Thread: Hi guys, Need help Re: lapping my new naniwa stones What to buy, what to use etc.

Hi guys, I just got naniwa 1k and a 3k/8k combo stone, need to lap them flat, I picked up a King lapping stone for 20 bucks but it feels reallly course and doesnt feel that flat so I'm not too keen on using it, I bought a black glass board which seems pretty flat to use the 320 grit wet/dry sandpaper on, but when I did that method afterwards when honing it seems the stone isn't flat still, should I draw antoher pencil grid and re do it ? can someone explain the method to me in detail in case i'm missing something?

I'm getting a Dmt diasharp but the store near me can't find the ones they were meant to have in stock so now I've ordered one it's coming soon. but I really want to start learning to hone asap

You can keep trying with your sandpaper until your grid disappears. In my experience, it can take a while using sandpaper. With a DMT coarse plate it will flatten your stones pretty fast. So either you wait for your DMT or put in some more elbow grease and flatten them with your sandpaper.

I ran into a similar problem when I tried lapping with sandpaper on glass. I was allowing the leading edge of the stone to dip at ether end of the sandpaper. Creating a concave surface. I would wait for the dmt. Mostly because it wont leave grit contamination in the stone. However you likely would not have horrible results if your stone was only close to flat.

Jonathan

personaly I bought a piece of quartz that's 12''x9''x2'' that's made for lapping (I have a thread about it if you would like to see pics and paperwork on it). I believe it was aRround 40 (probably less but I'm gonna say 40 just incase) from woodcraft.com and its within .001mm of bieng perfectly flat. Then I get it wet, throw a sheet of 220g wet/dry sandpaper on it aNd then run my faucet on it while I lap my hones. But I have been told to not get slurry under sandpaper or it will eventually wear uneven. But that's what I use and they sell a 1" thick stone and lookig back that's what I should have gotten because mine (bieng 2" thick) weighs arround 40 lbs. And they have super fast shipping. I highly recommend going this route. Espically if your not gonna mind buying the sandpaper and you don't wanna drop a lot of money on a dmt

Originally Posted by saitou

Hi guys, I just got naniwa 1k and a 3k/8k combo stone, need to lap them flat, I picked up a King lapping stone for 20 bucks but it feels reallly course and doesnt feel that flat so I'm not too keen on using it, I bought a black glass board which seems pretty flat to use the 320 grit wet/dry sandpaper on, but when I did that method afterwards when honing it seems the stone isn't flat still, should I draw antoher pencil grid and re do it ? can someone explain the method to me in detail in case i'm missing something?

I'm getting a Dmt diasharp but the store near me can't find the ones they were meant to have in stock so now I've ordered one it's coming soon. but I really want to start learning to hone asap

Here's a good video on lapping stones.

When you do get your DMT, it's a good idea to run something metallic over the surface for a few minutes in order to remove any diamonds that are sticking out a bit too far from the surface; there will likely be a few, and using the DMT without first breaking it in will leave some odd scratches in your hones. I used the stem/shank of a screwdriver, running it over the entire surface of the DMT, and rotating the DMT so that the strokes are not all in the same direction. I hear some people also just use concrete/pavement on it.

A problem I ran into was that I was bearing down on the stone while lapping. Use the weight of the stone, or a little more....and a lot of patience and water.

As above. Watch your pressure & watch that it's evenly distributed. Using the weight of the stone alone will help.
Also a "pretty flat" glass board ain't real scientific The DMT should improve things.

Most modern glass is Float Glass. It solidifies while floating on liquid metal, it will conform to the local gravity field. That is so flat that most tools could not measure it over the distance usable to lap a hone. A bigger concern is that the glass can flex if it is not on a roughly flat surface potentially introducing measurable curve.

Of course all of that is mostly not a noticeable problem as a razor only sees a small part of the hone at any given time. Just information to inform your choices. A DMT is a very good choice.

Have fun.

Jonathan