Thread: Diamond honing plates - is this good thinking

Hi Arron

You can get those plates from Carbtec for $40 each. Or check with Joe Hovel to see if the last of his cast iron has been spoken for:
Cast Iron blocks and Diamond paste for honing (post 27)

Diamond Paste from Ballina:
Lapidary Equipment & Supplies Final Polishing Diamond Compounds & Extenders

I'm not a carver, but I wouldn't think you'd need coarser than 1200 grit, nor finer than 14000. For my flat blades I'm using 1200, 3000, 8000, 140000 followed by a Shapton 12k stone which puts the mirror on (but I reckon you can get away without it). Therefore 2 plates should do it.

Can't help you with the local supplier, but mild steel is fine. Milled flat plates are good. If you try to go any cheaper, the plates often aren't flat. I'm sure the LV plates are flat.

Cast iron if you find some flat somewhere is also good (big debate about this in the recent past on another forum, and the folks doing the experimenting preferred cast).

For fine diamonds you want a fine surface (I think Rob Lee said that the mild steel plates they make have a very fine grind). Whatever you use, the diamonds will wear it slightly hollow in use, something you can slow down by not recharging the plate too often (which avoids lots of loose diamonds rolling around on the surface).

1 or 1/2 micron diamond will feel just as sharp as any of the premium waterstones.

I would only want three surfaces - if you have grit on both sides of the plate and start turning them over back and forth, you'll end up with contamination. If you want graduation of particle size, something like 15,5,0.5 or 15,5,1 (microns) would be a good progression. 15 will be fast cutting, it's similar to an 800 grit stone.

Here is a heads up on diamond plates ...

Look on eBay for the round diamond plates that are designed for compiling to the side of a grinding wheel. These come from China and sell for around $10 or less. They are available in grits from about 150 through 3000. The plates are flat and well made. They are a super bargain of the year. I've bought a bunch.

Regards from Perth

Derek

More in their shop.

Yes, you certainly don't want contamination going up the grits, but going down won't hurt anything (i.e. if the 1200 plate gets a little 3000 on it, it won't matter). I've been using two sides of the plates for ~3 years like so:


then flip the plate to:


The non-slip mat stays in the same relative position by default because I only ever flip the plate. If the plate is removed from the matt then you will need to have the mat marked or remember which was which, but somehow this has never been an issue.

This keeps the cost down (although using three grits only means one more plate), and there is also the issue of availability of cast iron blocks. Joe Hovel has just run out of CI after making 44 blocks. They seem to have become very popular lately.

With the Lee Valley plates i wonder about those machined grooves for two reasons:
1. Are they just paste thieves (does the paste just fill up the grooves and never actually get used?)
2. As the ridges are so narrow, are they prone to being worn down more easily?


A couple of days ago I asked Gemcuts if they could provide the micron sizes of the pastes:
1200 is 15 micron
3k is 7µ
8k is 3µ
14k is 1µ
60k is 0.5µ
100k is 0.25µ

Full chart attached as PDF.

Originally Posted by derekcohen

Here is a heads up on diamond plates ...

Look on eBay for the round diamond plates that are designed for compiling to the side of a grinding wheel. These come from China and sell for around $10 or less. They are available in grits from about 150 through 3000. The plates are flat and well made. They are a super bargain of the year. I've bought a bunch.

Regards from Perth

Derek

You use these as stationary plates to hone on Derek? I bought a lot of them to use on my worksharp and they do a good job there as well. I could imagine making a mandrel to hold a plate and using it in a drill press with the plate being flush in a piece of MDF or similar. A standard style grinding/honing guide could then be used to control the angle. No fuss, no paste, no water except for the final hone.