I didn't realize how important FLAT is to a hone!

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11-20-2010, 04:15 PM
TheMetatron

I didn't realize how important FLAT is to a hone!

Flat!

I have three ceramic hones from Spyderco for honing my straight razor. The medium, fine, and ultra-fine.

http://spyderco.com/pix/products/med/302M_M.jpg
http://spyderco.com/pix/products/med/302F_M.jpg
http://spyderco.com/pix/products/med/302UF_M.jpg

I've honed my Dovo Special tortoiseshell 5/8 round nose straight razor three times with these hones, as they came from the manufacturer. I was able to get a usable shave, but it just wasn't what I remember that razor feeling like when it was new.

I remember reading on the forums about lapping the hones to get them flat. So, how does one lap a ceramic hone? That stuff is hard.

I wanted something a bit more aggressive than that medium hone to set an initial bevel on my razor, so I bought an EZE Lap 3" x 8" Fine/Medium (800/400) dual grit diamond hone for that task:
http://images.knifecenter.com/knifec...DD8SF_3247.jpg

It occurred to me I could use that to lap my ceramic hones, too. So that's what I did. (This voided the warranty on my hones, I realize) Plenty of water, and went to it on the 400 grit side. The medium hone flattened the quickest. The fine ceramic hone took an hour and several hundred laps to flatten. The ultra fine took about fifteen minutes.

It was pretty easy to see the high spots and the low spots as I was lapping. Since I had used these hones, there was steel deposited on the high spots and to a lesser degree, the low spots. On the diamond plate, the high spots ground off to be perfectly white, making it easy to see how far I had to go.

I was dubious how important the flatness of the hones is for honing a straight razor. I really figured they should be fairly usable and competent from the manufacturer.

Not so. At least not with these Sypderco ceramic hones.

While I was lapping, for comparative feel, I made a few strokes on the hone with my straight razor (no tape on the spine), just to see how it felt and sounded. Wow, you can sure tell the difference when the hone is flat!

The entire edge of the razor is in full contact with the entire face of the hone over the entire stroke. It feels almost sticky, the drag is so smooth and consistent.

The dark pattern of steel left on the hone is now left across the whole face of the hone.

I had a quick look at the edge under my stereo microscope at 35x, and the result from just testing the hones was astounding! Easily the most precise and smooth edge I have produced to date, and I wasn't trying for a finished edge, remember. I was just testing the hones.

This evening I will run the razor through a progression, and have a shave with it in the morning. The shave I had with it this morning was acceptable, but not great. I am most anxious to see how tomorrow's compares.[/quote]
11-20-2010, 04:27 PM
Utopian

If you lap the Spydercos you alter their apparent "grit" size. The only difference between the F and UF hones is the surface finish, which is altered by the lapping.
11-20-2010, 04:40 PM
richmondesi

Personally, I'm not as big on the mathematically flat concept as others. I think honing is in the hands, and while I'm not going around recommending people don't lap their hones, I don't personally worry much about it.

Unless there is a major unevenness, I don't bother...
11-20-2010, 04:44 PM
Utopian

Quote:

Originally Posted by richmondesi

Personally, I'm not as big on the mathematically flat concept as others. I think honing is in the hands, and while I'm not going around recommending people don't lap their hones, I don't personally worry much about it.

Unless there is a major unevenness, I don't bother...

Agreed. Plus, if there is a "major unevenness" in a Spyderco it can be replaced for free since they are guaranteed to be flat within their defined tolerances.
11-20-2010, 04:55 PM
JimmyHAD

Quote:

Originally Posted by richmondesi

Personally, I'm not as big on the mathematically flat concept as others.

Maybe so but for me flat is where it's at. :D
11-20-2010, 05:07 PM
sebell

The Spydercos have an absolutely different feel to them once lapped.
On a brand new UF, I can definitely feel the 'swirls' of the surface finish
on the razor, but it still does the job. A lapped UF feels like glass.

Lapping these hones, to me, is about the surface finish, not the flatness.

- Scott
11-20-2010, 06:40 PM
TheMetatron

Not so sure about the grit being on the finish...

After lapping the fine and ultra-fine stones on the 400 grit diamond plate, their finish is definitely still different. I can also see the difference with my high power microscope.

The little scrap of paper information sheet that came with them said they're made from high alumina ceramic, formed when alumina particles (synthetic sapphires) are mixed with a ceramic bonding agent, then fired to make the final shape. I'd think it is the size of those alumina particles that are determining the grit of the fired ceramic.

As for the flatness, it is the flatness across the stone that I was after, not so much the flatness from end to end.

Before I lapped them, both the fine and ultra fine had clear high spots that were the only places on the hone that were removing metal from the edge. This was evident by the dark black lines that showed those high spots.

Now, they get a uniform grey from the removed steel, showing no high spots. I think this is the main reason the feel is so different. The full blade edge is in contact with the full face of the stone over the entire stroke. This polished the edge much, much faster than the unlapped hones. I'm thinking this must be because of the more constant contact with the hone.

But, the proof will be in the shave tomorrow morning. I gave it fifty laps on the linen side of my Illinois Strop Company 127 strop, and another fifty on the leather side this evening. Beard hairs only grow so fast...
11-20-2010, 06:51 PM
richmondesi

1 Attachment(s)

Here's a picture of one of my stones. You can clearly see the unevenness of it, but I can get really good results in very little time. It's a thin natural stone, or I would go ahead and do a preliminary lapping to level it off. If I did that, I would lose a lot of usable coticule. So, I just use it unlapped with very good results. But, like I said, I feel it's all in the hands...:D This was a 35cm natural combo that split during transit, so the picture is before I hacksawed it down to make two 170-ish naturals (glued the two broken pieces back together. Worked great
11-20-2010, 06:54 PM
Utopian

Quote:

Originally Posted by TheMetatron

The little scrap of paper information sheet that came with them said they're made from high alumina ceramic, formed when alumina particles (synthetic sapphires) are mixed with a ceramic bonding agent, then fired to make the final shape. I'd think it is the size of those alumina particles that are determining the grit of the fired ceramic.

If you check with the company, they will tell you that the two plates are made with the same alumina particles and the same ceramic, and that the only difference between the two plates is in the surface lapping.
11-21-2010, 04:20 AM
randydance062449

Quote:

Originally Posted by Utopian

If you check with the company, they will tell you that the two plates are made with the same alumina particles and the same ceramic, and that the only difference between the two plates is in the surface lapping.

Agreed, I read that the difference is due to them dressing the hone with a 325 grit diamond wheel in different patterns to achieve the different "grit" sizes which is nothing more than a texture on those hones. I suspect that what the OP is experiencing is a change of "grit size/texture" that he has now created in addition to an increase in flatness.

Back to the OP.......
I think you will find that the Spyderco hones work much better when a slurry is used on them. Reportedly, using the Diamond spray from SRD works very well. I have used garnet powder and natural nagura and achieved much better results then using the hones plain.

We don't mean to rain on your parade but rather to give useful information that you can work with.

Hope this helps, :)
11-21-2010, 08:10 AM
TheMetatron

So, what happened, do you think?

I lapped both my fine and ultra-fine ceramic hones with a 400 grit diamond plate. Did I make the fine hone finer, and the ultra-fine hone less fine?

If so, what do you think I can do with that ultra-fine hone? Lap it with the other side (600 grit) of my diamond plate?
11-21-2010, 07:35 PM
randydance062449

What I concluded from reading Spyderco's description was that it is the pattern they create on the ceramic that creates the "grit" size. Thus it will depend upon the pattern you used in lapping that will determine "grit" of your hones. I would suspect that if you used the 600 side and used multiple direction passes that you may end up with a finer "grit". Vertical back and forth, horizontal back and forth, diagonal back and forth, if that makes any sense. North-South, East-West, then diagonal at 45 degrees northeast-southwest, northwest-southeast. Better?
You will simply have to try it to find out. The test is in both how it feels to hone on it and the edge it produces.

Keep us posted on your efforts,:)
11-28-2010, 02:17 PM
TheMetatron

Still, there are unknowns...

I took my ceramic hones, and pattern lapped them with my diamond plate. On the Spyderco Medium (brown) and fine (white) hones, I used the 400 grit side of my diamond plate. On the Spyderco Ultra Fine hone, I used the 600 grit side of the diamond plate.

I lapped a criss cross pattern into all three hones, 45 degrees off each side of the long axis. A only did a few strokes in each of these directions.

Indeed, the cutting ability of the ceramic hones was improved dramatically. Dramatically.

Now the question really is, what the hell is going on with these hones? The scratch patterns I put into the face of the ceramic hones are visible to the naked eye, so the individual striations can't be much closer than 100 micrometers apart. That's a huge distance compared to the size of the sintered alumina particles of the ceramic material.

I think what this did was to make deep ditches where the honing debris can collect, leaving the remaining ceramic surface clean to remove steel. What makes me think this is that my hones feel all the time now, like they did for the first few laps right after cleaning them with scouring powder.

But still, what puzzles me about this idea is that I had the same depth of scratches before criss-cross lapping the hones, only the lapping scratches would have been along the long axis of the hone only.

There's more going on here than meets the eye.

Anyway, I had moved the bevel back behind a couple of dings I had put in the edge with the scales of the razor, and after criss-cross lapping my ceramic hones, the scratch marks on the razor bevel from the 600 grit diamond plate came off with ease. Prior to the criss-cross lapping, I could make hundreds of laps on my ceramic hones with hardly any effect at all on the razor.

Next weekend, the shave will tell a more complete story. But, the microscope results look better than the last time.

Is what I've done to these ceramic hones what may be termed dressing them?
11-28-2010, 07:30 PM
randydance062449

Thanks a bunch for keeping us posted! This is much appreciated.

Yes, you have now "dressed" the hones. You seem to think that the alumina is doing the abrading, I disagree, it is the ceramic + alumina that is doing the abrading. The grit size has now been created by you with the multi directional lapping. The grit size is also much coarser, thats why it cuts so fast. Perhaps, just perhaps, a finer grit would result from dressing with additional directions and/or a finer diamond plate?

Be sure to slightly soften the edges of the hones. It will help prevent microchipping of the razors edge when your honing stroke is slightly off.

I hope others will lend their opinion on this thread......:)
11-28-2010, 10:29 PM
Sticky
I didn't care for my Spydercos' flatness, either. As measured on a sine bar, my UF was the worst of the 3 and was slightly over the allowed tolerance at the time of purchase. I lapped all my Spyderco hones (M, F, & UF) with a DMT 125 XX followed by a 325 X. Mine all cut distinctly different, even though lapped with exactly the same hones and procedures. Lapping is something I routinely prefer because it eliminates some variables and has few-if-any downsides.

Here's a quote from a post made by Sal over at the Spyderco forum, regarding the UF:
- "Our Ultra fine stone took many years to develop and few know about them." - Sal, 01-12-2008
It doesn't take "many years" to figure out how to lap a Fine.

The F and UF have a different density, meaning a different end material; either in component, and/or mix ratio, and/or firing procedure. Test it yourself by tapping each hone in turn, and hear the difference. Their reflectivity is also different.

My UF was purchased several years ago and came with at least a "two-pass" lapping operation on each surface. Not sure about current production. The tolerance for flatness at that time was 0.020". I am assuming they meant "over the entire surface" since "distance over" tolerance wasn't specified. In any event, like your's, they all did better after lapping.

I don't use it much, anymore, as I now prefer several barber hones for speed and feedback. I still like the UF's ability to get a fine edge quite a lot.
11-29-2010, 07:26 AM
PhatMan

Hi,

I was lucky with my Spyderco UF - it was flat enough to be useable for honing razors out of the box. I initially got this stone to act as a low maintenance touch-up stone.

+1 on Randy's observation about the use of slurries on the Spydercos.

I have had good results using a variety of slurry sources (from the cheap King Nagura to coti rubbers, CrOx & diamond sprays) on this stone.

Have fun !

Best regards

Russ
11-29-2010, 08:24 AM
TheMetatron

I'll revive this next weekend after a shave test...

...and, I'll take the advice to round over the edge of at least the ultra-fine ceramic hone. They are quite sharp. Although I haven't caused any chips from them yet, I can see how easy it would be to do.

It was the low maintenance of these hones that I was after when I bought them. However, they have been fiddly to get quite right up until now. I am questioning the wisdom of getting these hones over say, a nice Norton 4/8K. But, I have what I have, and I am motivated to make them work. Just not sure I'd recommend the same path to someone else just starting out honing straight razors.
11-29-2010, 09:12 AM
Bnick

Hones

This may be off the subject a bit but still about hones. I am looking to get into honing my own razor mostly touch ups. I do not want to have to worry about flattening hones and would like to get an as maintenance free hone as possible. Is there any recommendations for this type of hone.
12-05-2010, 12:15 AM
SharpKnife4Life

Quote:

Lapping these hones, to me, is about the surface finish, not the flatness.

Yes, I had the same experience when I lapped my Translucent and Black Arkansas stones. Thety were way too hard for me to get them perfectly flat. The best I could do was to change their surface finish, which did make a difference.
12-05-2010, 12:35 AM
Utopian

Quote:

Originally Posted by Bnick

This may be off the subject a bit but still about hones. I am looking to get into honing my own razor mostly touch ups. I do not want to have to worry about flattening hones and would like to get an as maintenance free hone as possible. Is there any recommendations for this type of hone.

Barber hones tend to be quite hard and so don't require lapping. They work fine for the eternal maintenance of a shave ready razor.
12-06-2010, 04:53 AM
onimaru55

+1 ... The UF becomes very versatile with different slurries.
12-07-2010, 01:16 AM
matt321

I'll just toss in my 2 cents of knowledge here.

My understanding is that the Medium and Fine Spyderco hones are sold straight from the kiln. The Ultrafine is the only one that is surface milled after firing. Thus, the UF is the only one that has visible swirl marks on the surface.
12-08-2010, 05:47 AM
JeffR

Quote:

Originally Posted by richmondesi

Personally, I'm not as big on the mathematically flat concept as others. I think honing is in the hands, and while I'm not going around recommending people don't lap their hones, I don't personally worry much about it.

Unless there is a major unevenness, I don't bother...

I agree wholeheartedly. I haven't found perfect flatness to make any difference. Technique is much more important than the flatness or even the grit rating of a stone.