Thread: Sharpen Card Scraper

1. have you jointed the edge to 90 degrees using a mill file and then draw filed to get the edge smooth?
2. have you then polished the edge to around 1000 grit on a stone? -- my preference is an oil stone and I use a block of wood to keep the scraper at 90 degrees to the stone, and if you didn't draw file you will need to start with a coarser stone.
3. have you polished both faces of the scraper on the stone?
4. what sort of burnisher do you have? Polished carbide or are you using a screw driver?
5. at the bottom of this page Veritas® Tri-Burnisher - Lee Valley Tools (in the buy this tool line) is a link instr to a printable sheet describing how to use a burnisher

Originally Posted by ian

1. have you jointed the edge to 90 degrees using a mill file and then draw filed to get the edge smooth?
2. have you then polished the edge to around 1000 grit on a stone? -- my preference is an oil stone and I use a block of wood to keep the scraper at 90 degrees to the stone, and if you didn't draw file you will need to start with a coarser stone.
3. have you polished both faces of the scraper on the stone?
4. what sort of burnisher do you have? Polished carbide or are you using a screw driver?
5. at the bottom of this page Veritas® Tri-Burnisher - Lee Valley Tools (in the buy this tool line) is a link instr to a printable sheet describing how to use a burnisher

consider me astonished. The methodology I have been using (I think I gathered it from Fine Woodworking Mag - but maybe some other publication) is to use a coarse-ish stone at 90 degrees to get a burr on the edge of the scraper. Then lay the scraper flat on a hard surface, burnish along the flat side, then stand it up on the edge opposite the edge and burnish again, to create a cutting edge out of the burr made by the stone.
No polishing, no files ... no getting it super smooth in the first place. I expect your cabinet scraper shavings may look different from mine. But ... it works for me.

the hard things to get right are: find the right burnisher - I use the shaft of a certain very smooth and hard screwdriver. But not all screwdrivers are the same - only some tools work for me to get a good burr going. The other thing is the angle at which I hold the burnisher. Fairly flat works for me, I'd guess 90+20 degrees. But that is something that just came to me with practice. Many, many times I didn't get a cutting edge. If not, rinse and repeat or, in the end, go back to the stone and try for a better burr. These days it's muscle memory.

most times I can get an acceptable result by just re-rolling the edge.

jointing, polishing, etc is only really required very occasionally, but freshly sharpened I get shavings like those from a plane.

I make my scrapers from a piece of handsaw blade. A nail punch burnishes them just fine.

Yes to all. Carbide burnished. I just watched a guy use a file on the edge only and get beautiful shavings. I tried it. So far the same or minutely better then before.

Did you purchase your scraper blades, or amke them yourself? Checking here that the steel is not too hard.

One can create a working scraper by filing the edge alone. However, it is the resulting quality of the surface on the wood that determines whether this is good - not the shape of the shavings.

The following is a pictorial of what to do: http://www.inthewoodshop.com/Woodwor...29Scraper.html

Regards from Perth

Derek

Are you using a guide to ensure that your file or stone is at 90 degrees to the scraper? What wood are you testing on? Scrapers and soft woods aren't the best combination. Open grained woods will also tend to produce strange looking shavings but the surface of the wood should be smooth. Can you feel the hooked burr on the edge of the scraper? You probably won't be able to see it, but you should feel it.

Originally Posted by sussertown

I just watched a guy use a file on the edge only and get beautiful shavings. I tried it. So far the same or minutely better then before.

what you are describing is, IME, a consequence of a rough edge.
I suspect that the guy you "just watched" was draw filing and you are not.

I've just been through this and buying a german carbide steel polished burnisher was the key for me. Now I do one lap each side on a 600 diamond stone then two or three perpendicular then half a dozen laps with the burnisher on both faces flat then a few degrees of angle. Then I run the burnisher back and forth square and gradually roll the edge around to about ten degrees either side. That seems to be giving me a good edge on an olds scraper made from a piece of bandsaw. I also have a little set of very thin new scrapers and the method is not nearly as good but still good enough to get fine shavings. The plan now is to work up a few shaped scrapers from old handsaw blades. Good luck with it. It is very satisfying not going through sheet after sheet of sandpaper.

I've do e this.

Originally Posted by derekcohen

Did you purchase your scraper blades, or amke them yourself? Checking here that the steel is not too hard.

One can create a working scraper by filing the edge alone. However, it is the resulting quality of the surface on the wood that determines whether this is good - not the shape of the shavings.

The following is a pictorial of what to do: http://www.inthewoodshop.com/Woodwor...29Scraper.html

Regards from Perth

Derek

I've tried it on ash and grade a pine. I always have hooks

Originally Posted by Alkahestic

Are you using a guide to ensure that your file or stone is at 90 degrees to the scraper? What wood are you testing on? Scrapers and soft woods aren't the best combination. Open grained woods will also tend to produce strange looking shavings but the surface of the wood should be smooth. Can you feel the hooked burr on the edge of the scraper? You probably won't be able to see it, but you should feel it.

If all else fails, go to a local woodworking club (or woodworking business for that matter) and ask someone to show you how to get it right. Well worth the effort.

Brian

I got myself a Veritas burnishing tool. It's only very short and not too expensive and it's well worth it. I also make sure I get rid of all the hooks every time I hone the edge. Also I find that if you are having trouble getting hooks on your burnishing. Set a slight bevel angle on your scraper say 75°. I grind my scraper plane blade at 45° because it much thicker and is quite hard to form hooks if the edge is a straight 90°

If your using the file and getting the scraper all true and square . Then getting it all fine and square on the stone . And you have a carbide burnisher. The problem I think is the pressure you may be applying .

If there is no sharp hook to shave then give it another go with more pressure .
I watched a youtube guy give a demo and he had shavings coming off the wood at the end but I doubt it would have been for long .

I use a lot more pressure than he did forming the final hook . I hold the scraper and slide it over the burnisher leaning quite a bit of my body weight down onto it with the scraper leaning over between 5 and 10 degrees and give it three good hard swipes so it clicks hard into the bench as it slides of the burnisher.

Your trying to reform a tool steel with a harder tool steel, its tough stuff!!
HSS drill bits wont drill saw plate its so tough . Go hard at it when your trying to form the hook!
Not as hard as you possibly can but a good 70 %.

Rob