HELP!!! (With Grits)

D

Dieselashi

Joined
Feb 12, 2010
Messages
98
Good morning (for me, anyhow) everyone!

Adjusting the bevel on my Izula last night took forever on my SharpMaker with brown/medium stones. I would like to purchase some sandpaper to use in conjunction with the Spyderco ceramics to speed up re-profiling at one end and to add a bit more polish at the other.

I've been scratching my head at the "Grand Unified Grit Chart" and have a pretty good idea that what I want are FEPA-F grades 360/600/1200 (@ 23/10/3 micron particle sizes) to complement my stones. Looking at vendors I don't see any consistent labeling scheme for grits. I am loathe to pay more in shipping than the paper is worth from an internet dealer, I was going to go to an automotive store but I am confused what particle sizes the grits they stock are. Can anyone help?

For example, "3M Imperial Wetordry automotive sandpaper" is quoted as "600-grit" and/or "P600-grade"... this would lead me to believe it is FEPA-P 600 about 26 microns? Are these sheets, for those with experience, accurately graded? It appears like the FEPA-P grade doesn't go below 5 microns at P5000, and the highest I can find at a well-known automotive chain looks like P2000 @ 10 microns, which is barely finer than the white SharpMaker stones.

I guess the question is where to find FEPA-F graded abrasives for a reasonable price? Does anyone have another, equally economical suggestion for augmenting the SharpMaker's re-profiling abilities? Supplier for 3m wetordry polishing paper (color-coded, micron-graded stuff?)

Knives involved are an Izula (1095), Mora (12c27), SAK (?), Para-Military (s30v) and Moki (vg10)...

Thank you!
 
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I would recommend 3M wet/dry paper, used with a bit of water. It's available at most hardware outlets in the very course grits, and in automotive supply stores up to at least 2500 grit. It may be available finer than 2500, but I've not seen it.
 
Thanks, Ben. I had the idea that I would go and browse a hardware or automotive store this afternoon, but my question is mainly about how the 3M Wetordry product is actually graded in terms of particle size (microns). An arbitrary grit number assigned by the manufacturer is fine for relative levels of finish, but not to compare specific sizes between different media (sandpaper and ceramic, in my case). When they say "600-grit", is is it FEPA-A, FEPA-P, CAMI... I don't know, and they are all different sizes even if the numbers are similar. Can anyone shed some more light on this?
 
After I ran into that same problem myself, I actually called up 3M and asked. They told me that it might be EITHER, and if it was graded as "-P" paper, it was in the FEPA scale. If not, it was ANSI.

I wouldn't worry all that much about it, I'd grab one of the 3M packs (they come in third-sheets for palm sanders) of whichever grading scale they have handy in 400, 600 and 800 grit, both scales will work JUST fine for your purposes. :)
 
Particle size is almost meaningless, when trying to compare one type of abrasive (ceramic/aluminum oxide, silicon carbide, diamond, chromium oxide) against another type. The size only matters when comparing finishes using varying grits of a single type, like only diamond, only SiC, only AlOx, etc. They each cut very differently, due to differences in hardness, shape and how particles fracture or break down with use. An example, comparing ceramic to sandpaper (silicon carbide wet/dry), is how a '600' grit ceramic, in the ballpark of a medium Spyderco, will leave a much finer finish than a '600' grit sandpaper. Komitadjie's chart shows that the 'medium' Spyderco more closely compares to ~1200 wet/dry paper (seems about right to me; I've used both quite a lot).

With Spyderco's ceramic, in particular, they use the exact same grit for each of their medium, fine, and UF hones. The only difference is in the process they use to surface-finish each one. Many of us have figured that out the hard way (myself included), by attempting to lap/flatten them using diamond or other means. I have a (formerly) medium/fine Spyderco DoubleStuff hone, which I flattened on both sides, using a Coarse DMT Duo-Sharp bench hone. I now have a 'new' hone, which seems to be 'Ultra-fine' or better on both sides (can't tell the difference).
 
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Obsessed with Edges said:
With Spyderco's ceramic, in particular, they use the exact same grit for each of their medium, fine, an UF hones. The only difference is in the process they use to surface-finish each one. Many of us have figured that out the hard way (myself included), by attempting to lap/flatten them using diamond or other means. I have a (formerly) medium/fine Spyderco DoubleStuff hone, which I flattened on both sides, using a Coarse DMT Duo-Sharp bench hone. I now have a 'new' hone, which seems to be 'Ultra-fine' or better on both sides (can't tell the difference).
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that's good to know. i thought this was only true for the F and UF. i guess the color fooled me i was sure the M had a different formulation.
 
pwet said:
that's good to know. i thought this was only true for the F and UF. i guess the color fooled me i was sure the M had a different formulation.
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The medium may have a different binder of some kind, or some other secondary ingredient accounting for the color difference. I'll have to dig around a bit, to see if I can find how Sal Glesser described the differences between them.

Found these quotes from Sal Glesser on Spyderco's own forum (link to a VERY ENLIGHTENING thread there, below):
"All of the ceramics use the same micron size (15-25). the different grits are created by different carriers, different firing techniques and diamond surface grinding.

sal"
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"We've spent a great deal of time trying to determine grits for our stones. The manufacturer has also worked with us, to no avail. A guess seems to be best.

Most abrasives are measured by the grit size used in the matrix. Our ceramic doesn 't work that way. Grit size is constant.

We've tried to compare scratch patterns as Cliff mentioned and this is probably the closest, but nothing that we can say "This is blah blah". Then the Japanese water stones jump into the equation and suddenly there is whole new set of numbers.

So where we end up is:

Our diamonds are a 400 mesh (measureable). (600 on the Duckfoot)

Our gray stone is "medium". (Same material as fine but different carriers and heat treat).

Our fine stone is fine.

Our extra fine is a surface ground fine.



sal"
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http://www.spyderco.com/forums/showthread.php?p=395257#post395257
 
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FEPA-P is for coated abrasives like sandpaper, FEPA-F is for stones. The abrasives are not graded arbitrarily, we just have to find out which scale is used.

You can compare abrasives by particle size as long as you also understand that they have different shapes and binders. Natural stones are like ceramics in that density and surface finish affects level of polish, not merely particle size. Using them with a slurry vs with clean water can have a massive effect on edge finish, of course you don't get a slurry from a Spyderco stone.
 
Wow, more information than I was prepared for, you guys really know your stuff! Understanding that I would like to add coarser and finer levels to my sharpening routine, what type/grit sandpaper would be appropriate to use? Perhaps that is a simpler and more practical question for those of you with (clearly) more experience than me.

Thanks!
 
I've purchased wet/dry sandpaper in 220/320/400/600/800/1000/1200/1500/2000 grit. Unless I'm trying to completely re-shape the bevel on a big blade, I generally don't use grit below 400. I usually take advantage of the full progression above that, however, as I like to polish the edge/blade as highly as the sandpaper can make it. Not essential, but it's just a preference issue. If I wasn't needing or wanting a high polish, I think I could do just about everything with maybe 400 for establishing a bevel, then 600 (or 800), and 1000 & 2000 after that. The 1000/2000 grits are very handy, when stropping isn't quite enough to restore a really sharp edge. I just 'strop' on the high grit sandpaper, on hard/firm backing, for a few passes (maybe 10-20 per side, or less). Then strop on balsa, leather or hardwood after that, with either diamond, Simichrome polish, green compound and occasionally red compound (rouge). The choice of compound usually depends upon which steel type I'm working with. CPM steels (like S30V) and D2 really respond to 1 micron diamond, most other stainless alloys and carbon steel (1095) respond well to the Simichrome, and I usually reserve the green and red compound for carbon steel only.
 
For "one above" the brown stones and "one below" the white stones, what would you suggest? Is there one "between" the brown and white? I would have referenced the Grand Unified Grit chart again, but in light of our discussion it does not seem as relevant. I'm thinking: [sandpaper 1]-brown stones-[sandpaper 2]-white stones-[sandpaper 3]. What are grits 1, 2, and 3, assuming I'm using the 3m wetordry found at auto stores? We're talking FEPA-P, right?

Continued thanks for everyone's input :)
 
Dieselashi said:
For "one above" the brown stones and "one below" the white stones, what would you suggest? Is there one "between" the brown and white? I would have referenced the Grand Unified Grit chart again, but in light of our discussion it does not seem as relevant. I'm thinking: [sandpaper 1]-brown stones-[sandpaper 2]-white stones-[sandpaper 3]. What are grits 1, 2, and 3, assuming I'm using the 3m wetordry found at auto stores? We're talking FEPA-P, right?

Continued thanks for everyone's input :)
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I'm not sure it's even necessary or desirable to try to fit sandpaper in between the brown & white stones. More likely to be counter-productive. I'd recommend against it. If used with care, the white stones should remove most/all of the scratches produced with the brown stones. I really don't believe using the sandpaper will do any better.

At the low grit end, before the brown stones, I think anything from 220/320/400 (for setting the bevel) up through maybe 800 or 1000 would be fine. As mentioned earlier, the brown (medium) Spyderco hone is roughly in the ballpark of 1200 grit wet/dry (FEPA-P), in terms of the finish it leaves. So, stopping just shy of that before the brown stones, at around 1000 grit, would seem to make sense. If you take your time and use very light pressure with the white stones, I wouldn't see much need for sandpaper below 2000 grit, at the high end. Anything beyond that is up to you, how high you choose to take it.

Having said all that, I personally wouldn't think it'd be necessary to mix a sandpaper scheme with the ceramics, at all. I'd use the full range of sandpaper up through 2000 grit to set & polish the bevel, then use the ceramics for lightly touching up the very edge (micro bevel) down the road, as it needs it. OR, just use the sandpaper for everything.
 
I think OwE summed it up pretty well, actually. I'd be tempted to use the sandpaper taped to the rods in the 30 degree slots, and if that doesn't hold up the way you would like it to, just use the ceramics in the 40 degree slots for quick microbevel.
 
Which series of 1/2 inch triangulars are recommended for the Sharpmaker? I see everything from ruby to alu. oxide to diamonds.
 
There is lots of options from cheap and simple to complex and expensive.

A step above the UF rods would be 1 micron diamond compound.

A step below, Norton combo India, DMT Coarse, congress stones to fit the SM....

I would avoid sandpaper unless you only have the need for heavy stock removal a handful of times a year, it works fine but has a limited work time because the abrasive is constantly breaking down when in use. After the first re-profile a piece of 320 is more like 600, great for grit progression but a headache if you need to do more than one knife.

BTW, where are you located? Makes a difference for the grit rating you are using.
 
Me? Stephenville, Texas, near Ft Worth. I planned on just ordering the 1/2 inch triangular stones straight off of Congresstool's site.
 
No, the OP. I see he's using a European grit standard which could be confusing if in the USA.
 
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