Replies

1. 
   Bob_Van_Dyke | Jun 10, 2007 07:50am | #1

   Rick- In my school the card scraper is the tool of choice for surfacing any hardwood and the prep of the scraper is not all that difficult.
   After jointing the edge with a 10" mill bastard file you need to lap the faces of the scraper- but only near the cutting edge. I use a plastic jointer push block held so that my pressure on the block is right behind the edge of the face I am working on. I do that on both faces along each long edge. And don't sweat it- It does not have to be perfect! it is not nearly as important as lapping the back of a chisel or plane iron.! After the faces are lapped (BTW- I spend a total of two minutes doing that on a new scraper) then you dress the edge that you filed. Go from your coarsest to your finest stone. Now you are ready to burnish the edge to form the burr.
   My favorite stones for sharpening scrapers are diamond stones. They cut quickly, they are flat enough for scrapers and (contrary to the manufacturer instructions) I use them dry- so it is much easier to hold when lapping. I also use a block of wood as a guide when I am dressing the edge of the scraper- works great on a diamond stone but would ruin any other stone (especially a Japanese water stone).
   If you spend more than 5 minutes start to finish then you are spending too much time. I find that most people blow it because they don't file the edge enough in the initial jointing and then they don't burnish it correctly.
   Good luck- once you get it you will never use your random orbit sander again!
   Bob Van Dyke

1. 
   Thorny | Jun 10, 2007 09:56am | #2

   Bob, thank you for your very helpful and informative response. Allow me a follow up or three, if you will.On the diamond stones: What grit stone would you start with for initial lapping? What intermediate (if any) and finish grits would you then proceed to? Do you strive for a mirror polish or something less than that when you lap? How long might a hook edge last before one has to restore it? And in restoring it, I presume one must return to the mill file and continue as before, no? Finally, I don't suppose alder is a hard enough hardwood to yield satisfactory results whilst using a card scraper. Thanks again!Rick

1. 
   Bob_Van_Dyke | Jun 11, 2007 03:45am | #3

   in answer to your questions- in order:
   the diamond stone grits? don't know the numbers- don't pay attention to them because they don't equate to the numbers in other sharpening systems (none of them do!)
   so- coarse, medium and fine
   The mirror finish might happen one day- but probably not today so lets get the tool going and cut some wood. the "mirror" does not seem to be that important.
   I always re-burnish after 5 to 10 minutes use. or- as soon as you feel that the edge is not as sharp and you are not getting great shavings. If you put off re-burnishing too long you wear down the edge prematurely and then you have to go back to the beginning- files, stones etc. I can usually re-burnish 5 or 6 times (X 4 burrs)which equals a decent amount of work before going back to re-sharpening from the beginning.
   Have never used alder so I cannot say- woods softer than poplar don't scrape well- cherry, walnut, maple are fine- you should see ebony off a scraper!! its beautiful!
   btw- when I sharpen one scraper I sharpen all of them -I would never have less than 3 or 4 ready to go
   best
   Bob Van Dyke

1. 
   Thorny | Jun 11, 2007 07:25am | #4

   Thanks again, Bobm, you've been very informative.

1. 
   peter28 | Jun 12, 2007 07:22pm | #5

   Thorny,

   FWIW; I've seen and used scrapers Bob has sharpened. I don't know of anyone who does it better. He can actually shave the hair off his arm with them.

   Follow his lead. You'll be amazed at the results.

   Peter