Diamond paste sharpening

[derekcohen]

I usually hone on waterstones (King 800, 1200 and 8000 or 1.2 microns) but have been experimenting with other methods recently in an attempt to find a quicker and less messy method. One new method involves diamond paste.

Diamond stones have been around for quite a long time. The best make are DMT and their lowest grit, until recently, has been an Extra Fine, which is 1200 grit (14 microns). Just not good enough for plane blades. DMT have now brought out an 8000-equivalent. This should be a terrific stone, with an advantage over waterstones of remaining flat, but early reports of its performance are not encouraging.

Over the past few months I have been using diamond paste. This is available in both oil- and water bases. I obtained oil based pastes on eBay in 40, 10, 1 and .5 microns . I did get a sample of this from McJing about a year ago, but the finest grit they had then was 2.5 micron (equiv to a 5000 waterstones).

This stuff is quite cheap. The ebay purchase was 12 x 5gm syringes (of my choice) for $24. This could last a few years.


http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Diamond%20paste/Diamondpaste2.jpg

To use, I prepared a few hardwood boards (I used offcuts of Jarrah), planed smooth, and smeared a pea-sized amount of paste. Instant diamond stone.

Using hollow ground blades, I went from 40 micron to 10 micron to 1 micron.


http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Diamond%20paste/Diamondpaste1.jpg

I have not yet used the .5 micron paste. Instead I used Veritas green rouge (.5 micron) rubbed on a leather strop. This was followed with a plain leather strop.


http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Diamond%20paste/Diamondpaste3.jpg

Excluding time for the hollow grind, the complete honing sequence probably takes about 2 minutes. The result is a razor sharp edge. Really sharp!

Regards from Perth

Derek

[Wood Borer]

Lynndy will be pleased to have her wash trough back:D

[Rocker]

Derek,

I have always used DMT diamond stones, and avoided waterstones, for the reasons you mentioned. For the final honing I use Veritas honing compound rubbed onto a lightly oiled offcut of MDF. Hopefully Carbatec or Lee Valley will start selling the diamond pastes that you mention soon.

Rocker

[silentC]

I suppose you could use that on plate glass as well? Or do you think it needs to be used on something that will capture the grit rather than allowing it to 'roll' around?

[son_of_bluegras]

I've tried it on plate glass and found the glass scrached which may affect the action on the paste and lead to contamination if you use the same glass for the next grit.

ron

[Dan]

Glass with a plastic sheet on top should work. Like the Veritas lapping kit (http://www.leevalley.com/wood/page.aspx?c=2&p=33017&cat=1,43072). I wonder if Overhead Transparency sheets would be ok?

[derekcohen]

The best surface is a cast iron machinist's lapping plate. These are seriously expensive! :o Not going there unless someone wants to make a donation. :U


http://i13.photobucket.com/albums/a262/Derek50/Sharpening/LAPPINGPLATE1.jpg

A closeup:


http://i13.photobucket.com/albums/a262/Derek50/Sharpening/LAPPINGPLATE2.jpg

On the 40 micron Jarrah block I scored a similar cross hatching. This created ridges so I smoothed the block with a plane leaving fine lines. The paste becomes inbedded in the grooves. So far the Jarrah has not dished. If/when it appears to do so I will just use another piece.

Keep in mind the danger of cross contamination. This will show up as scratches in the steel surface. Wipe everything down carefully, especially if using a honing guide (so far I have mostly done this freehand).

I am waiting on a set of Shapton ceramic waterstones (1000, 5000 and 8000 in the Professional series) and will report on these later.

Back to the diamond paste - I have a 400 grit diamond stone, which is the same micron rating as a 40 grit paste. On the paste I was able to flatten the back of a 3/4" chisel blade very rapidly. It left a scratch pattern much smoother than the 400 stone. This leaves me to consider that the stones may not have as uniform a grit as the paste (but I do remind myself that the 400 stone is not a DMT, just a cheap Chinese copy - although it has been flat and great value-for-money from Carba-tec - I originally got it to flatten waterstones).

Regards from Perth

Derek

[silentC]

What do you call "seriously expensive"? I've been thinking about getting a lapping or surface plate for other metal working activities.

I suppose the other question is what damage the diamond paste would do to the plate? If it wears the blade of a chisel or plane, wouldn't the diamond cutting action wreck the cast iron plate too?

[derekcohen]

SC

They are upwards of $500.

The idea is that the diamonds become enbedded in the cast iron.

Regards from Perth

Derek

[rsser]

FWIW I'm playing with wet and dry for sharpening purposes and a piece of float glass 10mm X 100mm X 800mm was $45. And yes it does scratch when grit goes astray.

This is all novel to me as a bumbling amateur but it was a fun to hone down to 2500 paper and shave the hairs off my forearm. Might be why I'm getting funny looks on the train these days.

[thumbsucker]

Question how suitable would a plate of stress relived and milled flat steel be as a base for the diamond paste?

As it is stress relived it would resist warping, the milling would make it flat enough for the purpose of sharpening, and if I could get the cross hatch cut into it it Or fine drilled depressions into the surface just like the DMT plates it should be little different to a cast iron machinist's lapping plate for far less money.

[Pete2501]

Cheers for the advice. :2tsup:

[prozac]

I'm a retired Marine Engineer. We always did lapping of compressor valves and similar on a thick glass plate, usually round in shape. Yes the glass does "scratch" and takes on a cloudy appearance. A quick wipe over with a cloth and spirits gets rid of all contaminants.

As i am just setting up my shed, and being reminded by this post that I would need to sharpen things I nipped down to my local glazier before xmas. For $20 a bought 2 sheets of 10mm float glass roughly 300mm x 400mm. These had all their edges and corners bevelled for safety. I have siliconed the sheets together (one atop the other) to form a solid plate. I will mount this surface plate into a light frame with a ply lid to protect it from damage.

If you find that your grinding paste dries out in use it is a simple matter of adding a few drops of light oil as you lap to return it to a paste.

Lapping can be very therapeutic.

prozac

[thumbsucker]

I took one of my spare 50 x 100 x 8 mm blade from D2 batch 01 which does not have a bevel ground on it and rubbed some Veritas rouge on one side to use it as a makeshift machinist's lapping plate. I am glad to say that it works much better then any wood or leather stropping surface I have used, you can put a fair amount of down pressure without risking a dig in. The Veritas rouge did drift around allot and I thing the grid lines would be very helpful to catch the Veritas rouge or diamond paste.

I may just have to have a few of these made up for me in a larger size.

[kman-oz]

Derek, if you're having good success with these on Jarrah, is there any reason you couldn't use MDF? I've been using the Veritas green honing compound on MDF with great success and it occurs to me that an oil based paste might work equally well. It's certainly a cheap alternative to a series of 12 diamond plates!

[derekcohen]

MDF is not recommended for diamond paste. It tends to be absorbed too much into the MDF. You want it to sit on the surface. I find that a hard wood, like a scrap of Jarrah (planed flat), works very well.

Regards from Perth

Derek

[kman-oz]

In that case, would a harder/oilier timber like Spotted Gum be better?

[derekcohen]

I am sure that spotted gum will work well. Make sure you plane it flat first.

WARNING: be careful about using honing guides with wheels on hardwood/diamond paste. The wood gets quite slick, and the wheels do not turn easily .... you can end of honing a flat spot on the wheel. DAMHIK!

Regards from Perth

Derek

[kman-oz]

I'll be sure to get it flat :) As soon as my diamond paste arrives I'll be sure to report.

I've been practicing honing freehand, so my intention is to freehand only on the diamond paste. I'll be using it primarily for flattening backs and establishing an edge off the high-speed grinder. I'm still not confident grinding right to the edge with O1 tool steel (unlike D2 which tends to be more hardy) and thus far I've found it simpler to get a nice hollow grind then establish the actual edge with stones. Of cousre, this can be slow, hence the diamond experiment.

Thanks for your help!

[J.E. Mike Tobey]

Though I am quite far away, I will have quite nice purpleheart 8" diameter, 2" wide wheels with 11mm centerhole(Tormek axle). A while back I experimented with diamond paste on an American Maple wheel placed along side the leather covered wheel. It really put a finished edge on whatever got near it. They are Made and Sold by "New Traditions Tools and Finish-JET"- not practical to send to you mates but believe me, they do the job well.mt

[kman-oz]

I received my diamond paste this afternoon, from 40um micro all the way down to 500nm. I'll post back tomorrow with findings on both Jarah and Spotted Gum.

[simon_b]

kman
Where did you get your diamond paste from?
Sounds like something worth trying!

[kman-oz]

G'day Simon :) I'm guessing this is the same stuff Derek purchased from eBay. This (http://cgi.ebay.com.au/DIAMOND-PASTE-OR-LAPPING-SET_W0QQitemZ230215342318QQihZ013QQcategoryZ105830QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) one goes off on Saturday evening, mine was less than $20 including postage from the same seller.

Ok, so this stuff, right, it's like this miracle paste in 12 colours.... GET SOME!

Like Derek, I started with some 40um on hardwood, and I'm blown away with how well this stuff works. A half-a-pea size squirt of paste onto the edge of a scrap Jarah board, spread it nicely with a chisel back and hone away. Not only did the 40um chew a reasonable amount of material away in a short time, but once it's embedded itself into the surface of the timber it apparently breaks up into finer particles making the polish finer as you go. When it seems like it's not really working any more, a quick squirt of RP7 (WD40) and it's back to cutting fast again!

By the third squirt of lubricant it's basically done, but you then require only a very small addition of paste to the existing board to get cutting again. I expected that half of the reason it stops cutting it because the surface gets clogged with steel particles, but it prooves difficult to clean the surface without loosening the diamond grits also.... considering the amount of paste used I consider this a non-issue.

I went straight from the 40um to the 10um and had a level of polish within 10 seconds. Another 10 seconds and it's ready for the next grit! 3.5um, 1.5um, and I've never seen a finish like this before. Even the Veritas green rouge isn't this good, but I'll get to that later.

Now, this is the bit where Derek and I will disagree; I tried four different grits on five different timbers and found distinctly different results with each. However, on one point I must agree with Derek, any timber surface must be *planes* flat, not lapped on abrasive paper. This is critical to success.

Results are as follows: softwoods/MDF are best for coarse grits, while hardwoods are best for fine grits. My feeling is that the coarser grits tend to roll around on the hard timbers and not do a whole lot of work, while on MDF they tended to press into the surface and stay there, apparently producing a mock coarse diamond lapping plate. Interestingly, after initial application the coarse grits required a little time to settle before really doing any work (perhaps 10-15 strokes on the back of a chisel). By the same reasoning it appears that the finer grits tended to disappear into the surface of softwoods and do nothing, while on hard woods they smoothed out very quickly after application and started working immediately.

Now, back to the Veritas green rouge problem. I have found that the 1.5um diamond paste produced a far superior finish. When you consider the paticle size rating, this doesn't make any sense, but it appears that my honing process was flawed. I tried the 0.5um diamond paste on some MDF along side the rouge and found that neither produced the finish of the 1.5um paste on hardwood.... the penny drops :doh:

Lesson learned, never hone on MDF ever again! I took the chisel honed on the 1.5um hardwood scrap straight to a peice of fresh MDF with nothing on it, and you guessed it, it was scratched to buggery in three seconds. I can only guess this is the fault of the glue used to make the stuff, needless to say I'll be planing a few Tassie Oak boards down for honing surfaces this weekend :)

Dave.

[scooter]

Informative post, Dave, thanks. :)

[Groggy]

Dave, have you tried the paste on a soft metal plate or granite?

[BobL]

Dave,

How do you know that all that is being obtained is just a shiny surface as opposed to making a flatter surface?

The reason the 0.5 micron is not having any effect is it may be falling in between the wood fibres and not able to get near the metal.

Cheers

[derekcohen]

I am still using Jarrah offcuts. They have served me very well. However, I am going to make up a series of metal plates out of either an old saw or scraper blades. I have a feeling that the latter is the way to go.

Regards from Perth

Derek

[kman-oz]

Greg, I had only limited time yesterday to try these out, but I have some malamine to try, some mild steel plate and some cast iron also. My feeling is that only the finer grits will work on these, but I'll try them out anyway.

Bob, I was given an interesting method for checking this some years ago; hold the peice in a vice and using a light source as close to a point source as possible (I've got a low voltage Halogen lamp that works pretty well), cast a reflection of your finished surface onto a dark wall. Any surface imperfections will show up readily, and the dimensions of the reflection can be used to determine whether the surface is flat or not. I like a 1:5 ratio; 1 foot from light source to work peice, 5 feet from work peice to dark wall, which is effectively 5x magnification of the peice.

I'm yet to successfully try the 0.5 on anything yet, as soon as I do I'll report back. The only medium I'd tried was MDF in discovering the flaw there, I have some Spotted Gum and Iron Bark to try also.

Derek, thumbsucker was saying he's had success using one of the D2 blades as a medium for honing with rouge, perhaps the harder steel is a better medium? Time will tell.

[BobL]

Guys,

Now that Derek, Dave (Dozy, Beaky, Mick and Tich - that's my pathetic attempt at an on 60's reference) have opened the pandora box on the Diamond paste are we all going to jump on epay and bid against each other for the next few months. How about we form a co-op and approach the ebay seller and see if he will do us a bulk deal?

Just a thought?

Dave, RE: Testing: Do you mean the size of the reflection produced?

[jmk89]

Guys,

Now that Derek, Dave (Dozy, Beaky, Mick and Tich - that's my pathetic attempt at an on 60's reference) have opened the pandora box on the Diamond paste are we all going to jump on epay and bid against each other for the next few months. How about we form a co-op and approach the ebay seller and see if he will do us a bulk deal?

Just a thought?

Dave, RE: Testing: Do you mean the size of the reflection produced?

Bob

McJing (http://www.mcjing.com.au/engineering/toolframe.htm) sell the diamond paste at $6.00 per tube (look under Engineering, Diamond Tools). I have used it (planed spotted gum as the plate) and it's as good as the Hong Kong stuff and you can buy a whole lot of other useful stuff from McJing at the same time!

Cheers

Jeremy

[BobL]

McJing (http://www.mcjing.com.au/engineering/toolframe.htm) sell the diamond paste at $6.00 per tube (look under Engineering, Diamond Tools). I have used it (planed spotted gum as the plate) and it's as good as the Hong Kong stuff and you can buy a whole lot of other useful stuff from McJing at the same time!
y

Thanks JK - I try to avoid opening the McJing site cos I often end up finding some new gizmo!

Is their 4000 grit fine enough?

[kman-oz]

Dave, RE: Testing: Do you mean the size of the reflection produced?

Actually the word I was looking for was 'projection' rather than 'reflection', but you get the idea :)

[jmk89]

Thanks JK - I try to avoid opening the McJing site cos I often end up finding some new gizmo!

Is their 4000 grit fine enough?

Seems fine enough for me, but those who are greater prefectionists may disagree!!!:D

[kman-oz]

Now that Derek, Dave (Dozy, Beaky, Mick and Tich - that's my pathetic attempt at an on 60's reference) have opened the pandora box on the Diamond paste are we all going to jump on epay and bid against each other for the next few months. How about we form a co-op and approach the ebay seller and see if he will do us a bulk deal?

This (http://cgi.ebay.com.au/12-pcs-5gram-Diamond-polishing-lapping-paste-compound_W0QQitemZ260205078978QQihZ016QQcategoryZ105778QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) seller always has plenty, I'm sure a bulk order would be favourable.

[thumbsucker]

I would put my name down on a bulk order, but I am not volunteering to organize it.

I could imagine a sharpening station with 5 steel plates each with a different paste, like the machinist's lapping plate.

5.0 Micron - Fine Polish (Blue)
2.5 Micron - Mirror finish (Pink)
1.5 Micron - Mirror finish (Dark yellow)
1.0 Micron - Mirror finish (Light yellow)
0.5 Micron - Final Polish (Rose)

The guys in Hong Kong say "Please let us know if you are looking for any combination." I would not need the coarser grits so I would only take the 7.0 to 0.5 micron syringes or get twice as many of them.

[derekcohen]

You do not need all those grits. I go 40 - 10 - 1 - 0.5 microns for a full grind, and omit the 40 when re-sharpening (unless the bevel is quite rounded).

Regards from Perth

Derek

[BobL]

I would put my name down on a bulk order,

I could imagine a sharpening station with 5 or 6 mild or stainless steel plates each with a different paste.

7.0 Micron - Pre Polish, fine lapping (Purple)
5.0 Micron - Fine Polish (Blue)
2.5 Micron - Mirror finish (Pink)
1.5 Micron - Mirror finish (Dark yellow)
1.0 Micron - Mirror finish (Light yellow)
0.5 Micron - Final Polish (Rose)

This morning I was talking to a guy at work who polishes small rock samples that have to be analysed under special analytical equipment so they have to be super smooth. He uses using silicon carbide and diamond pastes and discs and has been doing this for 20+ years, so he has heaps of experience. I asked him about the sequence of grits he uses for polishing and he reckons that all you need to use is an approximate halving sequence (so 7, 2.5, 1.0) so you can probably get away with 3 plates instead of 6. The thing is these pastes always contain a mix of grains to start with and tend to break up as you use them so after a while the grains are fairly small.

He also gave me some 180 and 600 grit Silicon Carbide which he says to sprinkle these on a wet mild steel plate that has been flattened on wet and dry on a glass plate substrate. Here's (http://www.hocktools.com/sharpen2.htm) is a neat little how too on how to do this. I will try this out in the next few days.

[thumbsucker]

Thanks for the link and info, it looks like some mild steel will do fine. I think I just get 5.0, 2.5, 0.5, grits since I have the DMT diamond plates that stop at 9 micron.

I made some enquires about mild steel, the stuff is dirt cheap and soft for a piece 100 x 15 x 200 mm which would be a huge plate its only $8, lapping it with some wet and dry would flatten it up quickly.

Would scrap metal merchants sell nice flat mild steel?

I gather you would not want anything to smooth so as to catch diamonds and slurry?

[kman-oz]

This morning I was talking to a guy at work who polishes small rock samples .... He also gave me some 180 and 600 grit Silicon Carbide...

Would you mind finding out for us where this stuff is readily availabe?

[jmk89]

Would you mind finding out for us where this stuff is readily availabe?
Jewellers' supplies is where to look.

[thumbsucker]

Would you mind finding out for us where this stuff is readily availabe?

Try Dazlyn Gems (03) 9583 1998 Shop 26 Thrift Park Shopping Centre 16 Lr Dandenong Rd Mentone VIC 3194 AUS - I bought bags of 0.5 micron Aluminum Oxide from him. Very Good service.


Called and and they sell Silicon Carbide in 500 gm bag from 46 grit to 1200 grit

1200 grit == $18.50
0600 grit == $15
0220 grit == $5

[munruben]

Would you mind finding out for us where this stuff is readily availabe?Carba-tec sell a Veritas Lapping Kit (page 81 of the 2007 Carba-Tec catalogue) for $33.00. kit includes five X 2oz containers of Grit Silicon Carbide of 90x 180x 280x 400x and 600x and some instructions.

I don't know if they sell the grit separately but this seems a good range in the kit.

[thumbsucker]

I emailed the guys from Hong Kong. Asking about a bulk order here is what I got back:



Thank you for your question. sorry that because of my poor english, I'm not sure your meaning. Do you means you are looking for bulk order for those lapping pastes in specific micron? Yes, we did looking for dealer about that. We can offer US$1.80 per piece with shipping if you order over 100 pieces at once, any micron.

Please let me know if I misunderstand your meaning. Thanks

Teddy
THK Diamond Tools


$29.99 + $10 shipping = $39.99 / 12 Syringes == $3.3325 per Syringe

With the discount it is a saving of per Syringe $1.2943402243 == $3.3325 - AU $2.0381597757 per syringe if a bulk order of 100 or more are ordered.

All we would need is 8.3 people to order each a full set of 12 to get the discount. However reposting inside OZ at $10 average would eat away the margin. (12 syringes x $2.0381597757 per syringes) + $10 re-postage equals = $34.4579173084, for a glorious saving of $5.5320826916.

I am hard up for cash, but that is not worth it. However still bloody cheap, for what you get. But not worth it. However someone like McJing are making a killing selling the diamond paste at $6.00 per tube.

[dsb1829]

Hey Derek, it has been a year now. Did this method fall by the wayside entirely or do you still find use for it?

I just picked up some of the same paste, or it looks the same and also from e-bay. I wanted to try it as a post-black Arkansas/pre-leather strop on a hardwood block.

[derekcohen]

Diamond paste is still on the menu. It is an alternative.

My most recent sharpening article does involve it ..

http://www.inthewoodshop.com/WoodworkTechniques/Stroppingwithgreenrougeversesdiamondpaste.html

Regards from Perth

Derek

[Heavansabove]

I have not started on diamond paste yet. I do have a small cast iron surface plate and some coarser diamond paste, but plan to get some fine paste and only use that. There has been quite a bit of fora traffic flow over the last year about the problem of avoiding contamination by coarser grits as you get finer and finer. Apparently almost impossible to wipe off all the diamond when you finish at a particular grit.

A solution proposed was to use diamond paste only as the last step (microbevel). Another suggestion was to interpose another medium as the penultimate step, say a waterstone, to dislodge any diamonds from the previous stage. More broadly to use diamond paste every second step, finishing up with diamond paste either on a plate or strop.

Then again, I have not actually done it yet. By the way, a good source of silicon carbide (SWMBO was into it) is lapidary suppliers/clubs.

cheers
Peter

[dsb1829]

Derek, I had caught that posting. Between that and some information cedarslayer posted over on woodnet I decided to pick up some paste to play around with. I am debating on substrates at the moment. I can get mild steel off ebay or mcmaster carr since I am stateside, but I have my doubts about them staying flat for any amount of time. Wood and leather substrates are also up for consideration. I think the finer grits, sub 5u, are going to be a good match for a wood substrate so I don't dub edges or make too much of a mess.

At this point I am heavily into experimenting. Each method has pros/cons. I think I am of a similar mindset to yourself, just looking for the best shortcut in sharpening. One of these days I am going to lay everything out and post my shameful collection of sharpening media :)

[Doug Hobkirk]

Several entries mentioned they were going to try various metal substrates including old saw blades. Have any of you tried it yet?

[Jack E]

Derek,
Could you supply some details about your strop?
Where did you get the leather?
Is it glued to MDF and what type of glue?
Do you use Veritas green rouge on it?
Is it hard or supple?

Cheers, Jack

[derekcohen]

Jack

It is from Tools for Working Wood ...

http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=PROD&Store_Code=toolshop&Product_Code=MS-HORSEST&Category_Code=

I used 3M contact glue to attch it to hardwood.

Details of honing are here:

http://www.inthewoodshop.com/WoodworkTechniques/Stroppingwithgreenrougeversesdiamondpaste.html

Regards from Perth

Derek

[Jack E]

Thanks Derek.

[steveo_mcg]

For the guys who have tried this, did you find a metal substrate better than ply? Any one know how well beech would work, its quite cheap at the local hardwood place.

My package of pastes has just arrived from honkers but i'll have to wait till the weekend to try it out.

[steveo_mcg]

We'll i've had a chance to try them and for honing and polishing the cut on the end of my finger where i was wiping the 0.5 paste from the chisel blade seems to suggest it works great, confirmed that by easily cutting the end grain on some pine.

But it never seems to get a (noticeable) wire edge on the back with the 14 micron with my 1k waterstone this appears very quickly especially on the microbevel. Is this normal?

[kman-oz]

G'day steveo,

Regarding metal substrates, I found an aluminium plate to work very well with the finer grits ( <10 micron) which is all I really use now. The steel that I'd tried seems to do some damage to the edge if you weren't really careful, the aluminium far less so.

As for the wire edge business, my experience suggested that the diamond pastes would break down further as you went, making for a finer grit the longer you honed. Because they can remove material fairly quickly, it's possible you're producing and then removing the wire edge before you've even seen it. Impossible to say with any certainty without seeing your process.

What stone are you using and what medium for the paste? It may also be an imperfect honing medium rounding the edge slightly and removing the wire edge prematurely.