Thread: Considering a switch to Diamond Plates

This thread has gone in a slightly different direction, but, nonetheless, back on the original topic, I spent a bit of time today doing tool maintenance. I reground all of my chisels, block plane blades, spokeshaves, and smoothers and I sharpened them up.

I have to say I am incredibly happy with my new diamond plates. No mess, no soaking, no flattening. I really have achieved all of the things I set out to achieve with the switch.

I made myself a recessed board in which to keep the three plates. I felt a bit bad using Red Cedar for the job, but I guess it had to be used for something...

image1 (14).jpg

I have a 600 and 1200 diamond plate and then a leather strop with Chromium Oxide, which I believe is the equivalent of around 25000 grit or something obscene like that. Before, I was finishing on an 8000 waterstone. The waterstone was able to polish the surfaces to a mirror shine that you could use for dental work if you had to. This one doesn't get quite that same polish anywhere but the very tip, but that's the only part that really matters anyway, and WOW am I able to get them sharp. I don't really ever remember my blades being this sharp off of the waterstones. I think the leather strop has something to do with it (obviously), but I am extremely happy with the sharpness of my blades and I highly endorse Paul Sellars' method. I'll post a link to the video. Hopefully it will help someone else out.

Disclaimer: I hollow grind where he does not, and I also don't make those deliberate, cambering strokes that he makes.

https://www.youtube.com/watch?v=vvTcReENk9g

Cheers,
Luke

Nice one mate! I had the same results when I made the switch.
What brand stones did you end up with?

Originally Posted by Ben Dono

Nice one mate! I had the same results when I made the switch.
What brand stones did you end up with?

DMT Diasharp. Available at Carbatec.

Thanks Luke. I see three plates and the strop but you only mention 600 and 1200 and the strop. What is the third grit size as I'm thinking of following your path. Also, what are the plate widths?
Cheers

Originally Posted by Lappa

Thanks Luke. I see three plates and the strop but you only mention 600 and 1200 and the strop. What is the third grit size as I'm thinking of following your path. Also, what are the plate widths?
Cheers

Sorry, the first plate is a 250 grit (extra coarse). I only make a few strokes on it following grinding to establish the bevel. The 600 and 1200 are "the business" stones.

The plates are 8"x3". I think if you go down to the 6" size they get more narrow, and I wanted to ensure they could sharpen the largest sized plane irons (namely #8).

I already had the x-coarse plate, so it wasn't an integral part of the switch. Paul Sellers doesn't hollow grind his tools. I think he deliberately makes his bevels convex, which goes against just about everything I've ever read, but it obviously made him world famous so there must be something to it. He takes 20-something strokes on the 250grit plate every time he sharpens, which I find extremely excessive. If I did this after hollow grinding then the hollow would be gone or close to it. I hollow grind to within half a mm or so of the edge, then I take maybe 5 strokes on the 250grit and the bevel is well established. If it doesn't traverse the entire edge I take a couple more strokes with finger pressure in the parts that aren't established yet and that usually does it. Then it's maybe ten on the 600 and 20 on the 1200.

In all honesty, if you hollow grind (which works great with these plates), then the 250 stone is probably optional. I had it previously for flattening my waterstones.

Hope that helps,
Luke

We were talking about making and testing some cast iron plates to embed diamond dust (in a grease base) into for very fine honing of tools.
I finally found some 'spare' time to make a couple.
IMAG2744.jpg
I'll send one to Kryn to try out and report here and I'll have a play with the other one. I have some 10micron diamond paste to embed in it.

The reason I made one side with checker grooves is that commercial (metal working) lapping plates are usually done like this. I'm guessing for using carborundum paste. I have some grades of that too to try. However, carborundum doesn't embed in cast iron well. So the grooves are probably to let the spent ones (smashed crystals) run away/wash out. I'm not convinced any more that this pattern is needed for diamond paste, but it might be really useful for flattening stones, where you want the removed grit to go somewhere.... Just guessing though.

These plates are 65x200x8mm and very rigid. they are surface ground on both sides after machining the grooves (on my old Douglas shaper).
We'll report back with experience.

Good work Joe. I think I agree about the grooves. The Diamond paste is very viscous, and so does nut run, therefore will not carry away waste. If anything they may act as a reservoir of fresh paste.

Put it this way - I have no desire for the grooves, and I suspect that they may just be paste hungry......no point putting away a plate with unused paste to dry out.

Ok fencefurniture. I'll make the next couple just plain on both sides (maybe for 2 different grades of diamond paste) and send you one to test. PM me with your address please.

Originally Posted by jhovel

We were talking about making and testing some cast iron plates to embed diamond dust (in a grease base) into for very fine honing of tools.
I finally found some 'spare' time to make a couple.
IMAG2744.jpg
I'll send one to Kryn to try out and report here and I'll have a play with the other one. I have some 10micron diamond paste to embed in it.

The reason I made one side with checker grooves is that commercial (metal working) lapping plates are usually done like this. I'm guessing for using carborundum paste. I have some grades of that too to try. However, carborundum doesn't embed in cast iron well. So the grooves are probably to let the spent ones (smashed crystals) run away/wash out. I'm not convinced any more that this pattern is needed for diamond paste, but it might be really useful for flattening stones, where you want the removed grit to go somewhere.... Just guessing though.

These plates are 65x200x8mm and very rigid. they are surface ground on both sides after machining the grooves (on my old Douglas shaper).
We'll report back with experience.

The grooves are to hold loose grit. I do not see any benefit with paste, which is expected to sink into the surface of the iron.

Regards from Perth

Derek

How does paste get into iron? This seems a bit weird to me. Surely the surface isn't that porous.

Also, one of the reasons I went to CBN wheels rather than diamond is that the diamond simply does not last. It gets vaporised. Why would we use diamond paste and not CBN paste? (if there is such a thing)

With the sharpening itself, why doesn't the plate wear faster than the chisel? Chisel steels are damned hard compared to boring old iron. Why wouldn't it dish and carry on just like a regular stone?

Originally Posted by Evanism

How does paste get into iron? This seems a bit weird to me. Surely the surface isn't that porous. The diamonds embed into the soft cast iron.

Also, one of the reasons I went to CBN wheels rather than diamond is that the diamond simply does not last. Why would we use diamond paste and not CBN paste? (if there is such a thing). CBN paste may come, dunno, but very very little paste is used, and because they diamonds embed in to the CI the block can be "recharged" with a drop or two of camellia oil rather than adding more paste.

With the sharpening itself, why doesn't the plate wear faster than the chisel? Chisel steels are damned hard compared to boring old iron. Why wouldn't it dish and carry on just like a regular stone? Yeah, and eventually the block may need a bit of flattening I guess (not yet for me).

And the idea is to move the blade around on the block (for a narrow blade anyway). With a waterstone a single short session with (particularly) a narrow blade will result in a good dishing. However, with a CI block not only is that effect minimised because of the hardness, it gets even more spread because different width blades subsequently give it a workover well before any noticeable dishing occurs. A compound effect.

It's probably a fair assumption that the block will dish but after a far far longer time than waterstones.

Originally Posted by Evanism

How does paste get into iron? This seems a bit weird to me. Surely the surface isn't that porous.

Also, one of the reasons I went to CBN wheels rather than diamond is that the diamond simply does not last. It gets vaporised. Why would we use diamond paste and not CBN paste? (if there is such a thing)

With the sharpening itself, why doesn't the plate wear faster than the chisel? Chisel steels are damned hard compared to boring old iron. Why wouldn't it dish and carry on just like a regular stone?

The paste does not go into the iron - the diamonds in the paste bed in the iron, because the iron is softer than the diamonds. The paste wipes off. You do not want ANY paste residue left on the cast iron.

There is no such thing as CBN paste, as far as I know.

Diamond will hone any steel, however, it is unsuited to grinding carbon steel as the graphite in the diamonds is absorbed by the iron in the steel. CBN wheels, on the other hand, are not affected this way. It may not be quite as hard as diamond, but it is not affected by the carbon steel. The only requirement for CBN wheels is that the steel is hardened.

When honing on diamond paste, essentially what you have created is a diamond plate. The diamonds sit proud of the cast iron, and the blades never touch - hence do not wear the plate.

This is why the grooves in the plates made are not the correct design for paste. They are better suited to loose grit.

http://www.inthewoodshop.com/Woodwor...ningSetUp.html

Regards from Perth

Derek

A good conversation. I just did a humongous sharpening sesh on 49 nomi/chisels a 4 jap smoothing kanna over the last two days (knee is giving me hell and needed to give it a break).... Re-did everything to 12k on Shaptons.

They are very fast and the final edge is incredible.

If the test does proove successful, how do we get our hands on one of these plates? Is there going to be a forum buy? Jhovel offer them for sale perhaps? I'd DEFINATELY love to give them a test with the finer grits >12k. I'd love to go over 12k, but the 30k Shapton is a bit too exe for me

Thanks for the info on the iron permeability. I still find it a bit hard to believe though.

Originally Posted by Evanism

If the test does proove successful, how do we get our hands on one of these plates?

We already know that plates with paste works. I've been using it for 2-3 years with some other plates that were made for me. I use two plates with a different grit on each side - 1200 & 3000 and 8000 & 14000, You can get paste up to 100k. I use Diamond plates for <1200.

Paste is available here:
http://www.gemcuts.com.au/diamond-compounds-extenders

You don't need the extender - Camellia oil works a treat.

Benefits over waterstones (for me - I know others may disagree):

• Superquick set up
• Not water spillage - what tiny mess there is - easily cleaned up
• Superquick set down
• No flattening of stones
• Cheap entry, cheap ongoing.