The term scraper brings to mind a tool for cleaning old paint from wood. That is certainly what you will get when asking for a scraper at the local hardware shop. It seems a poor term for a tool capable of the finest of cuts and with great accuracy. I would say it is an indispensable tool in any decent woodworking shop. I will also say that it is a forgotten tool in this era of power tools where everyone will have you believe that Ryobi is the answer to all you problems!

The term is something of a misnomer, for when properly sharpened, the scraper actually cuts rather than scrapes, much like a chisel or plane, slicing of paper thin shavings of wood. As useful as the scraper is, few people understand how to sharpen and use this very simple, much underrated tool.

Scrapers can come in various thicknesses and sizes but the sharpening method I will describe is the same for all. A standard scraper will be a rectangular piece of steel, about 60mm x 125mm and less than 1mm thick. For curved surfaces thin flexible steel that will conform to the curve is better. The gooseneck scraper has a variety of curves that can be used on tight curves or moldings. I keep a number of scrapers around for different purposes.

A rectangular scraper consists of four edges and two faces. The cutting is done by a small burr formed at the juncture of a face and an edge. Such a juncture is called an arris. The quality of this burr and the cut it makes is entirely dependent on the quality of the intersecting faces.

How to sharpen a scraper:

To sharpen the scraper, first dress the two long edges with a single cut mill file. Clamp the scraper vertically in a vise and draw the file length ways along the edge, trying to achieve a straight edge that is also square to the sides. The arrisses should feel sharp to the touch. If not, keep filing until they do.

Next polish or hone the faces on a flat oil stone. I use a medium India stone followed by a fine, hard finishing stone – a black Arkansas in my case. Water stones or Diamond stones (if you can afford them) will also do the trick. Be careful to keep the scraper flat on the stone or you’ll round the arris.
Then, polish the long edges of the scraper by holding it vertically between both hands and rubbing it to and fro on the stones. Hold it diagonally across your stone to prevent uneven wear! Again, the arrises should feel sharp to the touch.

A burnisher is required for the next step. It must be round, smooth and of a harder steel than the scraper. Many things will work well as a burnisher; the round shaft of a screwdriver, the back of an old gouge. I made a good one by fitting a turned wooden handle to a buffed up pushrod from an engine. Whatever you use, a little lubricant between scraper and burnisher helps a lot. A drop of oil is fine, or just rub the burnisher across your nose –it really does work!

Two steps are required to make the burr; raising the burr and turning it. To raise the burr, lay your scraper flat on the edge of a firm surface, hold the burnisher just a few degrees off horizontal and stroke it firmly back and forth along each arris. You should hear a loud tick as the burnisher goes off the end of the scraper with each stroke. What this does can be seen under magnification, an ear will protrude from each edge that has been burnished. The drawing shows an exaggerated cross section.

Next the burr need turning. There are different methods but this is how I do it. Clamp the scraper vertically in a vice, place the burnisher on the far end of the edge and firmly pull it toward you with downwards pressure. Two or three firm strokes should do, first at 90 degrees and then with the handle lowered slightly at around 85 degrees to the side of the scraper. It is important to hold the burnisher firmly and make long slicing strokes which extend over the whole blade. This will keep the edge smooth and prevent nicks or grooves. Taking several passes will turn a large burr which will take a large shaving. However, a large burr takes longer to turn and I’ve found them to be more brittle and they degrade rapidly. I prefer a small burr; it is less work in the long run.

Why scrape, rather than plane or sand?

Scrapers are commonly used to remove a fair amount of wood from a surface. A plane can easily tear interlocking or wavy grain but the scraper can manage nearly any awkward grain. They remove material quickly and leave a finished surface. No need to work your way through different grit sand papers!

Some notes on technique.
Flat surfaces.

To scrape a flat surface, hold the scraper nearly perpendicular and push or pull it to take wide shavings. To maintain the flatness of a large surface, like a tabletop, it is essential to cover as large an area as possible with one stroke of the scraper and to introduce as little curvature to the cutting edge as possible. A curved scraper will make a concave cut, the more you curve it, the more the concavity. Good for some applications but not for the tabletop! To avoid curvature, hold the scraper with your fingers behind the cutting edge and thumbs in front. Maintain a constant angle to the wood, as close to perpendicular as possible and draw the scraper towards you, attempting to produce a shaving almost the full width of the scraper. Proceed across the surface with a series of long and slightly overlapping strokes. I prefer to pull the scraper but you can push it too.

Unlike a plane, the scraper has no sole and may therefore ride up and down over hard and soft areas and create ridges on the surface. To avoid this, the scraper should be slightly diagonal to the direction of the wood grain. Alternate the diagonal direction every other stroke so that the edge will only take material from the high spots, leaving a flat surface.

For a fine, finishing cut, a small, sharp burr is needed. If the scraped surface isn’t good enough, re-stone the scraper and turn another burr. Obstinate grain may require that the angles diagonal to the grain be increased to produce a skewed cut.

Concave or convex surfaces.

Depending on the curves, use a flexible rectangular scraper or a gooseneck scraper. By springing the scraper between fingers and thumb, the cutting edge can be made to conform to a variety of curves. As the curve of the scraper tightens, the cutting angle is inevitably lowered. As the scraper is lowered, the burnishing angle of the burr must also become more astute to maintain the proper cutting angle of the burr to the wood. You may need to experiment with various angles at first, but you will get the feel of it with experience.

Resharpening.

As soon as the scraper no longer takes a shaving, it is time to resharpen. You want shavings, not dust! It is possible to re-turn a burr with the burnisher several times before having to go back to the file and stones. Burnish the face first, and then turn the burr. When the burr becomes ragged and leaves marks on the wood surface, it is time to go back to the beginning of the process.
Remember, putting of sharpening because of laziness, ultimately costs more time and energy!
As with all edge tools, the joy of using a sharp scraper is well worth the effort of taking the time to sharpen.

The million dollar question: Where do you get a scraper?

Your local hardware shop probably doesn’t even know what a cabinet scraper is. I doubt you could buy one in SA, maybe at Hardware Centre in Cape Town or Johburg.
Don’t despair, they are easy to make. First find an old handsaw. Any type or brand will do. I always see sorry examples of handsaws in pawn shops, about the only thing they are good for is to make scrapers with. Use one of those thin steel cutting discs on a baby grinder to cut a number of different sizes and shapes from the handsaw blade. After filing the edges straight and square, you are good to go! I have gathered a good collection of pretty decent scrapers this way.

HAPPY SCRAPING!