Card Scraper Technique??

[Scott Rollins]

I have several card scrapers Lie neilsen, Lee Valley, and Woodsmith. I find that all of these scrapers dull after about 9-12 BF of Red Oak. When I say dull the shaving is powdery rather than like that of a hand plane. When I first start with the sharp scraper it cuts great. Whispy shavings beautiful surface. Is this normal? Does a scraper normally dull this quickly? I follow the following proceedure when sharpening:
1: file off old bur
2: Using a jointed piece of wood I hold the scraper 90 degrees to 220 grit sandpaper bonded to glass, then 400, 600 through 2000.
3: between grits I lay the scraper on the sandpaper and remove all burrs from edge to make 90 deg edge.
3: using Veritas adjustable burnisher make 3-4 passes at 0 degrees
4: using same burnisher I set to 7-10 degrees and 3-4 passes with moderate pressure.
The scraper has a uniform burr along the edge. The burr is very small--it just catches the fingernail.

Any help would be great...I have many more shelves to scrape. I need to sharpen tomorrow.

[josh bjork]

Scott, I use steps one and two on a new scraper but I generally never touch one with a file again unless something really bad happens to it. You should be able to burnish a few times before going back to the sandpaper. I've had good luck burnishing the burr straight up then laying it down again. I'm sure I read that here somewhere. Even then maybe 400 and up unless the edge is really ruined somehow. The edge lasts longer if you don't let it get hot. If one side starts to get warm use the other while the first cools down.

[Alex Carrera]

I too usually run the burnisher to pull the burr straight up, then I run it at approximately 10-15 degrees. I can do this multiple times before refiling. I think that the burr I pull is larger than yours, and I can get some good use on wood like Purpleheart (that I love and use all of the time) before I have to resharpen. This did take a lot of trial and error, but I'm finally happy.

[David Weaver]

I agree with the other guys. The only scraper I've seen that's really hard is a sandvik, and it's not a good one to learn to roll a burr on.

I have the LN scrapers, and they dull about as fast as you say. I flatten the burr out and re-roll it several times before re-filing. If it bothers you a lot to have to stop to sharpen, you can roll a burr on both sides of the scraper, and even both sides on the top, so you could have four burrs (obviously keep your hands from sliding around across the burrs on the top if you put them there).

Though they get dull fast, I think the low 50s hardness scrapers are still the way to go because of how easy it is to roll a burr.

I think the sandviks are about rc60 or something - as hard as a lot of chisels. You could always get them and try them and see how you feel.

[Eddie Darby]

I find that I can just turn over the burr a few times before I have to go back to square one.

[Scott Rollins]

I have never tried re-rolling the burr. I will try that before a half hour of sharpening. I guess the technique would be to first straighten by laying the scraper on a flat surface and burnish the edge "pulling the burr" I think is what David Marks called it. Then lay it back down at about 10 degrees.

Is this possible for a cabinet scraper also? I don't have one, but will be buying one if this technique is possible.

[David Weaver]

Can you tell us which cabinet scraper you're looking to buy? Do you mean like a Stanley #80?

If that's the type you're looking at, then yes, you do the same thing, except the edge is usually jointed at 45 degrees instead of 80 degrees to the face.

It may be a little easier to roll the burr because you're dealing with a "triangle" of metal that comes out rather than a 90 degree edge. You have to be more precise in rolling the burr because it goes in the body of the scraper at one angle and your burr has to match it, so it takes a couple of tries to get it right sometimes. You still do the same steps - joint the edge, touch up the jointed edge (and the face) with a stone, pull the burr and then roll it over.

It can be unpleasant with a #80 if you can't quite get the burr right.

Your options in that case are to get a scraping plane that has a mechanisim with an adjustable angle (see Stanley 12, Stanley 112 and Stanley 212).

The number 80 is cheapest, though, and it's a nice thing to have once you master rolling the burr.

[Alex Carrera]

I've found that leaning the burnisher about 5 degrees into the flat side of my #80 blade works the best. I am much more agressive with the card scraper, but the more upright angle of the #80 and the 45 degree bevel seems to work best with a burr that is near perpendicular to the face of the blade. I love my #80, but it's another one of those that drove me mad for awhile before I figured it out. It's easy to get it so it either makes sawdust or digs into the board, but once correct it's a great tool. However, I haven't had the pleasure of using one of the more feature laden cabinet scrapers.

[Robert Rozaieski]

I sharpen my #80 with a straight edge, not a 45 degree bevel. It works just the same as with a 45 degree edge but is easier to hone and turn the burr. I don't know why it was originally ground with a 45 degree bevel but I have found the bevel unnecessary.

[Scott Rollins]

I was considering the veritas version of the #80, however the scraper plane may not be a bad idea. Sounds like everything I have learned about hand work-it take some experience to get it right. On-Off swithes don't come on everything. I really do enjoy scraping and planing though. I just don't have all the tools yet.

[Alex Carrera]

Interesting, I may try that out.

[harry strasil]

I always start with just a few degrees a couple of times working the burnisher at an angle across the edge, then increase the degrees another few and so on till I get a nice burr, I do both sides of square edge while I am doing it.

My burnisher is the shank end of a solid carbide junk burr driven into a wooden file handle. a drop of honing oil on the burnisher helps too.