Thread: DMT dilemma

Originally Posted by kaptain_zero

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Lots of variables and the reason why I won't flatten my Spyderco hone... I just cannot predict the outcome, so if it works as is, I'm not going to fix it.
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Absolutely. If mine were flat enough, there's no way I'd lap these lil' hard ceramics. As an acid test for the D8C, I'm kinda' glad they came the way they did.

I can say that if lapped, you will still get a noticeably finer finish from the UF (compared to the Fine). No worries on that count.

Originally Posted by kaptain_zero

As for lapping ceramic hones.... it's the surface scratches on the hones that determine the the way a ceramic hone cuts, not the size of the grit it was made from.

Do you mean ceramic hones in general or are you referring specifically to the Syderco ceramic series? The Shapton Diamond on Glass Lapping plate is the cornerstone of the Shapton Ceramic on Glass Series. The Shapton series seem to be very obvious in the care taken to label the different grit sizes on their ceramic plates. I don't understand what you mean.

Chris L

Originally Posted by Chrisl

Do you mean ceramic hones in general or are you referring specifically to the Syderco ceramic series? The Shapton Diamond on Glass Lapping plate is the cornerstone of the Shapton Ceramic on Glass Series. The Shapton series seem to be very obvious in the care taken to label the different grit sizes on their ceramic plates. I don't understand what you mean.

Chris L

Yeah, there is a big difference between Spyderco and Shapton ceramic hones. Spyderco makes solid ceramic hones (the entire hone is solid ceramic). Shapton uses ceramic grit (think crushed Spyderco hones!) with a binder that is intended to allow worn grit to shed, much like manufactured grinding wheels. Spyderco hones won't shed their grit but are meant to work in the same manner as DMT diamond hones... the surface dulls slowly but the pattern ground into the surface during the manufacturing process is what makes them work and should remain so for the life of the hone. Shapton on the other hand developed a type of water stone using ceramic grit in a loose binder or glue if you will. The Shapton hones are designed to shed their grit when it dulls and are meant to be resurfaced/renewed on a regular basis using their diamond reference plate. It's the constantly renewed ceramic grit that makes Shapton stones cut so quickly. Ceramic grit has knife like edges and are almost as hard as diamond but thanks to the softer binder, you can refresh that grit by rubbing off the worn grit using the diamond lap. Hopefully this clears things up.


Regards

Christian

My Fine and Ultra-Fine Spydercos were both lapped with the same DMT D8C coarse plate. This means they should both have the same "surface scratches".
They still put a distinctly different edge on a razor. The Ultra-Fine being finer, as expected.

My understanding is that the two are made of the same binder and abrasive. They may be a different or same ratio binder/abrasive. I have read that they are fired differently. This would certainly explain their very different density.

Test it yourself: put both hones on the same surface and tap them in turn with any implement. You will notice a very different tone. Different tone = different density. Different density of binder/abrasive = different cutting characteristics.

Thanks for you post, Christian. That really helped clarify things for me. And....I can't wait to get my Shapton Diamond on Glass Lapping Plate (not the reference plate) and my Shapton Ceramic on Glass 16,000 grit to start. I'm looking forward to experimenting with the Shapton Ceramic on Glass line.

Chris L

Originally Posted by Sticky

My Fine and Ultra-Fine Spydercos were both lapped with the same DMT D8C coarse plate. This means they should both have the same "surface scratches".
They still put a distinctly different edge on a razor. The Ultra-Fine being finer, as expected.

My understanding is that the two are made of the same binder and abrasive. They may be a different or same ratio binder/abrasive. I have read that they are fired differently. This would certainly explain their very different density.

Test it yourself: put both hones on the same surface and tap them in turn with any implement. You will notice a very different tone. Different tone = different density. Different density of binder/abrasive = different cutting characteristics.

Indeed, the entire manufacturing process will determine the final outcome. That said, lapping these Spyderco hones WILL change the way they cut over what they would have done as delivered from the factory... I'll stand by that.

Chris, as for the nomenclature regarding the glass diamond vs. cast iron reference plate.... they are both reference plates in my view. It is the diamond plate that sets the flatness of the hones and thus my reference to... uhh.... reference plate. Both versions are extremely accurate, far exceeding the requirement of us lowly straight shavers in my humble opinion. The Glass stone Shaptons vs Pro Shaptons is a more interesting issue to me. The Glass Stones are the newest development from Shapton and I suspect in part that it was fueled by the unreasonably high cost of the Pro 30k stone which came to somewhere around $600.00. There were also issues with the Pro Stones being fragile when they were reduced to somewhere around half their original thickness. Placing the ceramic grit on top of a thick piece of glass would allow the use of the grit until worn right down to the glass surface. The end result being, same use, less stone required, which should equal a lower cost hone. I'm just wondering if there has been new improvements in the grit/binder with these new glass stones.


Regards

Kaptain "Inquiring minds want to know" Zero

Originally Posted by kaptain_zero

Indeed, the entire manufacturing process will determine the final outcome. That said, lapping these Spyderco hones WILL change the way they cut over what they would have done as delivered from the factory... I'll stand by that.
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No practical difference.

Originally Posted by kaptain_zero

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As for lapping ceramic hones.... it's the surface scratches on the hones that determine the the way a ceramic hone cuts, not the size of the grit it was made from.

I was addressing this statement, as above. Identical DMT 325 scratches on a F and UF do not equal the same finish from both hones. Unless I misunderstood the analogy.

Originally Posted by Sticky

No practical difference.

I'll be happy to take your word for it.

Originally Posted by Sticky

I was addressing this statement, as above. Identical DMT 325 scratches on a F and UF do not equal the same finish from both hones. Unless I misunderstood the analogy.

I'll bow to this finding as well as I have not lapped my Spyderco. I would expect to find a difference if the two were fired differently.

All I am saying is that Spyderco hones are not designed for lapping.. they are a "use as is" hone. When you modify them, you become responsible for the outcome. When you lap a Shapton, you get a known outcome as the hone was designed to be lapped.

Regards

Christian

With a +/- 0.020 tolerance over the entire surface, some will need lapping for razor use. I'm not the only fella' to find it necessary to do. I haven't heard what the design criteria was re. lapping.

I'll be among the first to say that they are absolutely miserable to lap. While lapping them in my bathroom (water for the DMT), at one point, I actually considered installing a cable-TV connection in there.

Anyone who needs serious lapping done can contact me. I have a very large and fine cast iron lapping plate that can take care of a severely damaged barber's hone in about 45 minutes. This method will definitely get it flat and compounds can be adjusted to give a very fine finish. I would only recommend this for very hard stones.