Floor Urethanes - Tips and Application

Not all floor urethanes are created equal. You can choose between water based and oil based products. The water based urethanes are newer technology. Tests have shown that they are quite durable.

I happen to prefer the commercial grade oil based urethanes. These are the products that are used on gym floors and other locations where there is heavy foot traffic. You will rarely find these products at a home center or regular paint store. It is easy to find them. Just call several hardwood floor companies in your area. They know the distributors or they will sell these excellent products directly to you.

If you can't find these, go with a name brand urethane from a top paint store. Make sure on the label it states that it is indeed a floor urethane and not a wimpy furniture urethane -one not intended for floor use.

Before You Open the Can

When you buy paint the clerk or you often shake the can before you open it. This mixes up the pigments in the paint so that the final finish is uniform. Shaking cans of urethane or varnish is a big mistake. Don't do it! the shaking action injects lots of air bubbles into the urethane. These tiny bubbles don't always go away before you apply the finish or before it dries. Simply stir the urethane with a paint stick. The proper way is not to go round and round like you might stir coffee. You pull the stick from the side of the can towards the middle while lifting the stick up. The lifting action pulls up thicker components from the bottom of the can and brings them back into suspension. Do this for about one minute and you will be in great shape.

Applying Urethane

If you are urethaning a large area - anything over 100 square feet, then you should use a lambs wool applicator. This is what professional floor finishers use. This applicator is available at most paint stores and home centers. It attaches to a pole and you use it to spread the urethane evenly over the floor. The urethane is poured in a line on the floor. You then use the applicator like a bulldozer. You push the urethane in front of the applicator leaving a fine film in the wake of the applicator. Hold the applicator at an angle so the excess urethane is forced to exit the side you are working towards. If excess urethane escapes the other side, you will get a ridge line on the floor. Think how snow plows work.... This is exactly why they tilt the blades at an angle! Don't go back and forth! Use one straight forward motion from one end of the floor to the other.

You will still need to brush the edges. The lambs wool applicator is only intended to apply urethane to wide open spaces. You also need to work fast - especially if it is warm and there is significant air movement. Failure to keep a wet edge on the urethane will show up as streaks and lap marks. It is helpful to have someone do all of the brush work and applying urethane in front of the applicator while one person progresses across the floor non-stop with the applicator.

Be sure to lightly sand the urethane between successive coats. Vacuum up the dust before you do each coat. Before applying the urethane, wipe the floor down with a rag saturated in paint thinner or mineral spirits to remove every trace of dust. Burn the rag after you are finished.