Interesting hone test results.

I just got 2 new hones, and was thinking how I could easily judge when each one had done its stuff in a progression. Sometimes I forget or misjudge how coarse the previous hone was, making it hard to tell when all the scratches have been replaced with finer ones. I know, I should pay more attention, but...

I had an idea. All I needed to do was prepare some samples, some bits of steel prepared on each hone, so I could refer to them as needed. I grabbed some steel washers and started honing away. Unfortunately the results were not as straightforward as I'd hoped. :confused:

Instead of a simple sequence of washers with progressively finer scratch marks, I had results that varied in other ways. Ways that I may never have noticed while honing razors, since you don't get to compare results side by side that way.

Here's what I got:

Code:

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Hone            Cutting speed Scratch marks  Shiny? Mirror finish?
Apex (400grit?)  Fast          Clear to eye  Yes    No
DMT 8E (1200)    Medium        Clear to eye  Yes    No
Norton 4K        Fast          Fine          Medium Just about
Norton 8K        Medium        Very fine      Yes    Yes
Coticule+slurry  Fast          Extremely fine Low    No
Coticule+water  Slow          Extremely fine Low    No
Dragon's Tongue  Very fast    Extremely fine Yes    Some

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As you can see, not a simple progression at all. The only true mirror finish was from the Norton 8K. The coticule, although having very fine scratch marks, had an overall matt finish, most unusual (though it makes sense when you think of those rolling garnets in the slurry.) I honestly can't tell from this if the Dragon's Tongue gives a better final finish than the coticule. I only bought the DT because it was so cheap and I heard it was a slow and very fine finisher (around 12K+ level?) I had planned to use it after the coticule, but from these simple tests it might replace it altogether! :eek: Quite a feat from a £10 stone.

Anyway, real-world tests will follow, they will be harder than I thought.

Hope you find these results as interesting as I did.

(Edit> Just to clarify, For the finer hones I did go through a progression before using them. So the cutting speeds refer to how quickly the previous scratch marks were removed, not absolute speed.)

cool, thanks for sharing.


Kristoffer

Interesting that the DT was fast even at the end of the progression. I haven't lapped or used mine yet but this gives me some motivation to do so.

I have coils of 0.15, 0.18, and 0.20 X 3/4 wide tempered blued spring steel. I use this stuff to make springs for tattoo machines. I have thought about cutting some lengths and seeing how quickly the bluing is removed with various grits as well as examining scratch patterns. Maybe someday I will get around to it. :shrug:

Very interesting thread thanks for taking the time and for posting....

I'll have to dig mine out:shrug:
Can we see a wet shot of yours?

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Originally Posted by littlesilverbladefromwale

Can we see a wet shot of yours?

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That really could be hone porn!

One factor to be reckoned with is the variation in the steel being honed. Mainly, hardness and such. The cutting grit may cut deeper grooves in one razor that is soft and shallower grooves in one that is harder. So the test results are useful but not necessarily universaly applicable.

I've also come to suspect that some hones behave differently depending upon what they follow in the progression. So maybe a Spyderco ceramic UF would perform differently following a DMT 8k than when following a Spyderco F.

Here are some pics. Neither hone has been lapped by me. The Dragon's Tongue is a little porous, you should be able to see this in the wet / drying-off pictures.


Dragon's tongue + Coticule - dry:
http://www.g-ray.co.uk/pictures/DTCotDry.JPG
Dragon's Tongue close up dry (white bits are from cloth I used to dry it.):
http://www.g-ray.co.uk/pictures/DTCloseDry.JPG
DT + Cot wet:
http://www.g-ray.co.uk/pictures/DTCotWet.JPG
DT close up wet:
http://www.g-ray.co.uk/pictures/DTCloseWet.JPG
DT drying off:
http://www.g-ray.co.uk/pictures/DTDrying.JPG

Thanx for the review. I was wondering how fast these were compared to the Chinese 12K.
Roughly how many passes for a final polish ??? , depending on steel of course.

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Originally Posted by Rajagra

...
Anyway, real-world tests will follow, they will be harder than I thought.
...

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Real-world tests on surface finish are always hard to quantify, since the results are always a mathematical average .

Even Industry (sometimes locally) can't really agree on a good way to measure surface finish. I have several engineering books on it and the factors (and math) involved can get pretty crazy. Often a dull looking surface will be better finished than a shiny one, and vice versa. Peaks, troughs, repeatability, and profile just barely scratch the surface (pun intended). Rz, Ra, RMS, etc... nowadays electronic signals are analyzed to do the measurements. Here's a wiki link with just a few parameters and formulae. I always liked the German Rz method myself.

I'd be willing to bet that some dull looking finishes will shave better than shiny ones.

Using the larger washers as consistent test slugs is a great idea. :tu

I've got round to lapping my hones with the DMT8C, and I'm kicking myself hard for not getting the D8XX instead. Lapping 6 hone surfaces takes a long time. In fact I had to leave some unfinished corners, which are low, so I can work around them. It took more time because I wanted to be sure to avoid damaging the D8C - I lapped under water and every 20-30 laps I would run a brush over the DMT to remove any trace of slurry.

The lapped Dragon's Tongue looks greatly different. I imagine it will cut a lot slower and give a smoother finish than the original surface. I have left one side rough, it might come in handy.

I have to give another thumbs up to the DT. It is just so perfectly uniform. There are no defects or variances, it's just a big slab of consistent material. It almost seems too perfect to be a natural stone! :D

I've been reading some of the other threads on the coticules/BBWs. The more I learn the more confusing it seems, but it's falling into place. FWIW I did the following progression on 3 razors and it worked very well:
BBW+slurry, diluting down to just water
Coticule+slurry, diluting down to just water
Dragon's Tongue + water
Series of diamond pastes on balsa strops.

From what I've read today, I may have been better off skipping the coticule+slurry stage, and finishing with just coticule+water. But the shave was excellent anyway.

I wouldn't be too concerned about not having the D8XX. It's too coarse to leave a good surface on your other hones, so you would have had to use something finer, like the D8C, anyway.

I think I may just get one of the Dragon's Tongue hones now too.

+1 on the DT Ray. Just had mine 'hand-delivered' today. Superbly cut and I'm looking forward to lapping it and giving it a try (I have to confess that it was a sudden manifestation of HAD as I have no problems at all with my new Shaptons). Ahhhh, is it time for therapy?

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Originally Posted by xChris

I wouldn't be too concerned about not having the D8XX. It's too coarse to leave a good surface on your other hones, so you would have had to use something finer, like the D8C, anyway.

I think I may just get one of the Dragon's Tongue hones now too.

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I'm thinking of getting the D8XX. The rational being that if I do the initial lapping with the XX I won't be risking my D8C wearing prematurely. I can put another pencil grid on the stone and then smooth it out with the C.

Like Rajagra I have also run into stones that have low spots in the corners and I have chosen to leave them and work around them. The pencil grid is still there and I can see the areas I need to avoid. As the stone wears I will eventually lap down to that level. Why take off good honing surface if it isn't necessary.

The XX may work faster. I have a friend who avidly collects hones. He sharpens razors but not often. His thing is lapping. He likes to buy a hone and lap it. Check out the slurry and the surface as it evolves. My least favorite thing in the sport is lapping. If the XX will cut faster it will be worth it to me.

"I grabbed some steel washers and started honing away."

Surface finish mostly depends on its hardness. Hardness of ordinary steel washers is very low. If you use hardened steel washers the results could be different, may be quite opposite. To obtain proper results the experiment should be carried out on the same material the straight razors are made of.

Regards,

Richard

Good point ~ I'd still like to know how quickly these put a final polish on a razor :thinking:

I'm glad everyone is enjoying my Welsh discovery.
I'm going to give the DT a go after my coticule then, just as a final polish before Cro2 on card.

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Originally Posted by onimaru55

Good point ~ I'd still like to know how quickly these put a final polish on a razor :thinking:

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I did a pretty extreme test on a spare razor. Abused it pretty badly on a DMT 8C (325 grit) then a D8E (1200grit) then went straight to the Dragon's Tongue.

After 30 laps the bevel already had a nice polish. After 100 most of the DMT scratches were gone, after 200 nearly all were gone. I continued untill 400 but some deep scratches remained. I wouldn't normally run a razor over the D8C!

Using a normal progression you wouldn't need to use many laps on a DT at all.

(Blade was a Joseph Allen non-xxl)

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Originally Posted by JimmyHAD

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My least favorite thing in the sport is lapping. If the XX will cut faster it will be worth it to me.

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+1 x 10

I have one and it cuts much quicker than the grit rating suggests (XX120 vs. C325). If you've been using a D8C, then the first time you use a D8XX will put a smile on your face real fast.

It's saved me many hours of lapping time on the hard hones. It makes the D8C stage a breeze...

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Originally Posted by Rajagra

I did a pretty extreme test on a spare razor. Abused it pretty badly on a DMT 8C (325 grit) then a D8E (1200grit) then went straight to the Dragon's Tongue.

After 30 laps the bevel already had a nice polish. After 100 most of the DMT scratches were gone, after 200 nearly all were gone. I continued untill 400 but some deep scratches remained. I wouldn't normally run a razor over the D8C!

Using a normal progression you wouldn't need to use many laps on a DT at all.

(Blade was a Joseph Allen non-xxl)

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Thanx for the road test.

Anyone compared one to an Escher yet ???????

Your thought process is good. One of the tools I use in this endeavor is a GAR G-4 Surface Comparator set. It's a tool used as a reference tool for surface finishes. It's used by tool and die makers and others concerned with precision. You can use it to compare surface finishes on metals but metal/stone comparisons would not be as good. The comparator and the reference should be of the same material.

Quote:

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Originally Posted by JimmyHAD

I'm thinking of getting the D8XX. The rational being that if I do the initial lapping with the XX I won't be risking my D8C wearing prematurely. I can put another pencil grid on the stone and then smooth it out with the C.

Like Rajagra I have also run into stones that have low spots in the corners and I have chosen to leave them and work around them. The pencil grid is still there and I can see the areas I need to avoid. As the stone wears I will eventually lap down to that level. Why take off good honing surface if it isn't necessary.

The XX may work faster. I have a friend who avidly collects hones. He sharpens razors but not often. His thing is lapping. He likes to buy a hone and lap it. Check out the slurry and the surface as it evolves. My least favorite thing in the sport is lapping. If the XX will cut faster it will be worth it to me.

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I have them both too, and I would agree that having both speeds up the process (plus saves on wear). My comment was based on Rajagra stating he wished he had only the D8XX instead of the D8C. IMO, having the D8C is better than the D8XX if only one can be owned.

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Originally Posted by xChris

I have them both too, and I would agree that having both speeds up the process (plus saves on wear). My comment was based on Rajagra stating he wished he had only the D8XX instead of the D8C. IMO, having the D8C is better than the D8XX if only one can be owned.

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Maybe I should've used my Norton flattening stone. Of course I'd need to lap that first and ... hold on isn't that where I came in?:rofl2:

Now you guys have had the Dragons Tongue for a while how would you rate do the stone. For example where in your honing progression whould you use the DT? How would you compare it to other stones for finishing? I'm not asking for exact numbers etc just you first hand experiences!

Thanks!
:D

It is a polisher, but one gentleman on here says it cuts very fast !:shrug:

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Originally Posted by littlesilverbladefromwale

It is a polisher, but one gentleman on here says it cuts very fast !:shrug:

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Well it certainly did before it was lapped smooth! And since I am unlikely to lap both sides, I still have the option to use the rough side.

I've only used it once as a finisher and it did a fine job. I'm beginning to wish my razors would go blunt quicker so I can experiment more!

I have no other 12K or higher hones to compare it with (except diamond paste on balsa.)

Quote:

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Originally Posted by JimmyHAD

I'm thinking of getting the D8XX. The rational being that if I do the initial lapping with the XX I won't be risking my D8C wearing prematurely. I can put another pencil grid on the stone and then smooth it out with the C.

Like Rajagra I have also run into stones that have low spots in the corners and I have chosen to leave them and work around them. The pencil grid is still there and I can see the areas I need to avoid. As the stone wears I will eventually lap down to that level. Why take off good honing surface if it isn't necessary.

The XX may work faster. I have a friend who avidly collects hones. He sharpens razors but not often. His thing is lapping. He likes to buy a hone and lap it. Check out the slurry and the surface as it evolves. My least favorite thing in the sport is lapping. If the XX will cut faster it will be worth it to me.

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Me too Jimmy, My D8C is already showing signs of wear from the extensive hone lapping I do. My D8F feels more coarse than the D8C.

Quote:

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Originally Posted by Rajagra

I did a pretty extreme test on a spare razor. Abused it pretty badly on a DMT 8C (325 grit) then a D8E (1200grit) then went straight to the Dragon's Tongue.

After 30 laps the bevel already had a nice polish. After 100 most of the DMT scratches were gone, after 200 nearly all were gone. I continued untill 400 but some deep scratches remained. I wouldn't normally run a razor over the D8C!

Using a normal progression you wouldn't need to use many laps on a DT at all.

(Blade was a Joseph Allen non-xxl)

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Was this using the lapped side of the hone? Curious if there was a big difference between lapped and unlapped speed b/c of your post from today.

I'd be interested in how these compare to a spyderco UF, it'd be nice if I could get one of these cheaper hones instead. Hopefully someone who owns both can compare them at some point.

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Originally Posted by Pete_S

Was this using the lapped side of the hone? Curious if there was a big difference between lapped and unlapped speed b/c of your post from today.

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Ah yes, that was after lapping! So even when smooth, the DT started fairly quickly, converting the rough edge to a quite polished edge in about 30 laps. It did seem to peter out when trying to remove the deep scratches, but they were unnaturally deep because of how I did the test.

So the lapped DT is fast to polish, but slow at bulk removing metal.

I suspect that, like a coticule, it would be very hard to overhone using a DT.

(BTW although I only did one session honing usable razors with the DT, I did do 3 at once, they all shaved well.)