$20 cast iron lap for 1µ diamond

[David Barnett]

Is there any differance between the various diamond pastes? Mono/poli or quality (if that even applicable)

David Weaver gave a good answer so I'll elaborate on price. The range of prices for diamond paste vary widely, from the Norton water-based at 3.79 to 5.59 per gram in a five-gram syringe to DMT Dia-Paste at a whopping 6.95 per gram in a two-gram syringe from woodworking vendors to very cheap from lapidary suppliers. Where some may promote advantages in their more expensive brands, I cannot discern or appreciate any differences that would make a difference to me—not for sharpening woodworking tools. Now I'm not saying the higher prices are unfair, only that branded products are often higher in cost to the vendor than unbranded and perhaps well-known manufacturers are less inclined to offer the economies in recent industrial diamond production abroad.

Because 5 grams of diamond paste will last for a long time, some will certainly amortize and rationalize the cost for the high-priced spread, especially if already placing an order with a woodworking supplier for other items, and while this may get you tighter crystal size grading, slightly higher diamond concentration and purchasing convenience, I've never encountered problems with other vendors offering far cheaper products and I'm fairly demanding as most of my diamond use is for gem faceting, carving and polishing where a single outlier can set one back.

Considering the price difference between woodworking vendors versus lapidary sellers can range from 6.95 per gram down to 80¢ per gram respectively, and even lower direct from Asia with free shipping, I'll avoid the high-end as it really doesn't make a difference for sharpening tools in a woodworking shop. Yes, I will pay more for friable monocrystalline paste and highest-grade polycrystalline paste where needed but not for chisels and planes. If one has deep pockets and were to explore diamonds in the search for the very best edge, I'd suggest the aforementioned polycrystalline to be the most promising place to start.

If you want to know the differences between monocrystalline and polycrystalline diamond, this promotional literature will explain. By the way, the vendor, Pace Technologies, sells both.

[Kees Heiden]

Kees, that's a fair chunk of steel and should work fine for most anything around the shop. If you were doing a lot of hot forging and forming you'd likely want a steel-faced anvil, but for straightening saws and lots of other tasks you only need a tough and fairly flat surface.

Yes I got lucky with that one. When I was collecting some stainless tubing from the local metal-merchant, I saw these chuncks in a corner. In a harbour town, one mans offcuts are another mans sawmaking anvils. I made a couple of saws with folded brass backs using it. First I used the small anvill area of my metalworking vise, but this works a lot better.

[Matthew N. Masail]

Thanks so much David. I guess the bottom line is for a woodworker it does not matter, so I won't worry about it(-: but I very much apriciated the links and info

[Bruce Mack]

Thanks for the information David. I have a granite surface plate. Could I use this with the anvil upside down to flatten the anvil surface, using a series of sandpaper grades? If not, could you suggest an article on how to scrape metal?
Whoops - I looked at the item and realize the upside down feat is impossible.

[David Barnett]

I have a granite surface plate. Could I use this with the anvil upside down to flatten the anvil surface, using a series of sandpaper grades? If not, could you suggest an article on how to scrape metal?

Don't use the surface plate as a lapping surface but to reveal the high spots on the anvil face for scraping as demonstrated in this very old training film. Make a scraper from an old file and buy a tube of prussian blue oil paint, Dykem or equivalent.

Scraping—Why and How, by Ron Gerlach, short article with photographs

The Art of Hand Scraping, by Robert R. Wade

Scraping a wooden block plane, a video. Same idea but on wood instead of iron.

The ultimate manual of scraping: Machine Tool Reconditioning and Applications of Hand Scraping Try libraries

[Steve Voigt]

Don't use the surface plate as a lapping surface but to reveal the high spots on the anvil face for scraping as demonstrated in this very old training film. Make a scraper from an old file and buy a tube of prussian blue oil paint, Dykem or equivalent.

Scraping—Why and How, by Ron Gerlach, short article with photographs

The Art of Hand Scraping, by Robert R. Wade

Scraping a wooden block plane, a video. Same idea but on wood instead of iron.

The ultimate manual of scraping: Machine Tool Reconditioning and Applications of Hand Scraping Try libraries

Those pdfs are great references. I'm sure you'll agree the block plane video is … odd. I think he might as well be lapping. If he used a real surface plate, used a chisel scraper, and didn't wiggle the plane when he imprinted it, he'd have more success.

There was an infill maker a few years ago, Steven ???, I can't remember the last name. Supposedly he scraped a variable "grid" on the soles, such that the "mesh" of the scraping pattern reached its ultimate density right in front of the mouth. Now, that's precision!

[David Barnett]

I'm sure you'll agree the block plane video is … odd.

Odd to say the least. Amusing.

Supposedly he scraped a variable "grid" on the soles, such that the "mesh" of the scraping pattern reached its ultimate density right in front of the mouth. Now, that's precision!

Some machinists developed signature and decorative styles of scraping, frosting and flaking.

Fig-389-Typical.jpg
Frosting(upper) & Flaking(lower)
(short illustrated article and video)

Rivettlathe008.jpg

DSC00279-1.jpg
Basketweave or diaper patterns

4535281329_5b226642c2_z.jpg
Check patterns

220px-Standardcloseup.jpg
And so on.

Most of my bench plane soles are hand scraped and a few machine tools, as well.

[bridger berdel]

Those chinese anvils are covered in a thick paint that just screams toxic outgass if it gets up to anything near heat treat temps.

[bridger berdel]

Odd to say the least. Amusing.



Some machinists developed signature and decorative styles of scraping, frosting and flaking.

Fig-389-Typical.jpg
Frosting(upper) & Flaking(lower)
(short illustrated article and video)

Rivettlathe008.jpg

DSC00279-1.jpg
Basketweave or diaper patterns

4535281329_5b226642c2_z.jpg
Check patterns

220px-Standardcloseup.jpg
And so on.

Most of my bench plane soles are hand scraped and a few machine tools, as well.

Ive been scraping in my planes, too. The tighter pattern at the mouth thing isn't too hard, actually.

[David Barnett]

Ive been scraping in my planes, too. The tighter pattern at the mouth thing isn't too hard, actually.

You're right, progressive scraping becomes intuitive. Not so much bearing surface but I also scraped the frogs and beds on my Stanleys. Actually made a big difference on two planes. One could file them, of course, but scraping's dead accurate and fun. I've scraped my 6" jointer table and fence right down to my little Taig ways and crosslide. Nothing left to scrape now, though, as I don't need more tools. My proclivity really flourished during one long New England winter—cabin fever—because you can only clean your gun so many times.

[David Barnett]

Those chinese anvils are covered in a thick paint that just screams toxic outgass if it gets up to anything near heat treat temps.

Hadn't really thought of that but you're absolutely right. Who knows what's in that stuff. Of course, I melt and cast 45% lead frit but not in closed spaces and without protection.

[Bruce Mack]

Don't use the surface plate as a lapping surface but to reveal the high spots on the anvil face for scraping as demonstrated in this very old training film. Make a scraper from an old file and buy a tube of prussian blue oil paint, Dykem or equivalent.

Scraping—Why and How, by Ron Gerlach, short article with photographs

The Art of Hand Scraping, by Robert R. Wade

Scraping a wooden block plane, a video. Same idea but on wood instead of iron.

The ultimate manual of scraping: Machine Tool Reconditioning and Applications of Hand Scraping Try libraries

Thanks, David.

[Noah Wagener]

I agree, especially on steel tools.



I beef up concentration by making my own stickier paste vehicle and adding more loose diamond.

Diamond paste is convenient for most uses, of course, but I, like you, prefer loose for sharpening and it can be far cheaper.

Do i need to make a paste to use the dry diamonds? They are 100 micron. If so, what should i use?

Someone wrote that these plates go out of flat from use. I thought the diamonds imbed and do not roll around? What is wearing the plate? How can a plate be flattened with diamonds stuck in them?

[Steve Voigt]

Do i need to make a paste to use the dry diamonds? They are 100 micron. If so, what should i use?

Someone wrote that these plates go out of flat from use. I thought the diamonds imbed and do not roll around? What is wearing the plate? How can a plate be flattened with diamonds stuck in them?

Noah, I'm not an expert, but since no one else has answered … the very fine diamonds that are used for honing, say in the 1-10 micron range, will embed pretty well in a mild steel or cast iron plate. Big honkin' 100 micron stones will not embed very well-it would take more pressure than you can apply. So, they will roll around and eventually un-flatten the substrate, though it will take a long time.
If you are interested in using diamond paste for sharpening, as Dave B. was suggesting at the beginning of this thread, you don't need anything coarser than 10 micron. A lot of people who do this only use 1 micron paste--they'll use something like an eze lap "stone" to raise the wire edge, then go to the 1-micron paste for final honing.
On the other hand, if you want to flatten the backs of old irons or chisels, you want to use the loose stones (like your 100 micron ones), not paste, and you want to use them on a Kanaban, or flattening plate, which has grooves cut in it to carry away the swarf. Kanabans were traditionally used with loose SiC, but the diamonds apparently work better.
Of course, you don't have to buy a kanaban; you can use any cast iron or mild steel surface, with or without the grooves. But as with most things, the purpose-built tool works a little nicer.
Joel (tools for working wood) sells kanaban at very reasonable prices.

[David Weaver]

Yes to a fluid with 100 micron diamonds. It doesn't much matter what it is (mineral oil, wd 40, etc).

They do move around on the plate like steve says, and some do embed, but they will wear a plate hollow over time, so it's better to have a thinner plate, like 8x2 or something and consciously keep the blade you're flattening going over the whole thing, including over the edges.

Based on the chart I'm looking at, 100 micron is somewhere around 100 grit. They should work well. I use a 100 grit powder, but that may (or may not?) be a bit too thick.

YOu can true the surface of the kanaban with abrasive paper at some point in the future, but most are pretty gummy stuff (mild steel), and that makes it so cast is probably preferable.

The difference vs. silicon carbide is that with silicon carbide, you can start fast and still get a decent finish and then go to stones, and at one point it was much much cheaper than diamonds. it's still cheaper, but you won't use more than a dollar's worth of diamonds to rework a pitted iron. The diamonds make deep grooves no matter how long you work them, but you can go to any 1000 grit type waterstone without any problems.

Like steve implies, anything in the 100 micron range is never going to be something for bevel work, which is fine. If you ever made the mistake of trying to work the bevel of a tool that has a soft backer (like a vintage US or a japanese tool) on loose diamonds, you won't do it too many times.