To Lap a New Hone...

Does everyone know that you need to lap/flatten a new hone right out of the box before use?

I've read a lot on razor forums where people use stones right out of the box without lapping them first. I've seen it in pictures and noted many making comments about this. I also know from talking to my customers and knife sharpeners that they too do this as well. It seems like this bit of information has been lost or never known, I can't say which but that doesn't matter.

The fact is that a Japanese synthetic waterstone comes with a sort of surface crust that needs to be broken through and lapped away. Not to mention that many aren't flat and lots have ink and even stickers on the surface that need to be dealt with. If you don't break through the surface of some stones they actually won't work almost at all. I've seen it countless times where a sharpener buys a new set of pricey stones just to be left scratching his head after the first use pondering how these things could be so highly regarded when he can't get them to do anything decent for him. He then thinks that either the stones suck, the people who gave the advice on the stones are idiots, or he doesn't know what he's doing -all very frustrating things to deal with.

I have found that there are some exceptions to this rule but they're few and far between so when you get a hone lap it and all will be good.

Remember, I'm talking about Japanese synthetics, not naturals or any other nation's sharpening stones, they may well all be different in this sense.

Dave

I respectfully disagree. I recently bought Naniwa 5 and 8k hones. I used both right out of the box, without lapping, and honed up a batch of 16 razors. They all came out great. Lapping out of the box, though probably a good idea, is not necessarily necessary. As with all things, there must be a percentage of hones that are flat or close enough to flat to use straight away, and others that are not.

I always lap a new hone regardless of origin. I feel better doing that and in the scheme of things it is doing no harm and maybe a lot of good.

I lapped my Shaptons right out of the box using the grid pattern. I had read it was a good idea to do so, so thats what I did...!

Now I only lap them to clean off the swarf, or if I have done a lot of honing and I want to ensure that the stone is flat.

Place a ruler on the 2 diagonals of the hone and use some light, if the light passes to the other side it needs to be lapped. (make sure the ruler is straight, I know for experience not all are :gth)

I used my naniwa 8k out of the box with no problem, the 5k needed lapping

How can you guys use a Naniwa SuperStone OTB with residual sticker glue on the surface?

I know first hand that these stones will act better when lapped a few times too. The Naniwa Choseras are the same way, in fact the Naniwa Chosera barely work at all until lapped.

Flatness is only one reason to lap a stone.

Another thing worth noting is that the edges of stones should be rounded after flattening has been done. If you don't do this your razor will be elevated by the high corners and not be allowed to make full contact across the bevel. In the knife sharpening world we call this "sharpening on rails".

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Originally Posted by DaveMartell

How can you guys use a Naniwa SuperStone OTB with residual sticker glue on the surface?

I know first hand that these stones will act better when lapped a few times too. The Naniwa Choseras are the same way, in fact the Naniwa Chosera barely work at all until lapped.

Flatness is only one reason to lap a stone.

Another thing worth noting is that the edges of stones should be rounded after flattening has been done. If you don't do this your razor will be elevated by the high corners and not be allowed to make full contact across the bevel. In the knife sharpening world we call this "sharpening on rails".

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I bought mine from Fine Tools in Germany and got the 20mm thick superstones with no base so my honing surface is the opposite side from the sticker. Lapped them anyway as it makes no sense to me not to. I also routinely round all edges. IME if I take a Shapton Pro or a Naniwa superstone out of the cabinet that was lapped the day before ....and throw a pencil grid on it will not be absolutely flat the following day. Some will be close and others further away but I lap mine every time I use them.

I use a pencil grid initially and as I am working with a stone I lap the swarf away without the grid using the method of judging by color. Whether all of this is necessary is debatable but it is what I do because it makes me feel good. :)

I would at least check for flatness as yoshida said, and if necessary lap it as Jimmy advises.

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Originally Posted by DaveMartell

How can you guys use a Naniwa SuperStone OTB with residual sticker glue on the surface?

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Well, I peeled off the sticker, added some water, and ran the razor over the surface of the hone using a normal honing stroke.

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Another thing worth noting is that the edges of stones should be rounded after flattening has been done. If you don't do this your razor will be elevated by the high corners and not be allowed to make full contact across the bevel. In the knife sharpening world we call this "sharpening on rails".

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This makes no sense to me. If you lap the entire surface of the stone, the edges will be at the same height as the middle. "High corners" means that the hone has not been properly lapped.

Please don't hold me to this. But, I believe I remember Lynn Abrams saying he lapped the Naniwa Superstones when received. But, again if I remember correctly, the reason was that he thought the consistency of the "stone" at the top of the hone was not consistent with the rest of the hone. He had to lap thru the thin layer to get to the regular consistency.

But, heck! It might have been anyone who said that... :)

Whoever said it, it makes sense to anyone who has poured concrete. Gravity pulls particles downward before the concrete sets. But, I wander...

If true, I doubt it would be very critical.

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Originally Posted by holli4pirating

This makes no sense to me. If you lap the entire surface of the stone, the edges will be at the same height as the middle. "High corners" means that the hone has not been properly lapped.

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Check your flattened stone by running your finger/thumb from the middle of the stone out and over the edge and you'll feel the high edges. When you sharpen a knife on a stone that hasn't been rounded on the edges the stone will only show black streaks on these high edges - nothing in the middle. This means that you are only providing 1/4" of stone surface to the knife when you should be providing the near full width of the stone. This isn't something that's easily seen or apparent when razor honing since razors don't bridge across the width of the stone the same way that knife does, however, on thin width stones (sometimes used) and in certain techniques the edges of the stones are coming into play more than others. I can't tell you how many times I've seen people proclaim their dislike of a stone that they had high edges on only to fall in love with the stone later on when the edges were rounded for them. The reason for this is that they are using more surface area of the stone after the edges have been rounded. The question is then often asked about why they don't notice this on other stones that they lap the same way and love? My answer is that some stones cut faster than others and the small amount of contact area presented by some stones doesn't matter where it matters very much on others.

Correct me if I'm wrong here - after you lap a hone, the top surface is flat. On a flat surface, all points lie in the same plane. Therefore, the sides of the hone are at the same height as the middle of the hone.

I don't know what you mean by "bridge," but I have hones that are narrower than a razor and hones that are wider than a razor, and I've never had any issues with a razor only contacting the edges of a hone on any lapped hone. I cannot imagine why a knife with a straight or smiling edge would act any different than a razor with a straigth or smiling edge, but I don't hone knives, so I'll take your word that there is a difference. Knives may indeed need rounded edges, but razors do not. The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

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Originally Posted by holli4pirating

The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

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Early on Randy told me to round the edges so that if there was a minuet chip in the edge of the hone it wouldn't catch the edge of the razor and chip it. I do that as soon as I get any hone. Funny thing is I have bought or traded hones from knowledgeable honers who didn't round their edges or flatten those hones. :thinking: I didn't know what to make of that but I would rather be safe than sorry so I flatten and round no matter what rock it is.

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Originally Posted by DaveMartell

Does everyone know that you need to lap/flatten a new hone right out of the box before use?

I've read a lot on razor forums where people use stones right out of the box without lapping them first. I've seen it in pictures and noted many making comments about this.

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really? this is all news to me. can you point out the pictures which show unlapped hones? for as far as i remember lapping the hones has been considered standard and necessary practice on this forum. as a matter of fact josh earl made a photo tutorial a year or two back of lapping with sandpaper (the cheap version) and it's been part of the wiki for a long time now.

for example lynn has repeatedly posted that the current production nortons require some good lapping to go past the more grainy top surface.
when i just bought my naniwas last year glen told me to give the 1000 good lapping several times leaving it to dry in between, it certainly started working properly after that.

My Naniwas SS are combination stones, they came without any sticker on them and without any residual glue. They were bought as new and looked like it, they weren't lapped when I got them.

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Originally Posted by gugi

really? this is all news to me. can you point out the pictures which show unlapped hones? for as far as i remember lapping the hones has been considered standard and necessary practice on this forum. as a matter of fact josh earl made a photo tutorial a year or two back of lapping with sandpaper (the cheap version) and it's been part of the wiki for a long time now.

for example lynn has repeatedly posted that the current production nortons require some good lapping to go past the more grainy top surface.
when i just bought my naniwas last year glen told me to give the 1000 good lapping several times leaving it to dry in between, it certainly started working properly after that.

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I don't have to search far for this, there's guys right in this very thread who have admitted to it - the OTB Naniwa guys. Just because people have delivered the message over and over doesn't mean the point has been made. I myself talk about this on Knifeforums util I'm blue in the face yet upon posting this very same topic over there we have a bunch of people admitting that they never heard it before.

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Originally Posted by holli4pirating

Correct me if I'm wrong here - after you lap a hone, the top surface is flat. On a flat surface, all points lie in the same plane. Therefore, the sides of the hone are at the same height as the middle of the hone.

I don't know what you mean by "bridge," but I have hones that are narrower than a razor and hones that are wider than a razor, and I've never had any issues with a razor only contacting the edges of a hone on any lapped hone. I cannot imagine why a knife with a straight or smiling edge would act any different than a razor with a straigth or smiling edge, but I don't hone knives, so I'll take your word that there is a difference. Knives may indeed need rounded edges, but razors do not. The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

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Absolutely true - the surface will be dead flat but those edges won't. I don;t have a reason but I do have theories which mean nothing. All I know is it's a fact.

BTW, no one has to agree with me on this, I could care less. I'm simply offering up some insight gained from an immeasurable amount of stone work. If I'm coming across as a "know-it-all" then I apologize, I just wanted to help where I can see a problem.

Dave