Thread: Sharpening and polishing compounds

Good to see someone else who's into sharpening by buffing wheel.

I just use a green compound from Carpatec. Quite expensive at $20 a stick. But its worth it. Means I can go straight from Aluminium Oxide wheel straight to the buffing wheel and end up with razor edge.

I'd imagine there are different types of 'green' compound. I don't know much more on the topic. All I know is the stuff I use works very well. Makes the whole sharpening process very quick indeed.

I use my buffing wheel for everything, from jointer knives to my straight razor.

But, make sure your shed's rat free. The buggers love that green compound. true.

Good luck

No ****? There teeth must be bloody sharp afterwards! We about 20 fruit trees around us so rats are a problem but I've never seen them chewin' the green.

Can anyone explain the difference between the various compounds, and tell me which ones have a role to play in sharpening, and if there is a compound that I can use to get things a bit sharper then the green.

Arron

If the green crayon is the Veritas green rouge, then it is aluminium oxide, which is rated at .5 microns. You are not going to find much "sharper" than this, that is, 0.5 microns is a very fine grade and equivelent to about a 9000 waterstone (it is incorrect to compare grits across different sharpening mediums, so this is done for illustration only).

I'm not sure what grade the red rouge is, but suspect it is about 3 microns (about 4000 waterstone).

There is an issue here, one that has been raised many times on this forum, involving going from wheel to rouge. Basically, the edge you get this way can be sharp but will not be smooth. Sharp is needed for chisels and non-finishing plane blades. Smooth is essential for finishing plane blades. Smooth and sharp gives the easiest cut. Going directly from a wheel leaves too many deep scratches, and it is these that will leave a serrated edge on the blade (feel for it - it will catch). Using a graduated series of sharpening mediums before the green rouge (e.g. 1200 and 6000 waterstones) will remove the scratches and produce a smooth edge for honing (feel it - you cut yourself, and only reallise it later). Using the green rouge directly after the wheel just polished the serrations. So you have sharp serrations.

Having said all that, I am not knocking skipping grits. It just depends what you want to do with the blade.

Regards from Perth

Derek

not sure what to call it, rouge, crayon ???

Since 'rouge' is French for red, then you could call it 'vert'
Red Rouge is a tautology

Do you guys have grinders that you can throw into reverse, or do you turn them around?

Originally Posted by derekcohen

If the green crayon is the Veritas green rouge, then it is aluminium oxide, which is rated at .5 microns.

Derek,

Actually the Veritas compound, according to the LV cattledog, is mainly chromium oxide. I am not sure how the green compound is produced, but it does not occur as an ore. The only ore of chromium is chromite, a chromium-iron oxide, which is black. I wonder whether the Veritas compound is actually finely ground uvarovite, a green chromium garnet.

Rocker

Originally Posted by silentC

or do you turn them around?

Just cheapies from Bunnings - so I turn one of them around. It is mounted vertically, of course - so I can polish freehand while watching the angle at which the blade meets the buffing wheel, which does away with tool rests.

Derek, good point you raise. I just went down to the garage and bought up some blades as I was pretty happy with their finish-planing performance. Under the magnifying glass no scratches meet the cutting surface, the tool edge feels smooth, and the planed timber is glass-smooth. Perhaps there is some misunderstanding about just how smooth an 'ultra fine' stone leaves a blade. It is possible to feel faintly perceptable scratches with the fingernail, in the hollow ground area. Its a good point though, and I dont claim certainty about any of this stuff - its all evolving technique from my point of view.

Does the point you raise also apply to Tormeks. My understanding is that they are basically just a fine grindstone followed by a buffing medium?

Arron

Actually the Veritas compound, according to the LV cattledog, is mainly chromium oxide.

Rocker, you are right. I meant chromium oxide, which is .5 microns (aluminium oxide is in oil stones and sandpaper). I need more sleep!

Regards from Perth

Derek

Does the point you raise also apply to Tormeks. My understanding is that they are basically just a fine grindstone followed by a buffing medium?

Arron

Yes. In fact, this was the subject of a reply I made on the Wood Central forum about two years ago. For interest:

First off let me say that 90% of the time I hate sharpening! Only 10% is the Zen experience for me - I'd rather be woodworking. So I have also looked seriously at alternate methods to my current (several years now) preference for waterstones. I came so close once to buying a Tormek. Perhaps I still will ... Nah, it is not good enough .. Oh I wish it were good enough ...

If you can wait through a couple of short stories, then you may understand why I feel this way.

Situation one. You buy a new plane, a decent one, and it arrives with a factory-sharpened blade. The one that made me aware of the issue was a Mujingfang Smoother. Now the blade is sharp, sharp enough to shave with. So it had got to be sharp - yes? Perhaps. Maybe not. But it feels so sharp! So you set the plane for a fine shaving and plane away. And you marvel at the whispy shavings that you produce. BUT then you look carefully at the surface of the timber you have just planed and you notice that it is really not as smooth as you thought it would be. In fact, it has a grainy, slightly rough texture. Mmmm.

Situation two. I attend a Woodshow where the Tormek is being demonstrated by an enthusiastic salesman (or should that be "salesperson"). I am equally enthusiastic, particularly since I have a memory of seeing The Norm using one and slicing newsprint with his chisels after this. The salesman shows me how it is set up, how you change the grits, and how you hone on the leather wheel after the fine wheel has ground the bevel. He slices and dices as well as Norm. Then he hands me the plane blade and I run a finger tip over it. What's this? It feels rough! The salesman assures me the blade is sharp - well I saw him slice newsprint, didn't I? Well, for me a sharp blade should feel smooth, in fact should not feel sharp at all.

So I know that, if I used this blade, it would leave the same rough surface that I experienced with the factory-sharpened Mujingfang. The Tormek grinds to 1000 grit. This is nearly where the lowest Waterstone I use (800) begins. My next up is a 1200, then a 6000 and finally a natural waterstone. If I then hone (with Veritas green) I end up with a mirror surface that does not have any visible-to-the-eye grind markings. If I look at the Tormek-honed blade, I see plenty of markings.

David Charlesworth's ruler trick (see his video) is aimed at reducing the amount of steel that one has to remove in order to sharpen to 6000 or 8000 grit. I could not imagine him stopping at 1000 grit and saying "that is good enough". Well, for some it may be good enough, but I would then add, "good enough for what?". Certainly not a smoothly planed surface.

So I would not use a Tormek alone for a plane blade. Preparing it for higher grits, certainly, but not beyond this point.

Regards from Perth

Derek

Originally Posted by silentC

Since 'rouge' is French for red, then you could call it 'vert'
Red Rouge is a tautology

Do you guys have grinders that you can throw into reverse, or do you turn them around?

I turned mine around but the bloody cover gets between the blade and the wheel.

Originally Posted by derekcohen

Arron
There is an issue here, one that has been raised many times on this forum, involving going from wheel to rouge. Basically, the edge you get this way can be sharp but will not be smooth. Sharp is needed for chisels and non-finishing plane blades. Smooth is essential for finishing plane blades. Smooth and sharp gives the easiest cut. Going directly from a wheel leaves too many deep scratches, and it is these that will leave a serrated edge on the blade (feel for it - it will catch). Using a graduated series of sharpening mediums before the green rouge (e.g. 1200 and 6000 waterstones) will remove the scratches and produce a smooth edge for honing (feel it - you cut yourself, and only reallise it later). Using the green rouge directly after the wheel just polished the serrations. So you have sharp serrations.

Having said all that, I am not knocking skipping grits. It just depends what you want to do with the blade.

Regards from Perth

Derek

Interesting stuff Derek. I think I can relate to what your talking about.

But when you refer to 'smooth'. How do you know ? I mean, is a sharp blade with that 'smooth' quality obviously visible without say, a magnifying glass ? In your opinion.

The results I get with my green abrasive to me is obviously the best I could get. Just looking at the mirror reflection you get. Just checked the catalog, and its called chromium oxide. Not aluminium oxide. I don't know the difference, does anyone ? I'd like to know.

What situations I can relate to when I've attempted to buff a ground edge that wasn't ground properly. eg. Instead of a smooth consistant scratched area, it was jagged in parts. And when I buffed that the jagged parts remained , albiet polished. <- ie. a visible inconsistancy. But I suspect your refering to something beyond that, something that your can't see.

Mostly however, the results I get from the green compound (at least the brand I use) is of that smooth/sharp finish you talked about above. Feels smooth, and the results on my stock are definetly polished. This is where I'm confused on your point.

Maybe this Chromium oxide just cuts quicker, in such a way it removes all previous scratches entirely ? I definetly know how careful I have to be with it on my buffing wheels. It really eats through the steel very quickly. And if I'm just buffing a tip, with less area to abrade, its hard to imagine that its not totally removing the previous scratches.

I definetly think sharpening with them is just the bees knees, as long as you use them on edges that are very near burring, or already burred from a grinding process.

The only real problem I have experienced is rounding and the problems it creates for resharpening. I mean, you can buff an edge, use it till it bluntens, take it back and reform your edge maybe once more if your lucky, but after that you have to regrind. Any more buffing just rounds your edge to an angle thats far more than acceptable, an angle that makes it too hard to use.
And I've done it quite a few times. The blade looks fine, obviously sharp, but as soon as I work it on my timber the resistance it gets is obviously to great, something feels wrong. And this often corrisponds with repetitive rebuffing without grinding in between.

So, one has to just get good at regrinding. And do it everytime before buffing. And when one gets the hang of it, it really doesn't take long at all. I'll try and start a thread on it some time to try and properly convey my point. With pictures.

Apricotripper,
I agree with just about everything you have written here (which is a real worry as I have read some of your earlier posts). The green compound cuts quickly and removes what tiny scratches are left by the grinding process. However it does it only to the extreme cutting edge. This necessitates a hollow grind across the entire bevel - as exposing too much steel to the green compound would make the process take too long. It also requires a steady hand and a great deal of concentration to prevent rounding the bevel - which is why I mount the grinder so the wheel rotates horizontally wherein I can monitor the angle at which the blade and wheel meet. Of course some rounding occurs, but it is not significant on the first hone after a grind.

Your point about the grind not being very long lasting is a good one, however. It has occured to me that you would only get a couple of hones before the bevel is rounded by the honing process. I havent had to face this problem yet but it seems to me that the blade would require only about 10-15 seconds on the ultra-fine wheel before honing again - as only a tiny bit of steel need be removed (the hollow grinding guarantees that).

Derek.
I hear your point about the Tormek. I had the same experience with one of those guys demonstrating a multigrind. He couldnt see that the blade was sharp but ragged - even after I pointed it out - so we agreed to differ. I have never used a Tormek, but I wonder whether there is a chance that the problem was the demonstrater, not the machine. Having done some demonstations myself, I know that one is usually focused on getting a result on the table quickly before the audience looses interest on wanders off - if the result is not the best that the device can do it doesnt matter much because most of the audience cant tell the difference anyway. Whatever virtues Tormek's does have, speed is not one of them, so the demonstator would be trying to minimize the time taken to sharpen a blade. No doubt we will hear from some Tormek owners whether their machines really do produce blades with ragged edges.

As for whether the two-grinder method really does produce a 'glass-smooth' planed surface, I guess the only way to prove it is a blind test. I have 2 identical mujingfang smoothers - the Chinese style ebony ones with the short HSS blades. One was labouriously scary-sharpened to 2000 grit and then buffed, used once then not used again. The other I will sharpen using the grinders. I'll set both up, and using the same piece of timber get my wife to tell me which she thinks is smoother (assuming more sensitive fingertips there).

Arron

Hey ya Arron, we're definetly on the same wavelength here. I'm glad somebody else has had similar experiences.

I agree with just about everything you have written here (which is a real worry as I have read some of your earlier posts).

Oh, him, Your getting me mixed up with the OTHER apricotripper. Don't take much notice of him...

The green compound cuts quickly and removes what tiny scratches are left by the grinding process. However it does it only to the extreme cutting edge. This necessitates a hollow grind across the entire bevel - as exposing too much steel to the green compound would make the process take too long.
Yes I agree, on the hollow grounding cancelling out the rounding. It defeats that worry of rounding too much. For paring chisels, and all blades that are been exposed to not much force, I hollow ground as low as 20 degrees. Then just buff the tip. Nice elegent looking edge, and very sharp. As you know.

It also requires a steady hand and a great deal of concentration to prevent rounding the bevel - which is why I mount the grinder so the wheel rotates horizontally wherein I can monitor the angle at which the blade and wheel meet. Of course some rounding occurs, but it is not significant on the first hone after a grind.
I thought about this problem when I first got a hard felt buffing wheel. And thought 'why not make it horizontal ?' . Never got around to setting it up though. I'd be interested in seeing a picture or at least your thoughts on it. I imagine you've learn't some interesting points from buffing horizontally. Good and bad.

Personally, from practise I've found the vertical buffing wheel setup to get easier and easier to use. Initially very daunting I admit. But I've developed a style that makes small blade sharpening, like chisels and the like, very quick, ie. straight from grinder to buffing wheel freehand.
For me, what made all the difference, was setting up the wheels on pully driven workheads, such that they were mounted right on edge of table, so I could have as much of both grinding and buffing wheels overhanging the edge as possible. And no engine housing, like you get with regular grinders, fouling any movement.
With a setup like this I can brace the blade very strongly, with both hands, often with blades handle wedged into my lap. Very steady. But the biggest advantage in this is that from this position with plenty of light you can look straight down onto the edge and follow its change instantly without having to lift blade up for a closer look, thereby loosing track of that previous stance.
For grinding, this means you can watch closely as that flat glinting edge dissappears to a burr. ie. you can ensure you get a consistant burr along entire edge without going too far. Consistantly.
For buffing, being able to sight down the edge means you can ensure you polish only the tip, just how you want it, without rounding the edge.
I'm very proud of this, because it means no guides, no medium stones, and it gets me back to work much faster.

Your point about the grind not being very long lasting is a good one, however. It has occured to me that you would only get a couple of hones before the bevel is rounded by the honing process. I havent had to face this problem yet but it seems to me that the blade would require only about 10-15 seconds on the ultra-fine wheel before honing again - as only a tiny bit of steel need be removed (the hollow grinding guarantees that).

Sound like you may have a better resharpening method here. Or some kind of secret discovery I can often resharpen once or even twice, by going straight to the buffing wheel. But I prefer to not risk it, and just lightly re-form the edge and grind bevel to burr quickly before hitting the buffing wheel.

As for whether the two-grinder method really does produce a 'glass-smooth' planed surface, I guess the only way to prove it is a blind test. I have 2 identical mujingfang smoothers - the Chinese style ebony ones with the short HSS blades. One was labouriously scary-sharpened to 2000 grit and then buffed, used once then not used again. The other I will sharpen using the grinders. I'll set both up, and using the same piece of timber get my wife to tell me which she thinks is smoother (assuming more sensitive fingertips there).
Be interesting to here your results. I suspect however, in practise at least the differences would be minor. IMO. But I like to be surprised

I'll attach some old photos I took,,,,might help show what I've been discribing.,,,used them in previous posts....
picture 1 and 2 - I have a bar fixed above the buffing wheel, for when I want to use a guide. This allows me to re-sharpen anything. In these photos its 6" jointer blades. I usually re-sharpen about 3 sets at a time.
picture 3 - Might be able to see the wheel better in this shot. Shows how I re-sharpen my straight razor (the lightest of touches with this one )
...Of course I hold it better with two hands. I can't really show that because someone has to hold the camera.

Oh , yeh , you might be intersted in the thread 'sharpening wooden moulding plane blades'.
http://www.woodworkforums.ubeaut.com...8&goto=newpost

Spent a whole night setting this thread up. So I might as well show it off. A carving buffing wheel is employed here, with a tool rest for stability. Your into buffing wheels so you might be interested.

Seeya.

An interesting discussion.
It all comes down to how sharp is sharp for you.
The average builders chisel would be considered wonderfuly sharp if it had been done on a tormec. (by the builder) However some in present company would probably like their butter knike with a "more servicable edge".
The tormec does a wonderfull job of getting things good & sharp for the average person.
For a lot of applications that would be adequate. But for serious darksiders I don't think you can compete with some sort of stone, at least in the later gritts. Maybe diamond paste & glass perhaps.

cheers

This is not a criticism of anyone but has anyone actually used the Tormek and done the tests or are the opinions based on what they think would occur.

From 1000 grit on the stone to the leather wheel with paste does what exactly. Does anyone know from experience.

I own a Tormek and I use it along with a buffing wheel. I find the results to be very good indeed. I'm not a darksider but do use and like using my handtools.

I am interested in your opinions as to using a Tormek to best effect. What would you do in addition to what is done after the blade has been sharpened on the Tormek?