I seem to remember that when you sent metal away for polishing you were asked what colour finish did you want, as in white, yellow, blue etc. All gave a different finish while the finished metal still looked highly polished. Jumping from a 10K stone to a 0.25 micron strop is a big move and will just polish the peaks of the edge left by your previous stone you wont end up with a 0.25 micron edge, not even sure if steel will take such a fine edge anybody know? I sometimes move from a Sigma 13K to a 1 micron diamond loaded balsa strop, although the Sigma is rated at sub 1 micron the edge still ends up more polished and feels sharper. I do what Matthew says above and use the same 1 micron strop to refresh a plane or chisel edge, with care you do not round your edges and that balsa strop appears to have work hardened quite well and stays flat enough. You will get a different edge using chromium compared to diamond.
Chromium oxide bars, or not?
- Thread starter swagman
- Start date
Help Support UKworkshop.co.uk:
matthewwh
Established Member
That's where particle shape comes in.
Diamonds are essentially pointy - cubes and pyramids - so no matter how fine you go they still leave grooves.
Chromox and rouge are much rounder - like balls with facets - so it makes things smoother rather than just replacing with finer scratches.
I suppose it's like trying to carve a flat surface with ever smaller V tools or switching to a shallow gouge.
Diamonds are essentially pointy - cubes and pyramids - so no matter how fine you go they still leave grooves.
Chromox and rouge are much rounder - like balls with facets - so it makes things smoother rather than just replacing with finer scratches.
I suppose it's like trying to carve a flat surface with ever smaller V tools or switching to a shallow gouge.
essexalan":g3zpwanz said:
If the diamond is fairly concentrated, you'd be surprised how fast it would remove material. I wouldn't really see the point with 0.25 diamond, but some do, I guess. It is a regimen step for the super stroppers in the world of razors who haven't yet looked at history (and probably a good thing for the people who hone razors for pay as it sort of completes an edge that may be a little incomplete otherwise - which can happen when you don't get to use the razor to examine its fitness).
I like autosol and 1 micron diamonds as the two things I'd screw around with in woodworking. 1 micron diamonds charge a jasper nicely to remove wire edges quickly on stuff that jasper normally wouldn't like. Autosol and dursol are nice on a hard leather wood backed strop, and easy to work with. If the diamond concentration is up high, though, even sub micron diamonds will create a tiny ragged edge that's toothy - sometimes that feels sharper in certain cuts.
It gets really hard to see what's going on at that level of groove size, though, it takes something other than optical microscopes to really see what's going on, and your exact point is one that's up for debate sometimes on the razor forums - does the grain structure of the metal even support scratches that small or is it just a waste of time? I don't know the answer to that, certainly you can groove individual carbides with diamonds, but is it worthwhile? Not sure - it does give one transient very sharp shave, though - one that trims off pimples and undulations on your face if your skin is sensitive and not hard and flat.
An autosol stropped edge that has been subsequently stropped with a bit of clean leather is incredibly sharp, I don't know if any of the items mentioned above could be discerned as any sharper in a blind test. Out of experimentation this year, I bought a $1 aluminum oxide stone at the dollar store, stropped the result of that stone hard with a strop with dursol on it and then palm stropped it until it was able to pass the hanging hair test - on a common marples parer that is of modern alloy - it essentially has zero chance of holding the edge for any material amount of time.
Unfortunately it varies as does chromium oxide (for anyone unaware, no green stropping compounds should be assumed to be equal to another). The nature of the source and what the rouge is being sold for give some clue as to how fine it might be but you pays your money and takes your chance. I've got some rouge paste that came with some small polishing mops I bought years ago that's noticeably gritty, so nothing like rouge can be: when suspended in oil it can feel little different to the oil itself when rubbed between the fingertips. This is an old jeweller's or clock-maker's tip for determining how good a given rouge was, with warnings not to use anything coarser.Cheshirechappie":138vwnm0 said:
Like most stropping this should be an either/or with any approximately equivalent fine stone. If your stropping abrasive has a particle size roughly that of your final stone (and your technique is good) stropping is supposed to degrade the edge.Cheshirechappie":138vwnm0 said:
That's mainly what I use a strop for. Stropping is my 'honing' step most of the time when sharpening and I used it to touch up an edge when it's gone just that bit blunter than it should be.matthewwh":1s9kk5p1 said:
As you say there comes a point when you can't get back to properly sharp by stropping, which I find much more frequently the case with plane irons than chisels or knives.
Don't wince but that would be worth paring down to and lifting out with your sharpest chisel. I presume you have more calloused palms than I do so if you're careful you won't cut yourself and it won't hurt.matthewwh":1s9kk5p1 said:
Warning: this medical advice provided free of any warranty.
My stropping compound supposedly contains sub-0.5 micron aluminium oxide. I recently trialled using it straight after a 1000 grit diamond plate and whether it polished off the peaks only or not it definitely improves the edge.essexalan":30dvia33 said:
This diamond plate is new, so presumably we can take it as a given that it's a shade coarser than the stated grit.
According to a book I have by Rudolf Dick the finest cutting edges measured on a razor were 0.5 microns, the finest edges edges are from obsidian chips which are more than a hundred times thinner and are still used in microtomy. Bit brittle for carpentry though. I like stropping it makes the edge feel better and all these compounds are worth trying to find one that suits you, finishing on a plain hard, flat piece of leather and you can do no more. Bit of a waste of time when you are whacking out mortises though.
I have seen people shaving with obsidian on youtube and for some reason, the sharpness did not translate to what the fineness would suggest. It's not something I'd try, but I was curious to see if they'd shave off every bump (the thinner an edge is- presuming it's polished - the lower the angle that it will catch on something). It probably isn't that durable (as in, the immediate edge after sharpness probably gets beat up by facial hair, etc)
A properly stropped 0.5 micron razor edge will draw blood on my face. If the edges are no finer than those particles in width, the other stuff would seem like a waste. I did notice a difference in keenness further with iron oxide (.09 microns and soft cutting), it was downright uncomfortable in the ability to remove every tiny undulation, and not just the pronounced ones. Not desirable.
All of the above a complete waste of time for knives and tools, though.
re: the jeweler's rouge, I have gotten two different sticks of iron oxide rouge that called itself jeweler's rouge but obviously had aluminum oxide in it. It wasn't from a jewelry supply place. I guess most makers of the cheap stuff can't resist the urge to make it cut faster.
A properly stropped 0.5 micron razor edge will draw blood on my face. If the edges are no finer than those particles in width, the other stuff would seem like a waste. I did notice a difference in keenness further with iron oxide (.09 microns and soft cutting), it was downright uncomfortable in the ability to remove every tiny undulation, and not just the pronounced ones. Not desirable.
All of the above a complete waste of time for knives and tools, though.
re: the jeweler's rouge, I have gotten two different sticks of iron oxide rouge that called itself jeweler's rouge but obviously had aluminum oxide in it. It wasn't from a jewelry supply place. I guess most makers of the cheap stuff can't resist the urge to make it cut faster.
According to the book these are just splinters chipped off the way they have done it for thousands of years. Sharp enough and neutral to flesh tissue they are used in eye surgery and for slicing flesh tissue down to 0.1 micron. I don't know but I suppose there are different types of sharp edge on a razor and I would think a diamond strop would leave a "raggy" edge while softer abrasives would give that smoother edge. I did make up some chrome dioxide paste from 0.5 micron powder and mineral oil but it is messy stuff. You can source all sorts of these powders from makers of artists oil paints in the form of pigments.
Cheshirechappie
Established Member
Thanks to those who responded to my rouge question.
I did bit more rummaging on the size of haematite particles as used in jeweller's rouge, and came up with one source that suggested 3.5 to 5 microns; I'm not sure I'd take that to be the final, definitive answer, though. Given the range of uses for haematite from blast-furnace feedstock, paint pigments ('red oxide'), polishing and probably many others, there's a fair chance that it can be obtained in a wide range of sizes, and those sizes separated and graded to a greater or lesser degree.
On the subject of the effectiveness of different abrasives, there's another factor that will complicate things a bit - that some plastic deformation of metal will take place at the cutting edge of a tool being honed or stropped (or a metal being polished). The amount of deformation will (probably) be less the harder the workpiece, but it'll still be there, and grits with a more rounded shape will tend to promote more deformation - burnishing, if you like - than cutting. The sharper-edged grits, like diamonds, are more likely to scratch and cut than promote burnishing. (I suspect that may go some way to explaining why some honing stones give better edges that their grit size might suggest, as well.)
As always, it's probably best to go with what works for you. If you're consistently getting the edges your work demands, stick with whatever you're doing even if the gurus tell you you're doing it all wrong.
I did bit more rummaging on the size of haematite particles as used in jeweller's rouge, and came up with one source that suggested 3.5 to 5 microns; I'm not sure I'd take that to be the final, definitive answer, though. Given the range of uses for haematite from blast-furnace feedstock, paint pigments ('red oxide'), polishing and probably many others, there's a fair chance that it can be obtained in a wide range of sizes, and those sizes separated and graded to a greater or lesser degree.
On the subject of the effectiveness of different abrasives, there's another factor that will complicate things a bit - that some plastic deformation of metal will take place at the cutting edge of a tool being honed or stropped (or a metal being polished). The amount of deformation will (probably) be less the harder the workpiece, but it'll still be there, and grits with a more rounded shape will tend to promote more deformation - burnishing, if you like - than cutting. The sharper-edged grits, like diamonds, are more likely to scratch and cut than promote burnishing. (I suspect that may go some way to explaining why some honing stones give better edges that their grit size might suggest, as well.)
As always, it's probably best to go with what works for you. If you're consistently getting the edges your work demands, stick with whatever you're doing even if the gurus tell you you're doing it all wrong.
No skills
Established Member
Little late an maybe no use but found this description...
"Red is also called Jewellers Rouge ( Rouge is simply the French word for Red ) it is used by Jewellers for polishing Gold, Silver, Pewter, Nickel, Platinum, Glass and Soft metals. Just like all Buffing bars, however not all Rouge Buffing bars are the same, because the vast majority of buffing bars are made in India and China, there Rouge is only a dye colour thats added and combined with some fine abrasive, in many cases its just fine silica (sand) but thats not good quality Jewellers Rouge they just cheap copies, that can corrode the surface of what its intended to polish. Our Rouge buffing bars are different, because the colour of our Rouge bars comes as it traditionaly should, from the abrasive itself, we use a special high quality grade of Iron (111) oxide abrasive and that produces an ultra fine finish and the abrasive colour enhances the colour of gold, which is why our Rouge is the choice of Jewellers. Rouge is recommended for use with a Loose leaf buffing wheel (or any type of soft buffing wheel). Rouge is also used the optics industry to polish Glass. Red has a very slow, ultra fine cutting action and gives a mirror like finish. Rouge has the very lowest cut rating of 1, so you need to get the metal to a good standard before using rouge in order to achieve a mirror finish. "
Nothing about particle size but interesting that cheap abrasive bar could contain a complete different medium than your expecting...
"Red is also called Jewellers Rouge ( Rouge is simply the French word for Red ) it is used by Jewellers for polishing Gold, Silver, Pewter, Nickel, Platinum, Glass and Soft metals. Just like all Buffing bars, however not all Rouge Buffing bars are the same, because the vast majority of buffing bars are made in India and China, there Rouge is only a dye colour thats added and combined with some fine abrasive, in many cases its just fine silica (sand) but thats not good quality Jewellers Rouge they just cheap copies, that can corrode the surface of what its intended to polish. Our Rouge buffing bars are different, because the colour of our Rouge bars comes as it traditionaly should, from the abrasive itself, we use a special high quality grade of Iron (111) oxide abrasive and that produces an ultra fine finish and the abrasive colour enhances the colour of gold, which is why our Rouge is the choice of Jewellers. Rouge is recommended for use with a Loose leaf buffing wheel (or any type of soft buffing wheel). Rouge is also used the optics industry to polish Glass. Red has a very slow, ultra fine cutting action and gives a mirror like finish. Rouge has the very lowest cut rating of 1, so you need to get the metal to a good standard before using rouge in order to achieve a mirror finish. "
Nothing about particle size but interesting that cheap abrasive bar could contain a complete different medium than your expecting...
swagman
Established Member
0.3 micron http://www.workshopheaven.com/tools/Chr ... tml#SID=48
The following site is a Micron to Grit Size Converter. http://www.rahulgladwin.com/docs/micron ... ersion.php
Entering the value of 0.3 micron;
(grit size equivalent) = 80,930.38
The following site is a Micron to Grit Size Converter. http://www.rahulgladwin.com/docs/micron ... ersion.php
Entering the value of 0.3 micron;
(grit size equivalent) = 80,930.38
swagman
Established Member
The largest particle size in the green honing rouge bars is 300 mesh. (169 times greater than .5 microns.) = 84.5 micron.
http://straightrazorplace.com/honing/28 ... s-not.html
swagman
Established Member
The main lesson from this discussion, is that from a buyers perspective, we will continue to be at the mercy of the retailer, and manufacturer, to accurately describe the range of micron sizing contained within these polishing compounds.
Stewie;
Stewie;
bugbear
Established Member
swagman":37tejenj said:
No, you can't say that. The language used is very careful.
"Actually that’s a trade determination that simply says nothing in the abrasive is coarser than 300 grit".
So all that's stated in that spec is less than or equal to 300 grit. TBH, in the context of sub micron particles, it effectively tells us nothing. (it's obvious from the evident performance that there are very few circa 300 grit particles in the Veritas product).
It's like saying a road car's top speed is no higher than 200 MPH. Accurate, true, and unhelpful.
BugBear
bugbear
Established Member
BTW, my source for strop dressing was my local graphic arts shop. I bought a "proper" artists Chromium Green oil pastel. Just scribble it on.
Given the amount of dressing needed on a strop (I suspect many people are using too much, judging by the strop cleaning processes described recently), it will outlast me.
BugBear
Given the amount of dressing needed on a strop (I suspect many people are using too much, judging by the strop cleaning processes described recently), it will outlast me.
BugBear
When I was a kid cut throat razors were common place in barbers shops. I often used to see the barber stropping a razor ready for a customer as I waited my turn for a hair cut. The strop looked little more than a shiny leather belt with no obvious compound on it that I can recall. I too suspect some folks are putting far too much product on them.
memzey
Established Member
The razor stuff is actually quite interesting but it in terms of woodwork I'm genuinely unsure as to what the merits of going to such degrees of fineness (if that is the right term) are. Are there some tasks that demand such a level in order to be performed? How long does such a keen edge last in typical tool steels? I only ask as my sharpening regimen is Neanderthal by comparison but I can still easily and cleanly pare softwood end grain as mentioned above, shave hair on my arms and take sub-thou' shavings on a smoother, all of the things I assumed you needed really sharp tools for. Is there something or some area of woodwork, like luthiery perhaps, that I'm not aware of where the benefits of these steps present themselves?
bugbear
Established Member
memzey":hvya2bhw said:
Jeff Gorman's site used to quote some research (some forestry organisation, IIRC) showing that finely polished edges last longer than coarsely finished edges.
BugBear
A more refined edge is desirable when your final cuts are the finish I would have thought, carvers are particularly fastidious with their cutting edges. I heard/read that about polished edges lasting longer but I don't know how true it is.
Similar threads
