Scraping Your Wood Floor, an Alternative to Sanding

by Bill Tindall and Stephen Thomas

In modern times, prior to applying the finish, wood floors are made smooth by sanding. Before sanders were invented, wood floors were smoothed with a plane and a floor scraper. This Neanderthal approach to floor smoothing is still a practical approach to be considered.

So why might you want to scrape a floor instead of hiring someone to sand it, or sanding it yourself? One reason might be to save money. It will cost several hundred dollars to have a 300 sq. ft. floor finished by a flooring company. It will cost almost nothing to do it by hand, assuming you don't acquire tendonitis. Another reason would be to achieve a better finish than a sander might do. While it is possible to sand a floor flat with no glaring sanding defects, finding someone with the skill to do it is difficult. If the professionals often get digs, ripples and scratches it is likely the inexperienced homeowner will do no better with a rented sander. These digs, ripples and scratches become the first thing seen when entering the room.

It is impossible to irretrievably mess up a floor by scraping. Compared to sanding, scraping removes little wood, so, unlike sanding, there is no risk to trying it. Scraping will work for all domestic hardwoods used for flooring. We do not know how scraping will work for imported woods.

The equipment to do your own floor is minimal. You will need a 2" Red Devil scraper, a floor scraper (available from Lee Valley or flea markets), a hand plane and/or block plane, some new medium sized files and a scraper burnisher. Some extra blades for the floor scraper are a luxury you may want to have. Knee-pads and a kneeling mat are also useful.

Your success in completing the job will depend on your ability to quickly and successfully sharpen your scrapers. The Red Devil is easy. Just file it at the same angle as it had when it was new. A medium file should be used for this task, for example an 8, 10 or 12" mill bastard. File until a burr forms. If a burr has not formed, then all of the worn edge has not been removed. It will not cut well until all of the old edge is removed. This point can not be over emphasized. There are two goals to be achieved in sharpening the floor scraper: the scraper must cut rapidly and the edge must be durable. There are many ways to arrive at a properly sharpened floor scraper blade. The following directions are for a beginner who may not have ever used a cabinet or floor scraper. During the course of scraping you will have the opportunity to sharpen many times, approximately once per 10 square feet. Experiment to see where you might make the process faster.

Filing. Lay the non-beveled side of the blade flat on an India stone (or equivalent) with a bit of lubricant (for example WD40) and with a few strokes lap away the worn hook. This operation leaves a flat spot on the edge that enables one to better see and feel when all the dull edge is removed in the next step. You may skip this step as you gain experience. The scraper can make alarming digs with its corners. Use a file to round the scraper corners.

Next, file a 45 degree bevel on the scraper iron using a sharp 8" mill bastard file (see below for alternatives). (Some people prefer a more acute angle, 35 to 40 degrees.) The file strokes should be almost parallel to the scraper blade, rather than perpendicular to it. When you can feel a burr the length of the blade, the old edge is gone. Every tiny bit of old edge must be removed. Failure to remove all the old edge is the leading cause of poor scraper performance. Filing should be done well away from the floor. Filings tracked or dropped on an oak floor can stain it black.

An 8" mill bastard file leaves an acceptable edge for burnishing without further honing, but this small, fine file is slow. A 10 or 12" mill bastard can be used to remove material quicker, followed by light honing with a medium stone. An alternative to relatively slow filing is to use a belt sander. Rig some kind of jig to hold the blade at the proper angle and grind away with a 100 grit aluminum oxide belt.

Burnishing. Great care must be used in this step. A careless slip will result in a severe cut. Remove the burr from filing by polishing the scraper's flat side using the India stone. A tiny amount of oil aids the next steps. Holding the burnisher almost flat against the scraper, burnish the back side (non-beveled side) of the scraper using many strokes until a nice shine is seen at this surface. This step will form a sharp edge that can be felt on the bevel side. Hold the scraper vertical and with a burnisher at an angle of 15 degrees from horizontal (75 degrees between beveled side of the scraper and burnisher) form the hook with one moderate pressure stroke. If you are inexperienced with a burnisher, a Veritas burnishing tool set at 15 degrees can aid this step. Another convenient technique is to lay the scraper flat and overhanging an edge (a jointer bed, bench edge or a block of wood) with the bevel side up. Burnishing begins with a stroke or two against the beveled edge and then the burnisher is lowered and stroked again a time or two to establish the curled cutting edge. When done successfully, the curled edge stands up prominently from the scraper surface.

The second leading cause of scraper failure is rolling the edge over too much. This can be accomplished by using the wrong angle or too much pressure. If "the wave crests", so to speak, you can't lower the scraper handle enough to get a bite.

Attacking the floor. The objective is to remove any high spots on board edges and ends and to remove machining marks and the glazed machined surface. There is no need to make vast areas of the floor dead flat as they won't stay that way even if you were successful. To begin leveling the floor, decide on a strategy. For example, work on a strip 12" wide by the length of the flooring run. Inspect the target area. If a flooring board end or edge sticks up prominently, try mowing it off with a plane. Because you are not trying to achieve level across a large area, a short plane will prove most useful. Oak flooring has unpredictable grain changes and you may find a plane difficult to use in some areas. Attack these problem areas with the Red Devil scraper. This crude tool hogs off wood rapidly when it is sharp.

When all the obvious parts that stick up have been knocked down, change to the floor scraper. One hand grasps the handle while the other bears down on the blade. Angle it slightly to the run of the floor and pull in long strokes. Big curly shavings that look like planer shavings will roll off the floor when the scraper is sharp. When crumbly dust forms, it is time to sharpen. Work your way down the floor with overlapping strokes. All of the original surface of the lumber must be scraped. A low angle light will help you to see the old glazed surface and machining marks in contrast to the newly scraped surface.

It is common for the scraper to hit a hard place and chatter, leaving behind a series of ripples. Angle the scraper the opposite direction and scrape this area again. If you try to remove ripples using the same angle that caused them, they will just get worse, like bumps in a dirt road.

Scraping is a demanding physical activity that puts a lot of strain on forearms. If you are in very good shape, you might do 100 sq.ft. per day on an oak floor. A less demanding pace is half that amount.

Scraping will leave some minor imperfections, for example ripples, that are hard to detect until the finish goes on. For a perfect floor, light sanding will be necessary. However, finish can be applied to the scraped surface without further sanding. Some minor imperfections may show up, but they will be proof that you have a hand scraped floor. Someone 100 years from now may stand in awe upon making this discovery.

The last step before finishing is cleaning. Every surface of the room, including the ceiling, lights, moldings etc., must be made dust free to minimize dust that will wait to settle on the freshly applied finish. The floor is best cleaned by vacuuming along with dusting with compressed air if it is available.

If all goes well your floor will look like the hand scraped white oak plank floor below. This floor was not sanded after scraping. It is finished with 2 coats of thinned Parks Pro finisher Oil Modified Polyurethane (Home Depot) gloss, followed by a third un-thinned coat of 1:1 gloss/satin.