Smoothing Out Mesquite Floor Using Tongue Oil


I’m in the process of laying a mesquite floor in the first of 2 bedrooms. I’ve ripped out the 30 year old carpet and pad and am gluing (PL-400 construction adhesive) 3/8 inch thick tongue and groove strips of mesquite to the subfloor. The installation is going well, if slowly – it’s one of those spare time undertakings. What I’m noticing is that the floor isn’t going in perfectly smooth. Especially the butt joints at the ends of some sections are less than perfect mates. So I assume that some sanding will be necessary. I had thought to rent a random orbital floor sander, but your article makes me question it’s practicality.

So (if I can locate one locally) I guess I’ll need to hire a professional to accomplish the sanding. I’d appreciate your thoughts on that. Second concern – there are some open spaces due to warped boards and other issues. I’ve seen a mesquite floor where the holes, etc., were filled with a black material and I really liked the end result. Any suggestions? Is this an epoxy? (My friends bought the house and don’t know who did the floors.) Then we come to finish. I’ve had several different finishes recommended to me and I guess I’d like to hear your thoughts. I do not want a high gloss finish! But I do want smooth. Tongue oil has been suggested, especially one with a polymer “filler”. Do you wax over tongue oil? Maintenance is a concern (a minor one, but a concern none the less.)

Thanks for your time. I’m looking forward to hearing from you. Les


Dear Les

While I don’t agree with the method you are using, as longs as the glue is a urethane adhesive, and cures properly you will get the wood at least initially, to stick. The problems occur when there are changes in indoor humidity. Get a Wet-Dry bulb hydrometer to check this. When and if the indoor relative humidity changes by 20-30% the wood will shift and break off the glue. Don’t let this happen!!!! I can only recommend the Dri Tac 7500 urethane adhesive ( for this least favored method of solid wood installation.

The wear layer on this very thin floor is only 1/8″ and you should HIRE a pro for this rather tricky sanding job. But do the finishing yourself, that’s the fun part anyway. You really should use a good oil modified polyurethane.

Fill the floor with colored latex filler before you sand. Choose whatever color you want, you can mix in a black paint tint to the filler if you wish. I would prefer one that is the same tone as the finished wood.

You need to have a moisture resistant finish, on this poorly fastened wood. You need to keep the moisture content of the wood stable and the oil finishes you have been told about have little ability to do this. You may use a satin finish OMP, which will look like a waxed floor.

Wax in itself is not a finish, just a top dressing for a film finish like OMP or varnish.

One doesn’t wax over an oil finish in any case, as this type of finish cures softly, and the solvents of the wax will remove it. You could wax over a polymerized oil finish (which is called a oil/varnish) but it would have to cure for a month, before you do so. And most polymerized oil finishes are just weak forms of varnish anyway, so you will no avoid the toxic fumes, and metallic driers, by using these.

There is one exception to this and that is the Tried and True oil/ varnish, at But you may have to apply 6-7 coats of this finish to achieve a water repellant and durable floor finish. These are really furniture finishes, and will only stand up to gentle use on floors.

All in all the mesquite is a nicely textured ring porous wood, very durable, with good moisture stability.

Now read my floor maintenance article, which can be found in the search box at the top of this web page.