How do you guys sharpen and burnish a card scraper. Do you go all the way back to filing and hone from progressively finer stones every time you need to sharpen it or do you just start with the finer stone and burnish a new burr? How often do you go all the way back to the file?
ZABO
Replies
How often do you go all the way back to the file?
Always.. I am !NOT! saying that you should also or is the best method.
I rarely use hand planes. However, my (many) card scrapers, ALL the time.
I mostly use very hard woods for my project and using a scraper on them generates ALOT of heat which in my opinion 'hardens' the egde which makes it hard (no pun) to hone.
Back to a QUALITY file and a good grade oil. (Yes, I NEVER drag the steel back across the file teeth).
AND... I only use a burnisher to draw an edge down for very difficult grain.
I usually leave it flat! By the way, I have a little MDF jig I use to keep the scraper 90 degrees to the file. If I want a different 'edge angle', I have another jig made to that angle. I rarely use it.
YES, I get 'dust or tiny shavings' and not actual shavings you will get from a plane.
For the woods I use, I feel it is a waste of time going through all the fancy steps.
Purpleheart, Jatoba, Hickory, and some Ash will knock that wonderful curled edge off in one pass of the scraper!
OK, so I have also been known to use 'Box Cutter Blades' as scrapers...
Now listen to the other for good advice!
I file ,hone with a diamond stone ( best guess is 600 to 1000 grit) and then turn the burr. Usually only turn the burr about three or four times before going back to file etc.
Depends on the wood and how well I sharpened the scraper the first time.I have one scraper that is 3"x4" so I sharpen all four sides. The rest are sharpened on the long sides only.I have both the round and oval burnishers, for whatever reason I prefer the round burnisher.
mike
Zabo,
If I may add to the enlightened direction of Herr George in the previous post (;>), you might search the archives for other threads on the subject. In addition, Popular WW recently had a very good piece on their website.
Best!
-nazard
If I may add to the enlightened direction of Herr George in the previous post DAMN!
I'm of old German Kin.. We all fought on the USA side! Lost my Father and two Uncles doing it. Or were we called Penn Dutch?
Lancaster County, the scenic Pennsylvania Dutch Country. Here you'll discover Amish. We were NOT... My kin were just Coal Miners!
Kind of relavent to this discussion, something I gleaned from Woodenboat magazine: Broken glass works great as a scraper. Whenever it gets dull, just re-fracture it or break of a new piece. Just watch you don't cut yourself!
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
I only draw file the edge, burnish it flat and turn the curl, no stones. I can usually flatten and turn up the burr three or four times before hitting it with the file. I'm aggressive when flattening, buffing back and forth with the burnisher like a butchers steel. You can see the edge smooth out and polish. You can feel the edge is very sharp. I turn the burr with a few light strokes, I'm guessing between 5° and 10°. I do all four edges. If one isn't quite right, I lay it flat and turn it up again. I used to use stones and more time consuming methods but the results were not as consistent or as sharp.
Beat it to fit / Paint it to match
I do it similarly to what Hammer1 describes. I use only file and burnisher. I turn my burrs in one light stroke though. I usually re-burnish once before I re-file again. I have had poor results when I've used stones on my scrapers. I do get shavings (NOT dust). The turned burr is at least as important as the sharp edge. The burr (or hook) acts as a cut-depth limiter and keeps the scraper shaving smoothly and taking fine shavings. Broken glass is a very poor substitute and hazardous too. If you've never used a properly sharpened scraper you'll be amazed when you try one. A plain edge of any sharpness just does not have the architecture to do the same quality job. These things are really quite easy to sharpen but there is always a lot of poor advice when these questions are posed on public forums like this... thus people cntinue to suffer from confusion and struggle (unknowingly) with dull and semi-sharp scrapers.
Hi Zabo
Here is a tutorial from my website:
http://www.inthewoodshop.com/WoodworkTechniques/PreparingACabinetScraper.html
Regards from Perth
Derek
Here is a link to a blog entry on the card scraper (see the 3/11/08 entry).
http://www.rlmillard.typepad.com
Rob Millard
http://www.americanfederalperiod.com
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 (90 degrees to the stone), 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 (1/4") from the edge of your bench. Run your burnisher along the flat side of the scraper pressing it 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 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 lighter 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 aggressive 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."
I just tried a combination of bigfoot and hammer's method and wow it works. No more tedious honing from courser to finer stones. Just draw-filing and burnishing, works fine. I know this will upset some of the traditionalist but hey it works. THANKS to everyone for their replies.
ZABO
Edited 7/16/2008 11:47 am ET by Zabo2
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