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Section 6 - 1, How to lap/flatten your hone.

In order to get your hone to work, it simply MUST be completely flat. Don't misunderstand, or take this lightly - honing with a hone that is not completely flat will simply waste your time and wear down your hone... and your razor. Without the hone being completely flat, you aren't honing the blade at the proper, and consistent angle, and are actually doing more harm than good, and rounding the edge of the blade. Just because your hone is new, doesn't mean it's flat - do yourself a favor, and ALWAYS flatten a new hone, and flatten it on a regular basis. Every few razors you hone - a quick/easy lap of the hone will flatten it, and will require minimal effort, so lap, and lap often. It's better to do a quick 3-4 pass lap/flatten every time you hone and be certain you have a perfectly flat working surface, than to lap once in a blue moon, and have to really lap the heck out of your hone.

The object of flattening your hone is to take a perfectly flat, yet abrasive surface (IE: plate glass with abrasive papers, or a DMT Diamond Plate) and rub the hone against it (using no pressure) until the hones surface is as flat as the perfectly flat surface. The methodology is quite simple - the parts of the hone that are above other parts of the hone will be worn away until they touch the most inward, or deepest portion of the hone that is not flat, thus flattening the entire hone.

Note: Not all hones need to be flattened. Incredibly hard Ceramic Hones such as the Spyderco Extra Fine will show almost NO wear after a tremendous amount of use - however ALL water stones need to be flattened, and on a regular basis.

The necessary gear...
Well, there are numerous ways, and different individuals have different methods of doing so, some choose to use abrasive papers and plate glass, others use special flattening stones, and some use diamond plates. Personally, I find Diamond plates to work significantly better than any other method, and to boot, it is much, MUCH quicker, easier, and mess free to do with Diamond Plates. The particular plate I use, and the one that will be used in this tutorial is a DMT model D8C - which I choose both for it's size (it is large enough to accommodate all of my hones) and it's effectiveness with ANY grit of hone, and a hone made of any material. Don't pay any attention, or worry about the D8C plate being too coarse to use on a high grit, superfine hone, as the DMT will leave no scratches in your hones, nor will it leave any coarse abrasive compound in your hones. This process can be used whether you are using abrasive papers, flattening stones, etc.

D8C Packaging...
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DMT D8C plate mounted to a universal (rubber) hone mount (The hone mount isn't necessary, as the diamond plates come with 4 small rubber numbs you can put on them so they don't slide around, but the universal hone mounts are inexpensive, and make the process easier)...
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In this example, I am going to flatten the most versatile, common and widely used straight razor hone - the Norton 4K/8K, as that is what most of you will be lapping as well.

Here is the DMT D8C mounted to the universal rubber hone mount, with a Norton 4/8K on top of it to show the size of the DMT VS the Norton for reference...
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Now, how do I lap/flatten my hone with the above gear?

Step 1 - Soak your Norton 4/8K for about 15 minutes or so, as if you were going to use it to hone a razor, and while the hone soaks, put your DMT Diamond Plate on a stable surface that you don't mind getting wet - and locate a pencil.

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Step 2 - After the hone has soaked for about 15 minutes, take the hone out of the water, and use your pencil to draw on the hone - checkerboard pattern, back and forth, diagonal - whatever pattern you use or prefer, it doesn't matter - so long as the pattern covers a large portion of the hone and is on all of the edges/corners. In this example, I am drawing on the white, 4K side of the 4K/8K. (Note: if you are using a 2-sided hone, you have to lap/flatten BOTH sides using the same process)

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Step 3 - Put water on the DMT D8C plate, and place the hone on the D8C plate with the pencil drawing side of the hone, face down on the diamond plate.

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Step 4 - Move the Norton back and forth across the diamond plate (circular motions as well will work, or a combination of the two) while being careful not to add ANY pressure to the hone - let the diamond plate to the work. In a short period of time, you'll start to see the water turn milky white (based on the color of the hone, the color can/will be different, so for the 8K side of the norton, it would be a yellowish milk) which is showing you the Diamond Plate is doing its job, and leveling the Norton by removing the areas of the hone touching the plate.

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Step 5 - This is where the silly pencil markings come in. Periodically pick up the Norton off of the Diamond Plate and check the pencil markings to see if, and where they exist. The object of the exercise is to continue to lap the Norton against the diamond plate until there are no more pencil markings left. As you can see below - SOME of the pencil markings were lapped right off, where as others were more stubborn and took a bit to become lapped out. This means my hone was NOT flat, as if it were, the pencil marks would quickly, easily and uniformly disappear. Once all of the pencil marks are gone, it means the hone is perfectly flat, as ALL portions of the hone are now touching the lapping plate - and the lapping plate is flat!

Pick up the hone, you should see a milky residue left from the hone on the plate...

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Notice in the picture below where the pencil markings are? This means the part of the hone with pencil markings is not touching the lapping plate, thus the parts of the hone that have NO pencil markings on them must be worn down to the point where the parts of the hone with pencil markings are touching the perfectly flat lapping plate - thus making the hone perfectly flat...

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Almost there...
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Here it is... perfectly pencil mark free, perfectly flat - and perfectly ready to get to work!

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Again, remember to flatten your hones often! A flat hone is a useful hone.

PROCEED TO THE NEXT SECTION OF THE GUIDE - Section 6 - 2, Creating the initial bevel....

BACK TO THE TABLE OF CONTENTS
 
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Joel,

This guide is an excellent resource. You might consider adding links for where products can be purchased or maybe others would consider creating a separate page as part of the guide where they can fill in prices by category of different straight razor gear.

Thanks for doing this,

John
 
I would add that if the pencil marks didn't come off immediately (i.e. the hone was not flat when you started) that when you finish the process above you repencil the hone and clean off the lapping plate and lap it one more time, just to make sure. This may not be as big of an issue if you're using the DMT plate as it is if you're using sandpaper on a marble tile, but I've seen cases where the marks didn't immediately come off when I did it a second time like this - the hone was very close to flat but not quite there yet despite the pencil marks having come off in the first attempt. If you're using sandpaper then the likely culprit is the sandpaper getting sucked off the counter into the hollows of the hone as it goes over and wears the pencil marks off even though they're not actually touching the hard lapping surface. Additionally I think the abrasive slurry gets surprisingly turbulent in those same hollows and can wear the pencil marks off the hone as well. If you're gonna go to all the trouble then you may as well get it properly flat.

I also recommend lapping your stones before every honing session. It may wear them down a little faster but it guarantees that your hone isn't the weak link in the process.

I'm also a fan of the Shapton lapping plates. I've got the iron one (they also make a high-tech diamond-on-glass one), but both have deep grooves in them that prevent the false-flatness problem I described above. With these plates once the pencil marks come off then it's really done. And the iron plate has a rubber cover that lets the lapping plate double as a hone holder, which makes for one less thing to clutter up the countertop and makes lapping before every session less of a bother.
 

Tony Miller

Speaking of horse butts…
mparker,
Excellent point. On a larer granite surface plate using Joel's method is easy and fast and getting that flat surface the first time s easier due to the base being larger than the hone being lapped.

On a system like this with a small or equal size base one could actually over lap some areas and go deeper than the initial flat created so when the final pencil marks leave the surface other areas are now in a minus condition or "lower" than the flat just achieved. When done I also give it one more cross hatching of pencil marks and another pass over the base to see if all now leave together as they would on a uniform planner surface.

Tony
 
This thing is great. I will never use the other methods I have again. It will lap anything fast, even those hand held (swaty like hones) I hated lapping. I am lapping any thing I can find.

I did the pencil grid work under running water. After the stones dried , I went over them again, and yes the extra step with this thing is worth it. With the dry step you can see where the high spots are. Lap a bit, look at the progress, brush off the DMT and repeat, if needed.

Just for the heck, I honed a WB chopper with it that was going to take a day the old school way. In no time at all, done Be careful its fast.

Thanks
 
This thing is great. I will never use the other methods I have again. It will lap anything fast, even those hand held (swaty like hones) I hated lapping. I am lapping any thing I can find.

I did the pencil grid work under running water. After the stones dried , I went over them again, and yes the extra step with this thing is worth it. With the dry step you can see where the high spots are. Lap a bit, look at the progress, brush off the DMT and repeat, if needed.

Just for the heck, I honed a WB chopper with it that was going to take a day the old school way. In no time at all, done Be careful its fast.

Thanks
Great to hear it worked great for you!

The Shapton lapping plates are superlative as well, but they can be quite expensive. For $35, it's pretty hard to go wrong with the DMT!
 
Who's to say the diamond plate is flatter than the hone starts out? :confused:

DMT Diamond plates have a flatness guarantee of +/- 0.001" - which is MORE than flat enough for what we're doing :smile:

Personally - I am a BIG fan of DMT's over Norton's and will probably be selling my norton soon. DMT plates NEVER need to be lapped/flattened, are easier to use, cut faster, etc etc. I get much better results with them as well. :smile:
 
DMT Diamond plates have a flatness guarantee of +/- 0.001" - which is MORE than flat enough for what we're doing :smile:

Personally - I am a BIG fan of DMT's over Norton's and will probably be selling my norton soon. DMT plates NEVER need to be lapped/flattened, are easier to use, cut faster, etc etc. I get much better results with them as well. :smile:

DMTs over Norton diamond stones? How would you lap/flatten a diamond stone? I'd imagine it's pretty difficult.
 
Re-read what you quoted :wink: - they don't need to be lapped. :smile:

I must be confused. I was thinking DMT was a brand and Norton was a brand, and they both made diamond stones. And I thought you said you preferred DMT, one of the reasons being they don't need to be lapped.
 
I must be confused. I was thinking DMT was a brand and Norton was a brand, and they both made diamond stones. And I thought you said you preferred DMT, one of the reasons being they don't need to be lapped.

DMT and Norton are 2 brands - however DMT only makes diamond hones - and Norton doesn't make any diamond hones. Norton's (specifically the ones we use for honing razors) are synthetic waterstones, which wear pretty quickly. The DMT's as shown above (which lapped the norton) are a solid nickel plate with diamond embedded into the top surface.

Hope this helps...
 
DMT and Norton are 2 brands - however DMT only makes diamond hones - and Norton doesn't make any diamond hones. Norton's (specifically the ones we use for honing razors) are synthetic waterstones, which wear pretty quickly. The DMT's as shown above (which lapped the norton) are a solid nickel plate with diamond embedded into the top surface.

Hope this helps...

Finding this threw me off. So you can use a DMT to lap a Norton, and then use the Norton to hone, or just use the DMT to hone?
 
Finding this threw me off. So you can use a DMT to lap a Norton, and then use the Norton to hone, or just use the DMT to hone?

Yikes - looks like I was wrong.... I didn't know Norton made diamond hones!

Ok - to lap a stone - you need a stone that is HARDER than the one you're lapping/flattening - so in this example - I am using a DMT diamond stone (diamond is the hardest material) to lap a Norton Synthetic waterstone. By lapping the norton with the DMT, it creates a flat surface on the norton, which allows me to use it on the straight razor in the most efficacious manner possible.

Now - that specific DMT used in this example is a D8C and is 325 grit. 325 grit on a straight razor is WAY too coarse, unless you're trying to take out a nick, setup a bevel, or do some serious work on an ebay special. You CAN hone a razor on the DMT D8C plate - but again, it's way too coarse to use as a finishing stone, so you'd want to follow up with finer grit DMT stones, such as a DMT fine, Extra fine, then Extra Extra Fine (8000 grit) stone.

In the example above I lapped the norton with the DMT plate - and in later examples use the Norton to hone a razor using the 4000 grit side to set the bevel, and the 8,000 grit side to polish the edge - as the razor was in good shape.

Hope this helps...
 
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