polishing compounds

[Eytan (Ethan) K]

Hello,

can anyone tell me the difference between the polishing compounds (in the photo?)

I use the green and the white, the seems a bit more gentle (the blade is sharper).

Thank you.

 

[HeavyHanded]

Generally, the black is a coarse aluminum oxide, the white is a fine aluminum oxide, the green is a fine chromium oxide, the red is ferric oxide. The red is generally unsuitable for polishing cutlery - used to put a polish on non-ferrous metals, but the other three all will work well on most steels.

 

[Eytan (Ethan) K]

Thank you, in one sentence you made things very clear to me.

Thank you again.

 

[Bill DeShivs]

While red rouge doesn't cut rapidly, it was used for many years to finely polish high carbon knife steel.

 

[phillipsted]

I've never been able to figure out when to use white vs. green. They seem to perform similarly - but I would assume the green, being chromium, would be more aggressive. The green definitely seems to be harder to clean up (it gets green/black goop into all sorts of nooks and crannies!). Thoughts?

TedP

 

[james terrio]

I've never been able to figure out when to use white vs. green. They seem to perform similarly - but I would assume the green, being chromium, would be more aggressive. The green definitely seems to be harder to clean up (it gets green/black goop into all sorts of nooks and crannies!). Thoughts?

I have no thoughts, except to say that my experience is very much like yours... they both work well for my purposes but the green is a bit messier. I admit to not knowing nearly enough about polishing compounds, and look forward to more info. :thumbup:

 

[unit]

Just remember not all compounds of a certain color are the same. I have found green to be *almost* universally 0.5 micron chromium oxide, but many different carriers can be used. The waxy mess is the carrier...you can also get it in powder and liquid form (and the liquid carrier can be alcohol, water, or oil...there are probably others I have not played with).

Also, as has been stated, not all compounds are suitable for hardened blade steel.

I have found iron oxide to have minimal effects on all but the most highly refined edges...and this is only with straight razors (and trust me, these things have a very different set of goals/targets when it comes to edge finishing).

 

[Gunsnknives]

Not to go off on a tangent, but the OP might want to try Mother's Mag and Aluminum polish. It gives a bit more bite than the typical green chromium oxide (about 0.5 microns), but is abrasive enough to work on S110V and even my REX121.

And yes as previously posted, colors of compounds are not universal so it's hard to sometimes provide input.

 

[Obsessed with Edges]

I've never been able to figure out when to use white vs. green. They seem to perform similarly - but I would assume the green, being chromium, would be more aggressive. The green definitely seems to be harder to clean up (it gets green/black goop into all sorts of nooks and crannies!). Thoughts?

TedP

I'd bet the smaller average particle size of most 'green' (chromium oxide) compound is to blame. I agree, it tends to cling to & stain most anything it touches. The smaller particle size would allow it to get into the tiniest of pores. It may be the 'white' compounds will do the same, but individual particles or agglomerations of them may not be as obviously visible, tending to 'blend in' to whatever surface they're stuck to.

Green may or may not be more aggressive for it's size, depending on which 'white' compound it's compared to. 'White' aluminum oxide would likely be harder. But 'white' can also be something like tin oxide, or talc, or a mix of who-knows-what; some of which may not be as hard as chromium oxide, but may still be larger in particle size. There's a tin oxide compound misleadingly called 'white diamond', but it's very soft; only intended for soft metals. The shape of the particles makes a difference too; some will be more jagged or edgy, and cut more aggressively, while others may be more blunt/blockish/round in shape, therefore not working as aggressively, even at larger sizes.


David

 

[HeavyHanded]

From what I can tell, the chromium oxide is a bit less aggressive, has a more uniform shape than aluminum oxide. AlumOx under magnification has sharp edges and corners and is very non-uniform in shape. The AlumOx seems to work well across a wide range of steels, while the CrO seems to work best on carbon steels and relatively mild stainless.

I have a few bottles of microtome honing slurry in some sort of oily suspension, intended to be used on a frosted glass plate. I haven't taken a look at the "fine" grit yet - am 99.9% certain its alumox.