Introduction: How to Sharpen Cabinet Scrapers

Cabinet scrapers are one of the most effective tools in your workshop and, when tuned properly, they are capable of producing a lustrous finish on most timbers. It is hard to imagine how such a simple and inexpensive tool can make such an impact on the quality of your woodworking.

A cabinet scraper is a piece of flat steel, that, when sharpened correctly, will produce fine shavings. The steel must be hard enough to hold an edge, but malleable enough to be able to create a hook or burr. A cabinet scraper may be used to smooth hard timber with difficult grain that is subject to tearout or fiddleback. It can remove machining marks or even out marks left by the sweep of a handplane.

Step 1: Preparing the Edge

This is a simple but effective way of achieving a good working edge on your scrapers. The edge must be straight, clean and at 90° to the flat sides of the scraper. Lock the scraper in a vice and, using a fine flat file, draw it across the edge, being careful not to create a hollow. If there is an old hook, file the sides flat as well as shown in the image.

Step 2: Remove the File Marks

Once filed, you need to remove the file marks with a medium to fine diamond or waterstone, (about 800 or 1000 grade). To avoid cutting grooves in the surface of your waterstone, use the narrow sides to hone your scraper. Be careful to maintain the 90° angle. Once you are happy that there is no hook left at all and the edges are clean and sharp, it’s time to create a new hook, see image.

Step 3: Making the Hook

Although at this stage the scraper is already sharp, you need a hook to achieve a fine shaving. This will act like a small plane blade.

To make the hook you will need a burnisher. There are a few products on the market—I use the Veritas Tri Burnisher or the Veritas Variable Burnisher. This is a much harder steel rod than the scraper, about 62-64 on the Rockwell scale. The surface is highly polished to ensure that the hook is smooth and free of tears that create scratches.

Hold the scraper in a vice and draw the burnisher across the edge of the scraper. You’ll need to make three or four passes, increasing the tilt of the burnisher each time. A tilt of about 10° is sufficient. Don’t use too much downward pressure when making these passes—you will only create a blunt scraper or too large a hook. Medium pressure is all that is required.

Step 4: Testing Your Scraper

If your scraper has been sharpened properly, it will produce fine shavings rather than dust. Bend it slightly and lean it forward so the edge of the hook makes contact with the timber. This angle should be no more than 45°—if you need to lean it more than this, the hook is is probably too acute, and has been applied with too much pressure. With the surface left smooth and the fibres sealed, scraping is a great intermediate step between planing and sanding.

The use of a cabinet scraper will significantly reduce the amount of sanding needed to complete a project, and give a much better foundation for your finish. For curly grain or fiddleback timber it will save you a lot of grief and time.

For more how to guides and reviews, visit www.woodreview.com.au or check out our Wood Review TV.

Comments

author
drichard58 (author)2016-04-27

One thing that I have seen that may help with this is to take a block of wood slightly larger (longer) than your card scraper (similar in shape to the one used to hold the scraper at a 90 degree angle to flatten the edge on the diamond waterstone) and cut a kerf through it on your table saw, not all the way so that you have two pieces, but far enough so that your scraper will fit in the kerf. This leaves a sort of "U" shaped piece that, if cut at an exact 90 degrees, you can use to hold your scraper when you flatten the edge and also to hold the scraper in the vice so you don't mar the face of the scraper.

author
CFLBob (author)2016-04-01

Would you clarify one little bit, please? When you say, "Hold the scraper in a vice and draw the burnisher across the edge of the scraper", I don't understand what you mean by that. Looking at your example photo, do you mean to hold the burnisher in that position and pull it toward you, or do you mean to to move the burnisher in some other direction? Perpendicular to the long edge?

author
Wood Review (author)CFLBob2016-04-10

Hi Bob,

Hold the burnisher at a similar angle across the edge to the one shown,
then draw it carefully along the edge, increasing the angle on
successive passes. If unsure find a teacher or someone who can
demonstrate in real life.

author
hesam khan made it! (author)2016-04-01

my name is barkatullah hesam

Image (3).jpg
author
DIY Hacks and How Tos (author)2016-03-31

Very well written tutorial. Also really good pictures.

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Bio: Australian Wood Review is Australia’s premier woodworking and woodcraft magazine. It is a high quality magazine for woodworkers that focuses on fine furniture making ... More »
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