Diamond vs silicon carbide powder

[Maxlord]

I like to know the difference between lapping between dimond and silicon carbide for a finish on a cermic stone because even tho I tryed the dimond plate method while it worked in making a ultra fine stone,but their is doubt in my mind it a truly ultra fine stone. The powder is 120 or 1200 grit. On unrelated note how many lap on a dimond plate before it considered warned or dull because I lapped the ceramic 7 or 8 times on it already 1000 grit side asking because I want to use the dimond plate just for a finer finish ather the powder for reference it form this video:

 

[kreisler]

I didn't understand a word, so I'm out.
Maybe NORTHWEST_KNIFE_GUY can understand better?

 

[PMQ]

On unrelated note how many lap on a dimond plate before it considered warned or dull

When you "feel" that the diamond plate stop cutting. No one can tell you how many strokes or laps it'll take to fully "dull" a diamond plate, because it depends on how hard you're pressing, or whether you are using any lubricant.

For synthetic stones like Spyderco ceramic stones, or Japanese whetstone, not natural stones, they're made from abrasive particles bonded together. To get consistent results every sharpening, the manufacturer makes sure that all the abrasive particles's size is the same.

Now, you can lap the surface of a 800 grit medium Spyderco stone, and make the abrasives on the surface finer, so you can get a 1000-2000 grit finish. But once that surface layer is ground away, the next layer of abrasives is revealed, you'll return to a 800 grit finish. IMO, this is a waste of stone, that jump of grit in terms of sharpness is not that noticeable.

 

[NORTHWEST_KNIFE_GUY]

I like to know the difference between lapping between dimond and silicon carbide for a finish on a cermic stone because even tho I tryed the dimond plate method while it worked in making a ultra fine stone,but their is doubt in my mind it a truly ultra fine stone. The powder is 120 or 1200 grit. On unrelated note how many lap on a dimond plate before it considered warned or dull because I lapped the ceramic 7 or 8 times on it already 1000 grit side asking because I want to use the dimond plate just for a finer finish ather the powder for reference it form this video:

Ceramic is obviously very hard and so is SIC or silicon carbide (which is also a ceramic) diamond being the hardest of them all, one using three body abrasion and the other using two body. From what I know and someone here please correct me if I am wrong the spyderco ceramic stones all start off around 20 or so micron and the grit in each different stone is determined by a few different factors like how they're fired, type of carriers and also how they're ground. I believe they use a surface grinding wheel "diamond" to finish the UF and that is why it's shows the cutting head marks after a little use. I have tried about everything under the sun and diamond plates for finishing seem to give me the best non glazed finished, abrasives like sand paper seemed to glaze the stone. How to tell it's an UF stones is a little guessing at least on my part however comparing feel, looking at the edge it produces eg scratch pattern under magnification etc. should give one a pretty good idea on the grit of the stone. Also having a stone with the actual grit rating you're trying to duplicate helps.

As far as the plate I guess that would depend on the plates as some are made better than others. On poorly electroplated diamond plates I have seen the diamond just strip off in large patches rather quickly when used with something like sintered ceramic stones, on other diamond plates like ultrasharp it seems to really help break in the plates as they are the most aggressive plates I have ever used. I have used the ultrasharp plates 300-600 on several ceramic stones as well as quite a few other natural quartz and slate stones and are still not what I would consider fully broken in.

 

[HeavyHanded]

Lapping ceramics with silicon carbide is a bad idea for the most part - depends on what you're after.

The SiC will rapidly break down under pressure and polish more than grind/lap. It is also not a lot harder than most fired ceramics, you'll wind up with a plate that can only burnish and has not enough texture left to cleanly remove metal. If that's what you're after, the SiC will work great. For changing the surface texture or significantly flattening an out of spec ceramic, diamond powder will work a lot better.

You can still use SiC but will need to use a fairly coarse grade and refresh it often as you go.

If you're going to use a diamond plate to work ceramics I highly recommend getting some lapidary diamond disks - the bond strength is orders of magnitude better than a diamond plate made for sharpening.

 

[FortyTwoBlades]

Sintered ceramics have an extremely hard bond to them, and a range of mixed grain size (it helps the abrasive grains bond together in sintering if they're not of uniform size) and so they perform very differently from something like sandpaper/diamond plates (a coated abrasive) or a vitrified or resin bonded stone (bonded abrasive) and instead function more like a file does. For lapping purposes 3-body abrasion methods work MUCH better than 2-body, and coarse diamond grit works much more rapidly than SiC due to being less friable and a much larger jump in hardness between the workpiece and abrasive, which results in less blunting of the stone's face grains. You can then finish the surface by either 3-body or 2-body abrasion, again best done with diamond abrasive, to produce different "file cuts" on the face of the stone.

 

[Maxlord]

Sintered ceramics have an extremely hard bond to them, and a range of mixed grain size (it helps the abrasive grains bond together in sintering if they're not of uniform size) and so they perform very differently from something like sandpaper/diamond plates (a coated abrasive) or a vitrified or resin bonded stone (bonded abrasive) and instead function more like a file does. For lapping purposes 3-body abrasion methods work MUCH better than 2-body, and coarse diamond grit works much more rapidly than SiC due to being less friable and a much larger jump in hardness between the workpiece and abrasive, which results in less blunting of the stone's face grains. You can then finish the surface by either 3-body or 2-body abrasion, again best done with diamond abrasive, to produce different "file cuts" on the face of the stone.

Sorry for the late reply but thank you for being as helpful as always,I will be sure to see buy one of your blades