Not a fan of polyurethane? Consider Waterlox, a tung-oil based finish.

Modern polyurethanes are great: they are easy to apply, easy to maintain, they hold up well, and the waterborne version has minimal solvent fumes.

For the first-time do-it-yourselfer, polyurethane is usually our first recommendation—although it does have some drawbacks.

Polyurethane works by building up multiple layers of plastic over your wood floor. These layers form a very effective solvent barrier, and they take the brunt of the day-to-day wear on your floor, since the wood is essentially encased in a clear plastic shell.

Unfortunately, that plastic shell obscures the texture of the wood grain itself and sets up the unreasonable expectation that hardwood floors should always look as smooth as a lake on a windless morning. But they shouldn’t.

There is another option.

A compromise that allows you to protect your floors while still appreciating the texture of the wood itself: a tung-oil blend called Waterlox.

Even though the name contains the word “water,” this is not a water-based product; it is a penetrating resin-oil finish. Its main component is tung oil, an aromatic, natural drying oil obtained from the nut of the tung tree.

Tung oil has been used as a wood sealer for centuries in China precisely because wood absorbs it so readily and because it does eventually “cure,” meaning that it hardens when exposed to oxygen.

Essentially, tung oil works by seeping into the wood and hardening, which, on a floor, allows the wood grain itself to take the wear of foot traffic. However, straight tung oil is neither as hard nor as solvent-resistant as polyurethane.

In Understanding Wood Finishing, Bob Flexner states that, “Tung oil can be made fairly water-resistant after five or six coats. But it is too soft and thin to resist scratching or water-vapor exchange and it is difficult to make the finish look nice. In addition, tung oil cures very slowly, and it turns white if left to cure in any thickness…so you need to wait several days between coats.”

Waterlox solves some of the problems associated with pure tung oil by adding resins that cross-link andwaterlox harden, forming a better barrier against the cola that will eventually be spilled on your floor. Yet the added resin is not so much that it builds up excessively over the wood grain itself.

Due to shipping restrictions, we can only sell Waterlox from our storefront or ship within the state of Minnesota.

Pete’s sells the Waterlox Original Sealer, Original Satin Finish and the Waterlox Marine Finish in gallons and quarts. If you live in our fine state, but can’t get to the shop in St. Paul, MN, give us a call and we can help: 651-698-5888.

Drawbacks to Waterlox.

The main drawback to Waterlox is that it is solvent-based, meaning that your home will smell of evaporating paint thinner during the entire coating process, which can take three to four days (dry time is 6 to 24 hours between coats, depending on temperature and humidity).

In addition, sometimes the Waterlox Original Sealer appears to be startlingly glossy, even though it is advertised as a medium sheen.

But its advantages outweigh these minor problems. Waterlox bonds well to itself, so you are not required to abrade the floor between coats unless you are experiencing roughness or grain whiskering.

Another Waterlox feature is that it can be tinted with up to one quart of old-fashioned, solvent-based stain (without additives such as urethane,or solvents like alcohol) per gallon.

Customers who are trying to recreate the color of aged shellac on maple, a species that does not take stain well, have had success using this method.

Be careful though; Waterlox has stopped recommending this practice on their website because many modern stains have been doctored to be faster-drying and the solvents that are added make those stains incompatible with Waterlox.

The sheen problem is easily solved by simply waiting for six months. Foot traffic will eventually soften the high gloss of the original sealer to a soft satin. If you can’t wait, you can buy a separate Waterlox Original Satin finish that will give you the lower sheen without the wait.

The only outdoor finish we recommend!

Waterlox also comes in a very high solid-content formulation that is sold as Waterlox Original Marine finish. It is more expensive than their Original Seal product, but it is designed to resist UV rays, freshwater, and saltwater.

Modern polyurethanes that are formulated for exterior use (porches, outdoor steps, or thresholds) can be disappointing because they break down and peel, usually after one winter’s worth of exposure, especially here in Minnesota where snow can sit on your steps for four months.

Because it is a penetrating finish and can’t “peel,” Waterlox performs better on exterior applications, though we do rub on an extra layer every fall just to be safe.

Even if you don’t have exterior hardwood that needs a natural coat, the Marine finish is still worth considering—especially for a kitchen or bathroom, or any room that has any road-salt-dragging winter boot traffic.