Lapping Dragon's Tongue for kitchen use

[MarkinLondon]

Fellow babies,

My understanding is that the Dragon's Tongue from Inigo Jones requires a great deal of lapping for razor use. It arrives rough and must be lapped smooth. Does that mean that if one side is left unpolished, or if it's only lapped flat with a very course wet-dry paper, then I can have a stone with the properties of a dual-grit stone?

I ask because I'd like to fix a beat-up set of kitchen knives. The edges are ragged, with visible bends and serrations from years of misuse. I know that my Coticule is entirely unsuitable for reasons that don't require rehashing, so I'm about to try a Cotcarb that's being loaned to me. The Cotcarb is essentially a 600/4000 stone than can correct the bevel and polish the edge. 600/4000 might be too fine, but I'll find that out in the coming couple of weeks.

Discussions surrounding the DT are interesting, and seem to focus on lapping. It's my understanding that the quality of lapping has a large impact on the speed at which it works. What I'm not sure of (I'm new to this subject, as some of you may know) is whether speed and grit have a relationship that I'm not aware of. If I can lap one side of the DT with course paper, and the other side with very fine paper, can I effectively create a stone with dual-grit properties and then use this stone for kitchen knives? That's the question.

In the event that no one has tried this, then I'd be more than happy to post a review of my findings. I ordered one of those hysterically-named stones from that equally hysterically-named company and it should, hysterically, take an entire month for those Welsh folks (also hysterical) to send it to me. You should know that my girlfriend finds my new fascination with razors and hones hysterical in light of my full beard (that's trimmed only on my neck) and the frequency with which she notices that I need a shave.

[tok]

Fellow babies,
Does that mean that if one side is left unpolished, or if it's only lapped flat with a very course wet-dry paper, then I can have a stone with the properties of a dual-grit stone?
...

No, I don´t think so. When you use the DT, it´ll get flatter while in use. When the 600/4000 is still too fine, buy a cheap no name low grit stone(240,400...) or use the wet-dry-paper directly (there´s a tutorial in the wiki).

Regards

[Scipio]

Mark

I would not recommend the Dragon's Tongue for sharpening knives, neither would I advise it were similar to having the equivalent of 2 different grits should you choose not to lap one of the sides. I have found that lapping my Escher with 600 or 800 as opposed to my DMT 325 does give a better finish, but not like having a finer stone really.

The Dragon's Tongue is a hard slate, said to be very slow and quite fine. Neil Miller has them for sale at www.strop-shop.co.uk .

Bottom line is they are not for knives - some would not even bother with them for razors as there are easier ways of achieving a finer finish.

For knives I would recommend a DMT 325 or 600. The coti carb should be good also, though I have no expeience with carbs, I have with cotis. One of my cotis I reckon would work for knives as it is aggressive; the other no chance as it is purely a finisher.

Edit: Back to your original question - if one side is not lapped smooth, it will not be flat and cause you honing problems. I would never suggest that you use an un lapped hone.

[holli4pirating]

I actually liked my DT for razors. Gave about the same finish as the BBW (something like a 6-8k) but was significantly faster. They only become slow because they load up pretty easily, but a quick rubbing to produce a bit of slurry solves that problem.

I do remember reading posts by at least one member who said that the unlapped side of a DT left a rougher finish, but I do not recall if he said anything about what the cut speed was like. Regardless, if you want to cut faster, it would make more sense to me to lap the hone flat and then raise a light slurry as opposed to using an unlapped hone. The slurry will cut more aggressively, but you'll still have a dead flat hone, and you'll still get the best finish possible after you dilute the slurry and finish with just water.

I don't sharpen knives or know anything about sharpening knives, but I'm still curious what your results are just to learn a bit more about the DT, because it sounds like you'll be trying things I didn't. Do keep us posted.

[MarkinLondon]

I actually liked my DT for razors. Gave about the same finish as the BBW (something like a 6-8k) but was significantly faster. They only become slow because they load up pretty easily, but a quick rubbing to produce a bit of slurry solves that problem.

I do remember reading posts by at least one member who said that the unlapped side of a DT left a rougher finish, but I do not recall if he said anything about what the cut speed was like. Regardless, if you want to cut faster, it would make more sense to me to lap the hone flat and then raise a light slurry as opposed to using an unlapped hone. The slurry will cut more aggressively, but you'll still have a dead flat hone, and you'll still get the best finish possible after you dilute the slurry and finish with just water.

I don't sharpen knives or know anything about sharpening knives, but I'm still curious what your results are just to learn a bit more about the DT, because it sounds like you'll be trying things I didn't. Do keep us posted.

Then posted you shall be kept. I've to enjoy honing, so much so that when I'm asked about sharpening cutlery I'm compelled to thing about it.

Oh, and for clarity, I'm not going to, nor did I intend to, use an unlapped hone. I was simply going to lap them with different grits and explore the difference. If an extra fine stone is fast enough, then logic dictates that it can be used more aggressively. I'd like to find out, and those horrifying kitchen knives look like damn fine test rabbits.

[adrspach]

Ok I have to disagree with those who suggested that you can not get two different finishes from DT after two different lapping grits.
So far went through my hands over 10 Large DTs (larger than Neil sells). As I go often to the Inigo Jones to buy them for my friends and lap them before they get them I have the chance to compare them probably more than most colleagues on this forum. The mentioned member here who noticed the difference is Sparq. He noticed after he had one of the stones from me and in that time I did not lap it in the same grit all around. At present he is using one side and edge for his razors and the others for his knives.
DT is very hard slate and there is only one more type in Wales I know which is even harder but so far not used for hones.
Normaly from new I flatten them on 60 grit otherwise it is too rough and also not anywhere nearly flat. Then I put them on 80 grit (these grits done all dry). Then the razor side progres up to 6-800 wet or higher if I feel like it.
Important part of honing on these stones is to have slurry stone. Not as much for the slurry as for cleaning the hone from swarf as it gets loaded very easily.
As with grit for DT it is especislly true that it is natural stone and therefore you can not say one number. I would say very finely lapped up to 2000 grit between 6-12000.
If you want to use it for getting chips and damage off your knifes I would say it would be tooooooooo slow. Get something more agressive such as DMT or simple carborundum and after all damage is gone you can finish it on DT.
I hope this helps.

[holli4pirating]

As with grit for DT it is especislly true that it is natural stone and therefore you can not say one number. I would say very finely lapped up to 2000 grit between 6-12000.

Naturally, there is no way to know what grit it cuts like for sure - this is totally subjective. That said, I strongly disagree that one of these can give a finish like a 12k hone. I lapped my DT with a DMT 325 and then rubbed it with a Swaty (which is definitely finer than 2000) to remove all the scratches and smooth the surface. After that, it still finished like a BBW.

[niftyshaving]

Fellow babies,

My understanding is that the Dragon's Tongue from Inigo Jones requires a great deal of lapping for razor use. It arrives rough and must be lapped smooth. Does that mean that if one side is left unpolished, or if it's only lapped flat with a very course wet-dry paper, then I can have a stone with the properties of a dual-grit stone?

I ask because I'd like to fix a beat-up set of kitchen knives. The edges are ragged, with visible bends and serrations from years of misuse. I know that my Coticule is entirely unsuitable for reasons that don't require rehashing, so I'm about to try a Cotcarb that's being loaned to me. The Cotcarb is essentially a 600/4000 stone than can correct the bevel and polish the edge. 600/4000 might be too fine, but I'll find that out in the coming couple of weeks.

Discussions surrounding the DT are interesting, and seem to focus on lapping. It's my understanding that the quality of lapping has a large impact on the speed at which it works. What I'm not sure of (I'm new to this subject, as some of you may know) is whether speed and grit have a relationship that I'm not aware of. If I can lap one side of the DT with course paper, and the other side with very fine paper, can I effectively create a stone with dual-grit properties and then use this stone for kitchen knives? That's the question.

In the event that no one has tried this, then I'd be more than happy to post a review of my findings. I ordered one of those hysterically-named stones from that equally hysterically-named company and it should, hysterically, take an entire month for those Welsh folks (also hysterical) to send it to me. You should know that my girlfriend finds my new fascination with razors and hones hysterical in light of my full beard (that's trimmed only on my neck) and the frequency with which she notices that I need a shave.

A fine stone like a DT is not a fix-it-up stone.

As for rough or finer lapping of any fine hone small fine channels
produced by a coarse DMT or the equivalent can channel water,
slurry and swarf in ways that improve the cutting action. Much
the same way that telescope polishing has grooves in their pitch
laps for polishing.

Any fine hone might have its place in the final finishing of
a kitchen knife that is already sharp. I keep a barber hone
in the kitchen and sometimes pull out my Chinese 12k to
finish polish my kitchen knives. I polish to two goals: smooth
the bevel surface and place a sharp micro bevel on the edge.
A hard rock unlike a resin based Norton does not invite a knife
to dig a divot out of the surface so the C12K and the barber
hone work fine for touching up kitchen knives (IMO).

A very good razor hone is difficult to find and unnecessary on most
kitchen knives. If your DT ``finish hones'' razors better than any
other rock you have reserve it for razors.

[adrspach]

Naturally, there is no way to know what grit it cuts like for sure - this is totally subjective. That said, I strongly disagree that one of these can give a finish like a 12k hone. I lapped my DT with a DMT 325 and then rubbed it with a Swaty (which is definitely finer than 2000) to remove all the scratches and smooth the surface. After that, it still finished like a BBW.

My guess woul be that you have one of the lighter coloured DTs. Am I wrong?

[holli4pirating]

You tell me. I thought it was pretty dark.