Wood floors whether old or new add beauty and value to any home. When it comes time to restore them, the most critical aspect of the job is the sanding. Without hands on experience, a novice can make a serious mistake that can permanently damage the beauty and integrity of the floor.
As most wood floors are only 3/4" thick, they can easily be made thin by repeated or improperly done sanding. One way to know is by removing an old floor register and checking the thickness of the wood. At least you will know what you are dealing with
Rent your drum sander from a reputable place that takes time to show you how to operate it. Be sure to get the manufacturer’s instruction manual as well. The drum sander weighs about 100 lbs. but is relatively easy to maneuver. The danger here is gouging the floor beyond repair. Practice on an old piece of plywood first, if you can, to get the feel for the machine and its maneuverability.
You will need to purchase at least 10 sheets of sandpaper per room in about three different grits. Coarse grits, like 20, are good for removing shellac or paint. Medium grits like 80 are used for the second sanding. The final sanding is done with a 100 grit paper. You may have to pass over the floor two to four times with each grit depending on the buildup of wax and old finish.
Sand rough areas or raised ridges on a diagonal until they are smooth and then return to sanding with the grain. Sand two-thirds of the floor in one direction and one-third in the opposite direction, overlapping so you don’t miss any spots. Use an edge sander after each pass, to sand where the floor meets the walls and any other area you cannot reach with the drum sander.
Between each pass with the drum sander, vacuum the sawdust with a good shop vacuum. Be sure to wear ear plugs and a breathing mask while working. Once all the passes over the floor have been completed, you can fill any cracks or gouges and let them dry thoroughly before sanding smooth. Countersink any nails that have surfaced during the sanding process.
You can wipe the floor down with mineral spirits to remove the last residual bits of dirt and sawdust. Your floor is now ready for the next step which may be staining, varnishing or sealing. With the proper care during the sanding phase, your wood floors will remain beautiful and in good condition for years to come.
Written by Ronni Rebsdorf from Gulvafslibning.info – A Danish floor sanding company.