Cast Iron blocks and Diamond paste for honing

**FenceFurniture** · 18th March 2016, 03:34 PM

There seems to be more interest in this method of honing lately, so I thought I'd post a bit of detail. This is not an invitation for waterstone enthusiasts to point out the errors of my ways!

Just information for those who are interested in Blocks & paste.

What I like about this method is the cheap entry and ongoing cost, the lack of mess, speed of setting up/down, lack of maintenance of the blocks (almost never need flattening), and of course the resulting edge.

I got very sick of this (to be fair, this was after a very long session of flattening and honing)

Waterstones seem to need flattening pretty regularly (I was using Shapton Pro), and whilst that isn't a big job, it's just another thing to keep an eye on.

This is how I set the Cast Iron plates up:

then flip the 1200 to reveal the 3000 side:

then when I'm finished with the 8000, flip it to reveal the 14000:

I'll start with a flat bevel tool steel chisel (as I don't have a grinder just yet). Last weekend this particular chisel had a hollow grind put into it so I have taken it out on a 140 grit Atoma diamond plate, and then finished on the 400 Atoma:

You can see the remnants of the previous bevel at the top. I got tired from the first part, and so left it there, as it's irrelevant.

Then for the sake of this thread I polished the flat bevel up to 14000 on the diamond paste. You can see that the finish is a little cloudy, but this is largely cosmetic

You can see that the remnant bevel is now thinner at the top from the 1200 paste, so it cuts metal pretty readily.

then onto the Shapton Pro 10k waterstone to get the polish that I like:

This highlights one of my biggest hates about waterstones - they never match the bevels from the block, but the blocks all match each other perfectly, so it's pretty obvious which one is out. The Shapton was freshly flattened on a diamond plate.......

This must surely indicate that a waterstone goes out of flat from the very first stroke, technically speaking.

A couple of years ago when I flattened my chisel backs I just gave up trying to do it with waterstones - plenty of steel cut - in all different places.

At this point the edge with no microbevel will cut some hair from my arm, but it was a bit tricky to test as it was still in the jig.

Anyhoo, I took the flat bevel (still in the honing jig), turned the jig up a notch to introduce a microbevel (1°?) and did:
10 strokes on 1200 paste (a stroke is up and back and it was 80-100mm long
5 strokes on 3000,8000 and 14000
5 strokes on the Shapton 10k:

Out of the jig, and the edge is definitely an arm shaver.

So, is it sharp for paring end grain?
Western Red Cedar (left) Pinus Radiata (middle) and Aust Red Cedar (right):

And in detail:

The end grain of the Radiata was impressively smooth to touch.

Just a btw point. When you go from the paste back to a waterstone it's a good idea to clean the grease off the roller if you are using a jig, otherwise you can get a build up a black gunk on the waterstone. It's mainly cosmetic, but I have known it to build up enough to cause interference with the roller, which will cause registration problems.

For the sake of a pic I did not clean the roller this time:

These are the 5ml syringes that I got from Gemcuts in mid 2012 (you do not need the extender fluid - use Camellia Oil, or whatever you have). This pic was taken in Jan 2015, and I have used a further ½ml from the 1200 paste since then:

In other words, the syringes last for years and years. The thing is that you do not need to add paste every time - there are plenty of diamonds embedded on the Cast Iron, and all that is required is a drop of Camellia to charge it up for use again. I do this more often than not.

The bottom line is that for $80 you get two Cast Iron plates (mine are Fully Annealed Grey Cast Iron blocks - FAGCIB), and the paste is $15 per grit. Total of $140 compared to ~$250 or more depending on the brand of waterstone. Then you have the very low mess, quicker set up/down, and an edge that is comparable to one off waterstones.

I didn't take a pic of the mess - there's none to show.

**FenceFurniture** · 18th March 2016, 03:41 PM

You can get Cast Iron blocks here:
Sharpening Get Together (GTG), March 13th, 2016

(send Joe a PM)

**Chrism3** · 18th March 2016, 05:14 PM

Do the blocks go rusty?

**FenceFurniture** · 18th March 2016, 05:16 PM

No - too much Camellia oil on them.

**crowie** · 18th March 2016, 05:20 PM

As per usual Brett, A very thorougher posting, thank you, Cheers, Peter

**DaveTTC** · 18th March 2016, 05:36 PM

Present

Dave TTC
Turning Wood Into Art

**hiroller** · 18th March 2016, 05:55 PM

Nice one Brett.
I note that diamond paste goes up to 100,000 grit.
I assume that the diamond doesn't break down to a smaller grit as much as a water stone which is why you end up with more polish from the 10K waterstone.
If you added another finer diamond grit do you think you would get more polish or is it a limitation of the CI block?

**FenceFurniture** · 18th March 2016, 06:05 PM

Originally Posted by hiroller

If you added another finer diamond grit do you think you would get more polish or is it a limitation of the CI block?

I dare say you would Gavin, and I wouldn't think the CI blocks would limit it - they end up pretty smooth. When Joe's blocks arrive I'll fool around when some Green Honing Compound (which I'll have to get). That might save having to use the Shapton 10k, is my thinking.

**Arron** · 18th March 2016, 06:14 PM

Originally Posted by FenceFurniture

You can get Cast Iron blocks here:
Sharpening Get Together (GTG), March 13th, 2016

(send Joe a PM)

Sorry, but I can't find what you are referring to. Can you clarify where to get them and who Joe is? Google not helping.

Cheers
Arron

**FenceFurniture** · 18th March 2016, 06:18 PM

That should take you to a post by jhovel in another thread. The link is working for me.

In any case if you send him a PM he can fill you in.

**Simplicity** · 18th March 2016, 06:29 PM

Thanks Brett
When are we getting the church up and running [emoji3]

**jhovel** · 18th March 2016, 10:18 PM

This link might be slightly more complete?
Sharpening Get Together (GTG), March 13th, 2016
And I am Joe

I used to be a woody but haven't done much woodwork in the past few years, sort of migrated to the 'other side', restoring vintage metal work machine tools and motorcycles (for which I frequently have to make parts). Occasionally I might do some pattern making (old school woodwork). Actually that's how I learnt most of my woody skills, living with a pattern maker who worked in the research department at Holden... I made a lot of furniture when I got married and built a couple of houses using those skills.
My SIL is a luthier and I enjoy watching him build violins from scratch...
I use the diamond on cast iron sharpening on my own tools - including some of my tungsten carbide tipped metal working tools (e.g. metal sraping tools).
Some time ago I stumbled on a large commercial skillet (about 1m x 0.75m x 12mm thick) an have been cutting that up, milling or shaping the bits flat and surface grinding them smooth and parallel. They are nice and soft, having gone through probably thousands of annealing heat cycles. They impregnate well with diamond and work well for sharpening and lapping. There is a fair bit of the material left so I offered to make some for the guys here....

**Kuffy** · 18th March 2016, 11:00 PM

Originally Posted by FenceFurniture

This highlights one of my biggest hates about waterstones - they never match the bevels from the block, but the blocks all match each other perfectly, so it's pretty obvious which one is out. The Shapton was freshly flattened on a diamond plate.......

This must surely indicate that a waterstone goes out of flat from the very first stroke, technically speaking.

I am getting the same issue with my new Atoma plates and shapton pro 12k waterstone. Personally I think it is the Atoma diamond plates. when flattening the back of a chisel i will point the cutting edge away from me pointing to my right at 45degrees to the plate for many strokes, then rotate the chisel 90degrees so the edge is pointing towards me at 45dgrees to the plate for many strokes, and then hold it perpendicular to the plate to get some witness lines to check my progress. The lines never match up. I believe it is because the thin steel diamond encrusted plate is sticky taped to the aluminium plate. They say the sticky tape 0.0000000000000000000000001mm thick, but i reckon its more like 0.1 and the tape is only about 2inchs wide at each end of the plate, creating a slight valley in the center.

**Arron** · 19th March 2016, 07:40 AM

Thanks Joe. pm sent.

**FenceFurniture** · 19th March 2016, 07:47 AM

My evidence suggests otherwise kuffy. My Atoma plates match the CI blocks every time, and also the large (and useless) DMT plate. When I had the full set of Shaptons none of them matched each other, or anything else.

If you think about it, as soon as a slurry is created that absolutely means the stone is out of flat because material has been removed.

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