Strop Compound Colors

[Pima Pants]

I recently received a strop that I ordered and it came with directions about how to use it. It has two sides, a rough suede and the other side is very smooth. What wasn't included were instructions on how to use the green compound or the white compound that came with it. I have used strops before but not with compounds. Any advice is appreciated.

 

[BitingSarcasm]

The color of the compound tells you what level of grit it is, but it doesn't seem like there is a whole lot of agreement between manufacturers on what color means what. I have a green that's relatively coarse and a much finer white, and another white from a different brand that's somewhere between the 2. If there's a brand on the container, that will help greatly in looking it up. Otherwise, there are some good tutorials in old threads on loading strops with compound, and everyone has their favorite method. I like to heat up the coarse green until it's a bit softer, then scribble it on. I use a rougher leather for the coarse, and fine compound on the smooth side of the leather for polishing. I could be doing it completely wrong, but it works well enough for me.

 

[Obsessed with Edges]

Compounds would be better described in terms of their aggressiveness at polishing, rather than actual grit size or fineness. The actual size of the grit won't necessarily determine how it finishes a particular steel. 'Green' compound, if it's pure, will usually be a very fine chromium oxide at around 0.5 - 1 micron in size. It's not very hard either, as compared to a 'white' compound (usually aluminum oxide). So, between green's small size and lesser hardness, it won't be as aggressive a polisher as will be the aluminum oxide.

Because aluminum oxide is harder than chromium oxide, its 'white' versions can be very aggressive polishers on steels with a little more wear resistance - these would be stainless steels like 420HC, 440A/C, 154CM, VG-10, etc. Even though a 'green' chromium oxide might be smaller ('finer') and less hard, it'll struggle to fully polish some of these steels - so it won't leave as fine a finish, if there are many coarse scratches in the steel.

'White' aluminum oxide compounds can vary more in size (I use one that's rated at 2-5 microns). But with moderately wear-resistant steels as mentioned above, it'll be a better polisher than will the green.

Green compounds will polish well with simple carbon steels (1095, CV, etc.), because those steels have much less wear resistance in the form of hard carbides that would otherwise be found in the stainless steels mentioned earlier.

Best way to evaluate how they work is just to use them. You might test them first on plain paper laid over your bare strop, so you can get a feel for how they fit in a polishing sequence. When you have a better feel for that, then you can go ahead and load your strop with your preferred compound.

For me, if I have a 'green' and a 'white' compound - I'd make my choices based on what steels I'm working with, as explained above. I wouldn't generally use both in a sequence however, as they both can produce similar results on their own when chosen for a specific steel based on its wear-resistance alone.

 

[Pima Pants]

Thank you gentlemen for your advice. I really appreciate it.

 

[CutterBoi]

Like BitingSarcasm and Obsessed with Edges said, the advertised "grits", "microns", and even abrasive materials of the various color compounds are all over the place. You can find all sorts of compounds on Amazon and Ebay but how is a person to know what they actually represent? How are we supposed to compare them? Some listings provide no information other than color! And what about production consistency? How do we know that the compound a company puts out today is the same as what they put out yesterday? Makes me wonder whether people doing industrial grinding / lapping / polishing use better-documented, maybe certified compounds and, if so, where I can get my hands on more information. And something else to muddy the picture: the substrate onto which a compound is loaded has an impact on the finish produced by that compound. A white compound loaded onto a sheet of metal may produce a different finish than the same compound loaded onto suede leather. Abrasive properties are a rather complex subject.

FYI, someone representing Sharpal on Amazon said, "SHARPAL green compound is comprised of Aluminum Oxide and Chromium Oxide at small grit size around 1 micron."

 

[Obsessed with Edges]

That blending of compounds, like the SHARPAL green w/AlOx & CrOx, is another big variable with these compounds and really complicates predicting how they'll work. Some manufacturers of stick-type compounds will actually number them for a sequence - like '1' to be used first and '5' to be used last - which sometimes makes it easier if no other guidelines exist. But even then, some of the compounds in that numbered sequence may not be best for the given metal or steel being polished and would better be left out of a sequence for a particular type of metal, like hardened steel. Some compounds are better suited for softer metals like brass or jewelry-grade metals (gold, silver), or even plastics, but will be ineffective or very slow to work on hardened stainless steels. And again, some stick-type compounds will also be labelled as best-used for particular metals. The aluminum oxide 'white rouge' I referenced earlier, a Ryobi compound at 2-5 microns, is labelled as best-used for stainless steel, for example. That's pretty common labelling for white aluminum oxide in particular.

Sequencing of compounds only by grit size is really only useful if all the grits used in the sequence are of the same type from a single manufacturer, with other variables like purity & uniformity of grit shape, hardness, toughness, etc. all being essentially equal. An example would be an all-diamond sequence as from DMT - their compounds sequence very seamlessly and are therefore very simple to predict results.

 

[Pima Pants]

Thank you, Cutter and Obsessed. I appreciate the additional information.

 

[Blade Lab]

One way to avoid the uncertainty is to make your own emulsion. It's very simple to create one with chromium oxide. Just buy a jar of CrO2 powder and mix it with mineral or linseed oil until it forms a gooey paste. Pure CrO2 powder has a grain size between .2 and .5 microns, so it averages out to around .35 micron. I use that mixed with some .25 or .5 micron CBN emulsion. Works great on leather belts, but it would also apply very easily to a leather strop. Much easier to apply than those crayon stick compounds.

 

[Obsessed with Edges]

One way to avoid the uncertainty is to make your own emulsion. It's very simple to create one with chromium oxide. Just buy a jar of CrO2 powder and mix it with mineral or linseed oil until it forms a gooey paste. Pure CrO2 powder has a grain size between .2 and .5 microns, so it averages out to around .35 micron. I use that mixed with some .25 or .5 micron CBN emulsion. Works great on leather belts, but it would also apply very easily to a leather strop. Much easier to apply than those crayon stick compounds.

I've done it that way, mixed with mineral oil. Picked up the dry powder at a lapidary/rockhounding hobby supply. Nice thing about mixing it this way, with mineral oil, is that it can basically be 'painted' onto any material you choose, in a very even & dense coat. Just need to be very careful handling the dry powder so it doesn't get airborne - it's a hazard to the lungs and also makes quite the green-stained mess if it spills.

I liked it best as used on MDF, as seen in the green piece in the stack below. I used that for woodworking chisels, mainly.

 

[Rt88man]

I've done it that way, mixed with mineral oil. Picked up the dry powder at a lapidary/rockhounding hobby supply. Nice thing about mixing it this way, with mineral oil, is that it can basically be 'painted' onto any material you choose, in a very even & dense coat. Just need to be very careful handling the dry powder so it doesn't get airborne - it's a hazard to the lungs and also makes quite the green-stained mess if it spills.

I liked it best as used on MDF, as seen in the green piece in the stack below. I used that for woodworking chisels, mainly.

lol it’s a hazard to the lungs. Wow. You really think you will have lung problems from putting on stropping compounds? Geez cutting a two by four is a hazard but you will be just fine. Don’t worry about stropping compounds affecting your lungs. Come on that’s a little insane.

 

[Obsessed with Edges]

lol it’s a hazard to the lungs. Wow. You really think you will have lung problems from putting on stropping compounds? Geez cutting a two by four is a hazard but you will be just fine. Don’t worry about stropping compounds affecting your lungs. Come on that’s a little insane.

In the green stick form or liquid forms, no worries about hazards to the lungs. But in the fine POWDER form I clearly referenced, it's a risk for inhalation into the lungs, as would be any fine airborne dust generated by sharpening activities. This green powder is extremely fine and gets airborne easily.

 

[knucklegary]

I'd be more worried about accidentally getting the mixture in your eyes, wear safety glasses and gloves.

Here's some good information on stropping razors and mixing procedure..

Chromium Oxide (Green) 100gr

Chromium oxide is an indispensable product for experienced straight razor users. 100 grams of CrOx is more than sufficient for a lifetime use.

www.razorus.com

 

[Obsessed with Edges]

I'd be more worried about accidentally getting the mixture in your eyes, wear safety glasses and gloves.

Here's some good information on stropping razors and mixing procedure..

Chromium Oxide (Green) 100gr

Chromium oxide is an indispensable product for experienced straight razor users. 100 grams of CrOx is more than sufficient for a lifetime use.

www.razorus.com

I noticed, when using the powder, it's so fine it would essentially embed into the surface pores of almost anything it touched. I was working at the sink and just tiny amounts of the powder falling into the sink would immediately stain the enamel and needed some scrubbing to clean it up. So, it occurred to me also, that any on the fingers would also be a risk if rubbing the eyes or whatever.

 

[jeffbird]

I noticed, when using the powder, it's so fine it would essentially embed into the surface pores of almost anything it touched. I was working at the sink and just tiny amounts of the powder falling into the sink would immediately stain the enamel and needed some scrubbing to clean it up. So, it occurred to me also, that any on the fingers would also be a risk if rubbing the eyes or whatever.

OWE,

Have you tried diamond sprays? I am using Ted Pella 0.25 micron diamond spray on a horsehide strop for my straight razor. It crisps the edge up just enough to really maintain the edge and go months between needing to go back to the stones. 0.1 micron did not provide the same effect, so 0.25 micron is the smallest I now use.

They offer diamond sprays into much larger sizes too. To me, the diamond spray is less messy than green material, or at least less noticeable.

The article you linked above indicates green paste is 0.5 micron, which matches with the somewhat finer face feel coming off of the 0.25 micron. Also, the 0.25 micron is a noticeably crisper feel than plain leather alone.

 

[SwissHeritageCo]

OWE,

Have you tried diamond sprays? I am using Ted Pella 0.25 micron diamond spray on a horsehide strop for my straight razor. It crisps the edge up just enough to really maintain the edge and go months between needing to go back to the stones. 0.1 micron did not provide the same effect, so 0.25 micron is the smallest I now use.

They offer diamond sprays into much larger sizes too. To me, the diamond spray is less messy than green material, or at least less noticeable.

The article you linked above indicates green paste is 0.5 micron, which matches with the somewhat finer face feel coming off of the 0.25 micron. Also, the 0.25 micron is a noticeably crisper feel than plain leather alone.

I wonder about people breathing that stuff in too.

 

[Obsessed with Edges]

OWE,

Have you tried diamond sprays? I am using Ted Pella 0.25 micron diamond spray on a horsehide strop for my straight razor. It crisps the edge up just enough to really maintain the edge and go months between needing to go back to the stones. 0.1 micron did not provide the same effect, so 0.25 micron is the smallest I now use.

They offer diamond sprays into much larger sizes too. To me, the diamond spray is less messy than green material, or at least less noticeable.

The article you linked above indicates green paste is 0.5 micron, which matches with the somewhat finer face feel coming off of the 0.25 micron. Also, the 0.25 micron is a noticeably crisper feel than plain leather alone.

At times, including recently, I'm tempted to experiment some more with diamond compound, and the sprays in particular. I've previously used DMT's Dia-Paste compound, but have never tried any sprays yet. I'm hesitant because I've settled into a habit of not relying much, or at all, on compounded strops anymore. Any stropping I do these days is just on bare leather or occasionally bare paper laid over a stone.

The green lapidary powder I used as described was done basically as an experiment, years ago. It definitely can be messy, in making compound with it. But after the powder & mineral oil mix dried on the MDF, very little of it comes off again. Then it's not so messy in use.

 

[jeffbird]

The Ted Pella 0.25 micron diamond spray provides a noticeable improvement in the edge over bare leather. For knives, there may be no real benefit, but on a straight razor, there is a real improvement in edge performance over bare leather that is felt on the face.

fwiw - I started using a straight razor after seeing an old interview with A.G. Russell in which he said, “if you want to really learn to sharpen, use a straight razor.” So I started from that challenge and now wish I would have done it decades earlier.

 

[Obsessed with Edges]

The Ted Pella 0.25 micron diamond spray provides a noticeable improvement in the edge over bare leather. For knives, there may be no real benefit, but on a straight razor, there is a real improvement in edge performance over bare leather that is felt on the face.

fwiw - I started using a straight razor after seeing an old interview with A.G. Russell in which he said, “if you want to really learn to sharpen, use a straight razor.” So I started from that challenge and now wish I would have done it decades earlier.

Straight razors are another thing I've been tempted to experiment with, purely for the sake of building sharpening knowledge. As I've gotten older, I essentially gave up shaving anymore and let my stubble grow, sometimes to a pretty scruffy beard that doesn't get trimmed back until I cut my hair. So, for shaving's sake, I don't plan to spend much $$ on that either anymore. But I'm still intrigued with straight razors anyway. Might give that a go, one of these days.

 

[knucklegary]

Has anyone here tried kangaroo hide, for either razors or knives?
Curious to how it works compared to horsehide.
I found a source on Etsy but shipping from Australia makes buying cost prohibitive, imo

 

[Tensaw]

Has anyone here tried kangaroo hide, for either razors or knives?
Curious to how it works compared to horsehide.
I found a source on Etsy but shipping from Australia makes buying cost prohibitive, imo

When sharpening on a K03, my last step is to strop with a kangaroo leather strop loaded with 6 micron Gunny Juice. The kangaroo seems harder than cow leather.