Which lapping stone to get?

[Slash McCoy]

You can get a polished marble tile from a building supply. We get ours from Home Depot, mostly. They sell a 4" x 12" edge tile with one edge radiused, called a Bullnose Tile, for $5, and we use that with lapping film to hone razors on. You can get a 12x12 tile for lapping stones with. Get some LocTite Spray Adhesive, and lightly spray the back of your wet/dry paper. Carefully stick it on the tile so that it goes down stretched smooth. You don't want even the slightest bubble or wrinkle in it. Draw a grid pattern on the stone with a pencil, and work the stone back and forth corner to corner on the paper until the grid is gone. Switch to a finer paper and do it again. Go with at least 1000 grit paper for the final lapping. The scratches left by the paper in the stone surface will wear smooth quicker if they are made by finer abrasives. Initially, you might find that your coti doesn't finish well, but after you get a bit of wear on it, you are golden. One way to wear in a freshly lapped coti is to hone all your kitchen knives on it with a good heavy slurry. You can also just rub it in with your slurry stone, for that matter.

Just as good as the marble tile is a piece of heavy glass. Glass coffee table tops work great for this. Also keep an eye out for the sink cutout from a polished granite countertop. These are usually flat enough to do a good job, too.

The granite lapping plates sold by tool and sharpening supply vendors work great, and they are a little flatter than the improvised plates listed above, but then again, they cost more. Your priorities.

 

[hokahay]

I bought one of these on sale. Works great and big CDI factor to boot!

http://www.woodcraft.com/product/2004864/7535/granite-surface-plate-9-x-12-x-2-a-grade.aspx

Here I see they have a kit. Add a woodcraft CHUG and a mini and your good to go with waterstone setup.

http://www.woodcraft.com/product/2004486/36508/intermediate-waterstone-kit.aspx

Add this for a slurry stone.

http://www.woodcraft.com/product/20...-mini-diamond-sharpening-stone-extrafine.aspx

And about 20 sheets of 400 wet dry.

It's the zen of honing! Flattening.

 

[jeness]

400? 40 grit until flat, than smooth it with one sheet of 180, and one 400, done

 

[hokahay]

I'm basing on a 325 DMT. Woodcraft is providing 220 in the kit. I've also seen others that are using a progression to a finer grit than you suggest. I've been using 320 here. I've did an 800 grit follow up on my chug and the 8000. Now I just need to go 8000 up on my new Le Grelot and see if the flat extra effort results in a better edge. It was a pretty good edge before the flat obsession revealed itself.
All I have is 180 and up right now.

Ahh, the zen of flattening.

 

[Malacoda]

wet/dry sandpaper on a flat marble or granite plate is a cheap way to lap...the DMT 325 is a great lapping tool

+1

That's all I use.

+1 as well

Stopped at Home Depot one day...

1. went to the hand tool section and picked up a steel square (e.g the ruler that is shaped like an 'L')
2. Carried it over to the tile aisle
3. Grab a 1'x1' glossy marble tile
4. Placed one edge of the square on the face of the tile to make sure the tile surface was true (i.e. with the 'L' standing up on the shiny face of the tile, I could not see any light between the edge of the rule and the tile face)
5. Put the steel square back where I found it
6. Bought the tile for ~$4
7. Swung by Autozone and picked up a couple of mixed grit packs (220, 400, 800, 1000) of 9" x 11" WetorDry sandpaper for ~$6 each (Home Depot here only stocks the lower/courser grits used for woodwork. Automotive stores carry higher/finer grits because they're used for autobody work.)

...and bingo, done deal - had a perfectly fine lapping set up consisting of multiple grits for about half the price of one DMT.

Set the tile on a old bath towel. Wet the tile a little (for suction to hold the sandpaper in place), set a sheet of sandpaper on it, wet the sandpaper, and it's off to the races. Have used it to lap several j-nats and cotis to great success.

IMHO, of your looking for a cheap, flexible, quick lapping set up, it can't be beat.

 

[tomjr]

I bought one of these on sale. Works great and big CDI factor to boot!

http://www.woodcraft.com/product/2004864/7535/granite-surface-plate-9-x-12-x-2-a-grade.aspx

i got on of these they do work well. tom

 

[Doc226]

i got on of these they do work well. tom

By ton do you mean number or weight? LOL

 

[life2short1971]

My next lapping plate will be an Atoma.

Mine too. DMT quality is not what it was 2 years ago.

 

[Gamma]

Mine too. DMT quality is not what it was 2 years ago.

I just killed my 325 Dia. I still have a 220/325 Duo - but the Atoma on the horizon.

 

[life2short1971]

I killed a 325 Bought a 220 and had it exchanged for warpage and the second is not much better and there is also one side where the Grit leaves much deeper scratches than the rest of the hone. My 600 is not as flat as my original 325 either.

 

[jeness]

I have the same experiences with DMT too. My 400 grit Atoma is flatter, sticks less, lighter, and feels better in use too. They simply do not compare after you have used one. I tried about 5-6 DMT-s before I bought an Atoma, and I have never looked back.

 

[joshua1970]

how is this Atoma? a 2 sided course/fine (#300/#1000)

http://www.amazon.com/Diamond-Two-S...?ie=UTF8&qid=1349402506&sr=8-3&keywords=atoma


just got more amazon points, so thinking the DMT 325 or the above (if it would be appropriate for lapping)

 

[Drybonz]

I got one of the small 600 Atoma pieces from CKTG. I use it to clean off my Shaptons after a use, and I have a DMT Duo that I use for full lapping. Biggest problem with the DMT is stickage. The Atoma is a little nicer to use, but leaves a lot of light scratches. I use sandpaper on granite sometimes too, but that can be a bit slow and clunky. It's the best way to prevent scratches, though. I guess there are pro's and con's to each method.

 

[jeness]

Thats strange. My 400 grit Atoma left a perfect surface from the first time I used it, but I lap only choseras and naturals, maybe GS stones are different, but it didn't scratch even hard Jnats. Maybe you are using a bit too much pressure while using it? The smaller surface scratches deeper used with the same pressure as the bigger stones.

 

[Drybonz]

I have experimented with it a bit. I started with a 400 but the scratches were even worse. The 600 isn't too bad at all. I have to use almost no pressure with it and just glide the stone around. I use it to clean off the steel after a honing session. The scratches are not deep at all, and don't affect honing a bit... it just isn't that nice smooth surface like when lapping with sandpaper. Ultimately, I'm happy with the Atoma. Its best feature is that it doesn't stick to the hone at all.

 

[alx gilmore]

I use the Atoma #400 for lapping and then switch to the #600 for surfacing smooth followed by a tomonagura. For raising a slurry for honing I use a worn out #600. If any of you think that using a worn out diamond plate for raising a slurry is wasting your stone, I have a stone and an Atoma plate to send you if you promise to stick to it, and count strokes and the time to see how long (days or weeks) it takes to actually wear down a hard Jnat asagi. The amount of stone surface removed in raising a light slurry is in the microns range, not mm or inches. Alx

 

[Tim Zowada]

I use a DMT D8C for everything except my Eschers. I milled grooves across the surface of the D8C, to help break the surface tension.

For the Eschers, I use Grit Silicon Carbide sand paper on a surface plate.

I hope this helps.

 

[boar.master]

I also need a DMT lapping plate to lap my Norton 1k.

 

[WoodfordReserve-Neat]

wet/dry sandpaper on a flat marble or granite plate is a cheap way to lap...the DMT 325 is a great lapping tool

That's what I use for lapping. Also, for taking chips out of a blade edge before resetting the bevel.....

 

[bad-bryce]

in the end I bought duo sharp 325/1200 grit. the 325 leaves some bad scratches but I use the 1200 too smooth it out. now I just do touch up with the 1200.