Cabinet Scrapers: how to sharpen them

[Austin Dienner]

I have just recently bought a set of scrapers, and i am trying to find the best way to sharpen them. There are some articles on finewoodworking.com and the wood whisperer just posted a video on sharpening, But anybody that has anymore advice it would really be appreciated.

[Howard Acheson]

Here is the way I was taught years ago to sharpen a hand scraper.

The first step is to put the scraper in a vise and using a fine file, file the edge perfectly perpendicular to the sides. Only a couple of strokes should be necessary and this is normally only done on a brand new scraper or one in bad shape. Next, using a fine oil stone, hold the scraper flat on the stone and remove any burr and smooth the sides near the edge. Holding the scraper straight up on edge, hone the edge and then lightly remove the burr. There is a tendency for scrapers to dig into a soft waterstone so I use an inexpensive fine oil stone. 400 Wet & Dry sandpaper lubricated with light oil or WD40 would work fine.

Burnishing is the next step. After filing and being sure the edge is flat and 90 degrees to the sides, put the scraper flat down on, and slightly back from, the edge of your bench. Run your burnisher along the flat side of the scraper pressing at so the burnisher is tight at the edge. This starts causing the edge corner to extend. This is a step that burnisher jigs can not do. Now put the scraper in your vise extending up about an inch. With your burnisher, run it along the edge at 90 degrees from the sides. Take 2 or three not too heavy strokes. This causes the corner raised in the first step to be bent toward the sides of the scraper. Then tip your burnisher up slightly (10-15 degrees--really makes no difference) and take two continuous, firm strokes on each edge. That's it.

You will have to try scraping at various angles to find the "sweet spot." As the scraper becomes dull, go through the same three burnishing steps as above. You can burnish 10-20 times before stoning or filing is again required. It takes less time than changing sandpaper in a sander.

I greatly favor a real burnisher for two reasons. First, it is really hard metal. Second, it it highly polished. Both of these attributes mean that there is little chance of galling (or tearing metal from) the scraper edge. Galling makes for less than a smooth cut. The smoother the burnisher, the smoother the burr. Screwdriver shafts may or may not be hard enough and the chrome plating will eventually deteriorate. Drill bits are also variable in hardness. Using a valve stem from a car engine that has been highly polished is an alternative but, why not just get a burnisher?

Finally, you can control the aggressiveness of the scraper by the way you file/stone it and how you use the burnisher to make the burr. Stoneing with a fine stone after filing and then using ligher pressure on your burnisher will give you a less aggressive but finer cutting burr and a smoother finish. I have a thicker scraper that I sharpen to an agressive cutting burr that I use for initial work (ie: ripple removal after jointing/planing) and then a set of thinner scrapers that I put a finer edge on for finish smoothing and cutting down and smoothing varnish finishes.

Finally, to prevent frustration, scrapers work best on hard woods. Using them on pine is generally unsuccessful.

For an excellent description with pictures get Bob Flexner's "Understanding Wood Finishing."

[Marc Casebolt]

Austin,

There are a lot of instructions available, and most that I have seen will work well. Be sure to square the sides to the edge, then polish them well. Then use a light touch when turning the burr. It took me a long time to get the hang of it, but with a lot of practice you will find a method that works for you.
Don't expect to get it right the first time, or even the 10th time. Once you get the feel of it you will really love using a scraper. I have a sharp one handy at all times, and allways seem to find a new use for one.
Good luck,
Marc

[Austin Dienner]

thanks for the tips guys, they came in really handy

[Andrew Williams]

I do that whole process as well, but only after I re-burr the scraper many times with just the burnisher. I use the Tage Frid method (although He just uses the side of a chisel instead ofa burnisher). Just burnish the burr flat eith the face of the scraper, then re-burnish it on edge to your desired angle. This works a few times at least before having to file it again.

[James Owen]

I have just recently bought a set of scrapers, and i am trying to find the best way to sharpen them. There are some articles on finewoodworking.com and the wood whisperer just posted a video on sharpening, But anybody that has anymore advice it would really be appreciated.

Austin,

Here's a method very similar to what Howard poasted; you may find an additional thing or two of use:

A Technique for Preparing Card Scrapers for Use:

(This assumes that you are using a rectangular card scraper and are putting a burr on both sides of both long edges -- 4 burrs total. If you want to put a burr on all edges, then just repeat the appropriate steps as necessary for those additional edges. Card scrapers of other shapes follow the same general procedures.)

1) If this is a new scraper, you can probably skip this step. If not, use a file to remove all of the burrs already on the scraper: lay the scraper flat on your bench and file flat against the edges of the flat sides to remove the burr(s).

2) Put your scraper in a vice (if you're using a metal vice, you might want to protect the scraper with wooden or leather jaw protectors) with one of the user edges facing up.

3) File one of the long thin edges with a fine cut file, so that it is flat and smooth. Flip the scraper over and repeat for the other long edge.

4) Smooth both long thin edges on a sharpening stone (oil, water, diamond -- it doesn't make much difference; just be careful not to wear a groove into your stone; or you can use a "scary sharp" type system with sand paper and a flat surface). You want them smooth, polished, and square to the flat sides of the scraper.

5) Now smooth the "flats" of your scraper along the edges you just smoothed on your sharpening stone. Again, you're looking for a square, smooth, polished surface.

6) On a flat surface, use the burnisher to create an initial burr by pushing the burnisher toward the edge of the scraper, so that the burr sticks up past the edge parallel to the flat side of the scraper.

7) Put the scraper back in your vice, with one of the smoothed and polished "user" edges up. Now push a burnisher at about 15° off horizontal (the exact angle is not all that important, but a consistent angle is: a slightly different angle -- say 13° or 17° -- will work just about as well) along the entire edge to draw a burr on one side of the edge; you may have to draw the burnisher across the edge several times (3 to 6 times seem to be about average for my scrapers; you may need fewer or more strokes) to get an even burr. You want to push the burnisher across the edge with a moderately light but firm downward pressure. As far as possible (this may take a couple of times practice to get it down), you want the burr as even as possible and across the entire length of the edge.

A couple of notes on this process:

You can tell pretty accurately with your finger tips how even your burr is, but be careful not to slice them while testing it!!

Be careful not to slice your fingers while pushing the burnisher -- DAMHIKT.

Your burnisher can be a purpose-built one or a smooth hardened steel rod -- a smooth screwdriver shaft works perfectly well; smooth and harder than the scraper are what's important. IIRC, most scrapers are hardened to around Rc 48 - 52.

8) Repeat step #7 on the other 3 sides of the (long) edges. Your scraper is now ready to go.

Notes on Using a Card Scraper:

To use, hold in both hands and use your thumb(s) to press the centre of the scraper forward just a bit. Tilt the top of the scraper forward about 15° (this angle may vary) and push forward. You should get shavings; if not, adjust the angle forward or backward until you get nice fluffy shavings. As the burr dulls and wears away, you can extend its working life by increasing the forward angle of the scraper.

The easiest way to tell whether you have a good burr and are at the "right" scraping angle is that you will get shavings (just like from a hand plane, only finer and smaller). If you get dust, either your burr is not yet properly formed, your scraper angle needs to be higher or lower, or your burr is worn down and dull.

Scrapers can be pushed or pulled.

A scraper holder saves a lot of wear and tear on your hand and thumbs. Veritas makes a very nice scraper holder (it's a bit spendy); one can also be made in your shop from scrap wood and a thumb screw.

Scrapers get hot -- sometimes real hot -- during use.

While scraping, be careful not to scrape a dip into your surface.

Scrapers can be used to smooth the edges of boards as well as the faces. With a little bit of file work, you can also fabricate shop-made profiled scrapers that will smooth things like moldings, etc. (You can use old card scrapers, old saw blades, and mild sheet steel, for example, for making profiled and other scrapers.)

Hope that this helps you. If you have questions about specifics, feel free to ask. Scrapers are great tools that will give you a very, very nice surface quality, and will tame woods and grain that nothing else (except sand paper) will even touch. Every tool box should have at least one card scraper in it!

[Stephen Palmieri]

Here's a good tutorial http://www.liutaiomottola.com/Tools/Scraper.htm
It's the same steps as Howard described but with pictures.
I had never used a scraper before so I got the jig from Lee Valley and had very limited success so I figured scrapers weren't all they were cracked up to be. After getting one set up properly, I couldn't believe how well they work.

[Bob Smalser]

By golly, there's an illustrated tutorial right here:

http://www.sawmillcreek.org/showthre...=card+scrapers

The step the self-taught often miss is this one:

[Kevin Blunt]

Here is another tutorial from the wood whisperer.

http://thewoodwhisperer.com/?p=169

[Terry Beadle]

I recently bought the video Christopher Schwarz did at the Lie-Nielsen Toolworks. He discusses the different ways there are to preparing card scrapers ( he studied over a dozen of them ) and then he details and demonstrates a simple method that gets predictable results. I found the video to be a bit light but a whole lot better than it could have been. I guess I can say something and say nothing...hoot!

Anyway, his insight and demonstrations should put you on the path to enjoy one of the great secrets of the masters...card scrapers! Who needs sand paper?

I keep a half dozen of them ready to go. I use two methods. One is the quick fix and the other is the full monty..er? The quick fix is to take my 1000grit diamond stone with a suitable square bit of scrap and re-stone the two edges while holding the side of the card to the square side of the scrap. Then placing the card flat about 1 inch in from the edge of the workbench, I run my burnisher about 10 times to flatten the edge or concentrate the steel to the edge. Then I use the Veritas jig to set a 5 degree burr. Takes about 2 minutes.

Bye the way, as Mr. Schwarz points out in his video, you can use the David Charlesworth ruler trick on the card stoning with good results. I'm not sure it's needed as card scrapers are not RC62 like a japanease laminated blade will be. Still another bit of fun to try!

The full monty is to use a single cut mill file on the edges, followed by a complete stoning from 800 thru 12000 waterstones. Both the edges and the sides. The mill file has one of those square edge guides on it. Really gives you a square edge. Then using the burnisher and Veritas jig, as the quick method is described. This is particularly useful when working on blemishes in finshes. Works great on lacquer. The full stoning process is to give you the finest cutting burr. It's not needed for most scraping. Keep one card set with big burrs and another with really fine burrs. Mark them with a felt marker if need be but you should be able to tell a big burr from a fine one with just a little practice.

Card scrapers are like chisels and plane irons. Every one has his own little tweeks to it but they get the job done better than sand paper any day. IMO not said.

[Jim Shaver, Oakville Ont]

In the video/DVD Making a Shaker Table by Kelly Mehler, he shows how to set and sharpen a scraper. His method is the one I have used over the last 7 years, simple and easy to do quickly. Aside from that, for a beginning woodworker this is easily the best rough to finished project video I have ever seen....well worth the viewing.

[Robert Miller]

Once I finally got the hang of sharpening the card scraper, it brought a whole new way of thinking to my work. The scraper cuts the wood fibers instead of grinding them like sandpaper does. It's fast, it's quiet, it satisfying and it's cheap.
I use very little sandpaper now ,and the scraper leaves a fine,polished finish.
I liked it so much that I bought a old Stanley No. 80 cabinet scraper and that really converted me. You can sharpen it the same way as a card scraper, or put a bevel on the iron and then burr.
The shaving I can get from this thing are so fine that they are almost transparent. It's a learning curve to learn to sharpen these scrapers, but the rewards........

[Josiah Bartlett]

I was having trouble with the burnished edge of my scraper wearing out quickly until I polished the sides. Any surface roughness gets pushed out when burnished and makes a fragile burr.

I never thought about using car valve stems. I've got a whole bunch of bent BMW valves that I was going to make a wind chime out of, now I have a limitless supply of already hardened and polished burnishers.