane include light smell, quick drying and curing, and high wear resistance. It's great for scenarios with high traffic, where a quick turnaround is desired, or for anyone sensitive to strong solvents.
Lastly, as they age, waterborne polyurethanes
can end up with a hazy, plastic appearance.
Despite these drawbacks, there is a definite place for waterborne polyurethanes, and products continue to develop and improve as time passes.