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Cant get a proper mirror finish with green chromium oxide.
- Thread starter Nogorn
- Start date
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- Dec 19, 2011
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- 795
Heres a couple questions just to get things rolling.
What are you sharpening with currently? What is your current progression of stones. You need a tightly controlled progression to get a true mirror.
What "green compound" are you using. The only chromium oxide i would be would be the stuff sold by Hand American. Most green compounds have such a huge particle size distribution that it would be physically impossible to create a perfect mirror even if you stropped till your arms fall off.
What are you sharpening with currently? What is your current progression of stones. You need a tightly controlled progression to get a true mirror.
What "green compound" are you using. The only chromium oxide i would be would be the stuff sold by Hand American. Most green compounds have such a huge particle size distribution that it would be physically impossible to create a perfect mirror even if you stropped till your arms fall off.
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- Apr 12, 2009
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Biggest factor is making sure to take baby steps in grit size reduction. Need to keep the jumps in grit as narrow as possible; if they're too wide, the very small particle size of the green compound won't be able to fix the much-heavier scratches left by previous grit steps.
AND, with green stick/crayon-type compound in particular, the quality and purity of many of them isn't very good. Many are blends of green (chromium oxide) and other abrasives, like aluminum oxide. It's not uncommon for some of them to leave a hazy finish, in spite of doing the proper work prior.
David
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- Apr 12, 2009
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Sandpaper? If so, going further in the sequence through 2000+ grit will likely be necessary, before green can be most effective. Or if not, what abrasives/stones are you using? I ask this, because different abrasives are usually graded by different grit standards.
David
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- Apr 12, 2009
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What does the edge finish look like off the 1600 grit stone? And what steel are you attempting to sharpen, in this case?
If the steel has much more alloy content than something very basic, like 1095, green compound won't work very aggressively to polish anyway. It can, over time, put a fairly high polish on 1095 or Case's CV. Virtually no abrasion-resistance in those steels, so green compound can still work pretty fast. Stainless steels and high-carbide content steels (D2, S30V, etc.) won't polish on green nearly as easily, if the edge finish isn't already very nearly-mirror.
David
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- Jan 25, 2012
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Go 180, 220, 320, 400, 600, 800, 1000, 1200, 1500, 2000, then compound. Mirror for days!
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On most steels, it should shave coming from that stone, or even from coarser stones. Could be one/several issues, but incomplete apexing of the edge is usually responsible for that. Since these stones are an unknown, in terms of actual abrasive type or grit size (in spite of their labelling), that may be complicating things. And on an S30V blade, they may not be aggressive enough to shape the carbides in it anyway. Diamond is better for S30V, in that regard, and also for stropping afterwards (or CBN compound has a good rep with it, as well). S30V won't hone to a very fine edge on sub-standard abrasives at all, as the very hard vanadium carbides in the steel won't respond to them in a good way.
If you're also seeing the 'hazy' finish off the green compound with softer steels, it may be worth finding a green of a known and better reputation. Sounds like the stuff you have may be mixed abrasives, or inconsistent in grit size, or both.
David
Thank you. I form a bur on the edge with every stone and my blades can whittle hair but dont have a mirror polish, thats why im so confused.. I think im going to upgrade to the Edge pro apex $245 kit (Apex 4 kit) when i get enough money after i buy a car. IOr do you think i should get the edge pro with chosera stones for $330? It looks like the edge pro stones are much finer on his grit chart.
^Something doesn't make sense. Your "blades can whittle hair", but a few posts above your S30V blade "will not shave at all". That's rather contradictory. Are you after sharp, or are you after a mirror look? Or both?
I think mirror polish starts in the neighborhood of 2000 ANSI, 4000 JIS, or 3 micron abrasive size. With waterstones, I can jump from a 1k Nubatama Ume to a 5k Nubatama bamboo and get a nice mirror polish. Probably not nearly as pure as something from a finer grit progression, but it's quite obviously mirrored. It's also very, very sharp as long as I do my part with burr formation and removal.
On the other hand, I could make it mirror polished and have very little sharpness at all if I didn't apex the edge. Looks, but no sharpness.
Or I can get some fairly impressive sharpness, including shaving hair easily, from a DMT Coarse, and a tiny bit of stropping. That edge doesn't look impressive, but it performs well.
If you want both, you just want to do a progression that ends with at least 2-3k ANSI or 4k+ JIS. I've seen Jdavis go from around 1200 grit (Spyderco fine) to 3 micron (Spyderco Ultrafine) and make an impressive mirror polish.
Brian.
I think mirror polish starts in the neighborhood of 2000 ANSI, 4000 JIS, or 3 micron abrasive size. With waterstones, I can jump from a 1k Nubatama Ume to a 5k Nubatama bamboo and get a nice mirror polish. Probably not nearly as pure as something from a finer grit progression, but it's quite obviously mirrored. It's also very, very sharp as long as I do my part with burr formation and removal.
On the other hand, I could make it mirror polished and have very little sharpness at all if I didn't apex the edge. Looks, but no sharpness.
Or I can get some fairly impressive sharpness, including shaving hair easily, from a DMT Coarse, and a tiny bit of stropping. That edge doesn't look impressive, but it performs well.
If you want both, you just want to do a progression that ends with at least 2-3k ANSI or 4k+ JIS. I've seen Jdavis go from around 1200 grit (Spyderco fine) to 3 micron (Spyderco Ultrafine) and make an impressive mirror polish.
Brian.
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Now this is what I referred to earlier, in that a shaving edge can/should happen at any but the coarsest of grits. A mirror polish has no direct role in that aspect, and isn't necessary to get a shaving or hair-whittling edge. To get a mirror polish, the steps in grit need to get much narrower, so the scratch patterns can be effectively reduced at each & every step. The apex itself is what needs to be fully sharp at any finish, and the finish on the bevels, by itself, won't make an edge shaving-sharp if the edge isn't fully apexed to begin with.
David