Lapping Japanese Water Stones... a discovery.

Diomedes Industries

Diomedes Industries

Joined
Mar 19, 2007
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So, I needed to lap my 800 grit Japanese water stone and I was fresh out of 400 grit sandpaper that I normally put on my Granite Block (Machined to some extremely flat tolerance). So, after fighting a smaller scrap of 400 grit - I just took the paper off the block...

What I found was that the granite block was plenty abrasive enough to lap the 800 grit stone to absolutely flat.

So, from now on, I am just going to be lapping my stones (uh huh huh huh huh) with that granite block.

I just bought it recently at Granger for less than 50 dollars.

TF
 
when using abrasive paper to dress a stone down, the paper should be glued down somehow to keep it from bunching up which would cause the paper to bunch up in front of the stone and cause it to be uneven. a concrete block is another good thing to use and cheaper. i can see one problem with using the block only to dress the stone. over time its going to wear the granite down and make it uneven. you should go back to using sandpaper on it.
 
Understood Richard, it is just for personal sharpening, and my obsession with blades is slowing some - I think I will do fine for now - I am sure it will take me a while to wear down granite. ;)

I normally do tape my wet/dry paper down - but I was trying to be quick... never good. ;)

TF

TF
 
richard j said:
when using abrasive paper to dress a stone down, the paper should be glued down somehow to keep it from bunching up which would cause the paper to bunch up in front of the stone and cause it to be uneven. a concrete block is another good thing to use and cheaper. i can see one problem with using the block only to dress the stone. over time its going to wear the granite down and make it uneven. you should go back to using sandpaper on it.
Click to expand...

Putting some water between the paper and the flat surface creates a bit of a "vaccum" that also keeps it from bunching. Plus you don't have to clue anything.

Only problem is I've encountered is that as the water dries, some brands of sandpaper will "curl" up and you have to tape the corners down.

Still I find it easier than working with glue, because once you put glue on a flat surface you need to do all sorts of things to get it off so it'll be flat again.

What kind of block is this again? I might be interested in getting one, at the moment I use a flat piece of composite board off of an entertainment center. I'm sure a granite block would be easier to work with.
 
its a granite surface plate normally used in machine shops for layout work and for checking to see if a machined or ground part is flat or if it has a taper by using a dial indicator. you can use a thin oil so evaporation wont be a problem. you can find them at grizzly imports or you might try harbor freight. you can also google granite surface plates.
 
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If your surface plate has two ledges (one on each short end), you can clamp a sandpaper sheet to the plate. Take a 1" X 1/8" strip of 1095 as long as your plate and bend it into a slight curve. Harden the steel to make a spring. Slide a bicycle inner tub over the spring and clamp the sandpaper at 1/3 its width. Work on the wide side and reverse the paper when you need fresh abrasive.
 
richard j said:
its a granite surface plate normally used in machine shops for layout work and for checking to see if a machined or ground part is flat or if it has a taper by using a dial indicator. you can use a thin oil so evaporation wont be a problem. you can find them at grizzly imports or you might try harbor freight. you can also google granite surface plates.
Click to expand...

Oh, yeah, I always thought those were called surface planes for some reason. I tried to look for one when I first considered getting something to flatten stones since I recalled using them to check for flatness.

Well, now that I know what it's called and everything I should be able to find one easily.

http://www.woodcraft.com/Catalog/Pr...=7535&ss=993f1e86-3fa7-402e-bfa5-bae757a6322a This one looks pretty good
 
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