Carbatec Economy Diamond???

[Mr Brush]

I'm due a trip up to Carbatec (Sydney) to pick up some assorted bits and bobs, and was thinking I might also treat myself to a diamond whetstone or two. Application is general sharpening (planes/chisels), but also preparation of scrapers for burnishing.

Now, first thing I noticed was these:

http://www.carbatec.com.au/store/index.php?main_page=index&cPath=270_7420_7497

Carbatec 'Economy' Diamond Whetstones, available in "400 or 1000 grit", 290x62mm, $49 each or $78 the pair.

Does anyone have these (or the smaller versions)??? If so, can I ask whether (a) the grit sizes generally line up with waterstone numbers, and (b) are these Carbatec whetstones flat enough to actually be used for any sharpening???

The alternative is a DMT DuoSharp (I'm thinking the fine/extra fine would suit?), only 203mm size, but costing a whopping $199.

I already have some fine waterstones to finish off the sharpening job (Norton 4000/8000), so seeking advice on whether the Carbatec versions are worth looking at, or should I just bite the bullet and get the DuoSharp??

Any advice much appreciated.

[Marginata]

Hi Mr Brush

We bought the pair of economy diamond wet stones from Carbatec at the school I used to teach at. I too was very interested to see if they were any good. They are excellent for flattening your fine waterstones and working the soles of planes as well as lapping the back of chisels and plane blades. I was very hard on them and was surprised that they did not seem to loose any of their cutting ability.

[derekcohen]

I have a 6" 400 grit. Got it about a year ago to flatten waterstones, but at this length it is too short. Should have got the longer one for that. So I have used it on some small/narrow blades and been pleasantly surprised. It is quite flat (as measured with a Starrett square) and far better than the price suggests. I have no idea what type of diamonds one it, or whether they will last, but so far they are holding up very well. Side-by-side with my DMTs you can see the difference in quality, and I would really only buy the DMT if you are serious about using diamond stones. You know what you getting there.

Regards from Perth

Derek

[Mr Brush]

Thanks for the responses - I knew someone on the forums would have tried these whetstones.

Marginata - your suggestion for flattening waterstones clinches the deal. I'm just wondering, in the case of a fine waterstone which is stored dry (e.g. 4000/8000), is it better to flatten on the diamond plate while the stone is still dry and just blow the loose dust off afterwards with compressed air, or does this work better wetting the stone first (as you would prior to sharpening) and building up a slurry on the diamond? I have the Norton waterstones.

Derek - point taken, and I'll say that if the Carbatec ones are flat enough for you to find useful, they'll certainly do for me. I'll go for the set of the larger diamond whetstones, which means they come in at only $39 each. Even if they prove to be not perfectly flat, the 400 grit one will be useful for rapidly grinding new bevels on plane blades, etc. I assume it is fairly aggressive cutting? I've been playing around changing bevel angles on some Veritas A2 steel plane blades (for bevel up planes), and my 220 grit Norton waterstone cuts fast but literally wears away before your eyes ! A diamond plate for removing the bulk of the material would be a huge improvement, after which I can form a small microbevel using 1200, 4000 then 8000 waterstones. Referring to the DMT stones, what "waterstone equivalent" would you rate their 'fine/extra fine' diamond plates at? I may end up getting one of these later as well, but will give the Carbatec ones a go first.

Thanks again for the responses - I don't know what I'd do without this forum ! :2tsup:

[rsser]

Try international Ebay; there was a guy in the US selling 10" Duosharps for a good price.

Acc. to my Duosharp box Fine = 600 grit, Coarse = 325, Extra fine = 1200

[Mr Brush]

Thanks Ern, I'll take a look on EBay. If there was ever a time to be buying from the US, it would have to be now. Our dollar might even hit US$0.95 at this rate.

Glad I asked about the grits. That makes the DuoSharp 'fine/extra fine' not that different to the Carbatec Economy whetstones in terms of cutting. If thats as far as one can go with diamond whetstones, then the trusty 4000/8000 waterstone will always have a place in the sharpening regime. I'm assuming the only way to get down to the finer finishes with diamond is to use the 'paste on hardwood' approach.

I'd be happy if I could get a nice flat primary bevel quickly and easily on diamond whetstones, then just use my combo Norton 4000/8000 for the microbevel and finish up with a leather strop and Veritas Green Gunk. :D

[Mr Brush]

oooh :oo:......a man in Toronto is offering the 10" x 4" DuoSharp at US$86.97.

Thats about A$95 at current exchange rates (half the local price), but how much can it cost to ship a small item like that to Oz?? That's assuming he does overseas shipments, of course.

[rsser]

Yeah, just saw that.

Grr, makes the 200 I paid at Carbatec grate.

[rsser]

Hmm, 50 USD to post to the UK. Steep but you'd still be well ahead.

Added: or $100 ... http://cgi.ebay.com/DMT-DuoSharp-10-00-in-Double-Sided-Extra-DMW250CXNB_W0QQitemZ220164850012QQihZ012QQcategoryZ66826QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

Ask about shipping. The 50 USD was for expedited international; other services will be cheaper.

[AlexS]

I bought a set of the small ones a few years ago. They weren't much good for sharpening as they weren't really flat, but they're good for dressing the wet grinding wheel.

[derekcohen]

I purchased my 10" DMT Duo on eBay for about $95 USD. Big savings on the local prices even when you add in shipping. You can save even more if you get the 8" stones (about $65).

Regards from Perth

Derek

[kman-oz]

I've been recently converted to diamond plates after seeing thumbsucker's Duostones in action, but couldn't nearly afford the DMT variety, so I've bought the 12" economy 400 grit and 6" economy 1000 grit to try out.

First impressions of the surface are great, they certainly seem to cut very well. The 6" comes in a plastic holder with rubber feet (which don't really stop it moving around on a laminex bench top) and is flat enough for the most discerning diamond user.

The 12" on the other hand is dished very slightly (about 0.3mm clearance when laid upside down on a flat surface). Apparently the bend is isolated to the end with the solid section, the pitted section is dished only 0.05mm along the first 10" of it's length. I looked at a few of the 12" jobbies and they all seemed to have the same problem!?! It's definitely a quality issue because none of the 6" plates (I looked at four) exhibited any such problem. The 6" plates only have a very small solid section so I can't be sure that's a contributing factor or not.

For $25 the 6" stones seems like extremely good value, can't pick fault with it other than the rather useless rubber feet. The 12" at $49 will require the 17mm thick base to be ripped back leaving the steel plate with only a 3mm plastic base, then bonded to some other flat medium. Alternatively you could cut a slot into the plastic underside of the plate with a hack saw to facilitate an easier bend, and then bond it to a flat surface instead.

For mine this isn't a big deal; I'm prepared to spend the time to get it perfect for a saving of ~$80 over on a smaller DMT 8" plate. But if you want it to work out of the box, I'd suggest these aren't the answer you're looking for.

Dave.

[Tex B]

My experience is similar to Kman's. Pretty good, but not exactly flat.

It's very very difficult to get a piece of molded plastic to be consistently and constantly exactly flat, and I suspect that leads to variation between one and the next, and also variation over time to the same one.

Tex

[kman-oz]

Update; I've ripped the original base off leaving a 4.7mm thick plate which I've subsequently lapped flat (+/- 0.05mm across it's length). It seems the mold used for the plastic base is far from perfect because the thickness of the top surface varies from 5.3mm at the ends to 4.7mm in the middle.

I've cut down some 20mm thick acrylic and lapped it flat also, then bonded to two together with Areldite. The result is now flatter than I can fault with either glass or a striaght edge. Took about 2 hours of buggering around, but it was a good excersice in flattening stuff :)

Finially, I took to it with two old Titan chisels with badly rounded backs. Flattening a 1 1/4" took about 4 hours previously using AlOx paper and water stones, while flattening a 1" and a 1/2" took about 30 minutes last night :2tsup:

[J.E. Mike Tobey]

I am a sharpening idiot- but I get good results. I work with pretty darned flat all the time. Even I have practical limits.mt

[rsser]

Thanks for the post K-man.

You may find though that the cut time lengthens as the fresh surface gets knocked down.

[kman-oz]

I did actually. The first 5-10 minutes were *really* fast, and I've abused it for a couple of solid hours with various tools and stones, now it seems to have stabilised. What I find incredible it the shear about of abuse they will take! I can apply about 20kg of force to the back of a 1/4" chisel and not knock out any particles... awesome!