Scraper help...

[Jonathon Spafford]

I am trying to sharpen my scraper, but I can't for the life of me get more than a wimpy little burr off of it that makes notin' but sawdust. It is driving me nuts. I only have an el cheapo sharpening stone from home depot that probably doesn't have that high of a grit (probably not more than 400 or so). To burnish the edge I am using one of those sticks from a set of kitchen knive (dunno what else to use). How do you all sharpen your scrapers?

[Mark Stutz]

Jonathan,
Unless that knife steel is old and worn out it may be the problem. I just recently figured this stuff out...it was all like "black magic" before! The edge must be square, and what I have read and seen posted, is that the edge needs to be honed. Try using the shank of a chisel. Iv'e seen others post about a used push rod. I think Bob Smalser has a great post with a drawing for his burnisher. Once you figure it out it seems so easy...keep trying.

Mark

[josh bjork]

Are you using a bit of a guide when you use the stone? just a block of wood to keep the scraper vertical helps a bunch.

[Ted Calver]

Jonathon,
I agree with Mark that the "stick" is not the way to go. If you do a search for cabinet scrqper you will find lots of threads with detailed sharpening instructions. I finally bought a burnishing tool, but before I did I had good luck with an old valve stem I had laying around. In a pinch, give a phillips screwdriver a try, or a hinge pin. The burnisher is not supposed to be an abrasive part of the sharpening process--it just draws the burr out.

[Joe Meazle]

I use the back of a 1/4" spindle gouge from my el cheapo HF turning set. One thing that heelped me was drawing the burr out more before I turned it. A little oil makes this easier too.
Joe

[Mark Singer]

Jonathon,
A common mistake at the beggining is to rool the burr over too far. If you do it is turned into itsellf and will not cut. First draw it flat and then put it in a vise and roll it just a little...less than 90 degrees. Try it. You can then roll it a bit more. Use a little oil to draw out the burr. If you are not getting shavings there is no burr in contact with the wood.

[James Owen]

I am trying to sharpen my scraper, but I can't for the life of me get more than a wimpy little burr off of it that makes notin' but sawdust. It is driving me nuts. I only have an el cheapo sharpening stone from home depot that probably doesn't have that high of a grit (probably not more than 400 or so). To burnish the edge I am using one of those sticks from a set of kitchen knive (dunno what else to use). How do you all sharpen your scrapers?

Try this (a compilation based on many people's suggestions and techniques here on the Creek; special thanks to Bob Smalser):

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!

[Derek Cohen]

Here is a pictorial tutorial I made a while back.

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=22508

Regards from Perth

Derek

[Don C Peterson]

Thanks to James and Derek for sharing.

[Jonathon Spafford]

Hey thanks for all the help!! James and Derek those are really nice tutorials! I think I got my scraper working... getting little curls off instead of sawdust! Never new it could work so well! Thanks again!!