Violin Forum/Message Board

[ctviolin]

What an interesting thing it is.

I've been doing this for over twenty years now. And my sharpening abilities and skills have travelled along with me - also changing along the way

I'm still learning things about metal and sharpening...

I believe I would like to know roughly what other craftsmen think about the subject and perhaps trade methods.

Anyone?
_________________
Look,
Listen,
Learn.

[actonern]

Not to be too judgemental, but I personally find a lot of fetishism in the whole area... guys with 8000 grit water stones and little mechanical angle holders that precisely maintain a 30 degree angle (29 would be a disaster!)...

For some applications, (like a jointer blade that really should be flat across it's face) careful sharpening is essential, but I'd rather not waste a lot of time with this otherwise. I have 2 oil stones of different grit and a leather strop glued on to a 4 by 13 inch board (charged with Lee Valley "green compound."

Nothing against water stones, but I find them soft and groove prone and in need of frequent dressing and messy and I learned what I do from my cabinet making father, so it's easier to keep doing the same thing!

One related skill I think many of us could learn better is the proper technique of sharpening scrapers and then turning a hook. This is a "feel" related skill and until one uses a properly set up scraper it's hard to really know how amazing a tool they are.

[kjb]

I have tried some different things, and in the last year I have finally gotten nice results with scrapers , knives , chisels, still not great with gouges .

tried water stones, glass, sandpaper, and they are great systems. but for now

I ended up with the worksharp, for the purpose of gettting the angle even and aligned , but ended up adapting it for final polish, using different polishing grits and sandpaper and ending up with chromium oxide on mfd disc that I make myself.

this is what is working for me now and I think over time I will expand and try to do different things.

here is what got me started on it.
http://stumpynubs.blogspot.com/2011/12/stumpy-turns-his-work-sharp-3000-into.html

[wm_crash]

If 30 degrees is what you want, 30.1 is off the mark My experience with sharpening has been fairly short (I say less than 3 years) but I tried out a lot of things and can't say there is one that I dislike, but there are some that I prefer over others.

I enjoy sharpening. I find a good sharp edge in itself can be called an achievement even if that edge won't need to cut anything ever; as opposed to utilitarian sharpeners who just need a sharp enough edge to get going with other stuff.

With that in mind, here's a few random points that have stuck to me:

Jigs and tricks:

- For square edge tools, it is faster to learn the quirks of a jig than it it to learn the quirks of your body. Unless you are willing to put the time to learn freehand sharpening, a jig is the way to go. A jig isn't perfect, but it it will have very consistent deviations from perfect. You can measure those, and correct your use of the jig. I have the Lee Valley MKII. I know that this jig will give me a 4 thous out of square over 1" of edge. I account for that by leaning slightly more on the left side. You learn that 4 thous per inch is not a big deal for regular planes, but it sure is for shoulder planes. The cheapo jig that everyone sells for $8 to $15 doesn't let you select specific angles, but the narrow wheel guide will allow you to follow the manufacturer's bevel without introducing out-of-squareness.

- If you have japanese planes, and can't freehand, the "Veritas® Sharpening System" from Lee Valley is your solution. Japanese blades have a very wide bevel which registers easily on the stone. There is a trick to it though. Because of the way they are forged (a very thin very hard piece laminated to thick soft wrought iron), the leading edge gets sharpened a lot slower than the back of the bevel. If you are too relax, the blade will tip back and you will round the bevel instead of sharpening the leading edge.

- The jigs are causing waterstones to go out of flat. The guide wheel simply takes the abrasive slurry and rolls it into your stone crating even more abrasive slurry. Try to back the pressure off of the rolling guide. If that is not possible, sharpen under a very slowly dripping faucet so that the slurry gets washed away. This is mostly an issue on low grit waterstones, (under 1000 grit I would do this)

- I hate the ruler trick. As much as I like David Charlesworth and his work (best dovetail cutting instructor ever), I think the ruler trick is just a bandaid for potential imperfections on the back of a blade. If there is something wrong with the back of the blade, it needs to be fixed, not patched.

Waterstone vs diamonds vs. japanese naturals

- The brand new water stones that you just bought are severely out of flat. Get that DMT Dia-Flat and work on them.

- The brand new diamond stones you just bought are severely aggressive. Use the back of a chisel to break them in.

- The brand new japanese naturals you just bought cost you a pretty penny, and they are pretty.

- I prefer waterstones. I use mostly Nortons with a few add on stones to fill some grit gaps.The Norton 220 is a crappy stone that needs flattening very often. I don't mind that, but it will be replaced with a different stone when it wears out. An 80 grit stone has its place in my arsenal. I rehabbed a lot of old stanley planes and some blades were severely pitted. I don't have a grinder and won't buy one, so this stone is as close as I can get to a grinder (except they came out with a 60 grit stone in the mean time which would be closer to a grinder)

- Going to the highest grit you can isn't just about a sharper blade, but also a longer lasting edge. The way an edge dulls is via microscopic folds in the cutting edge that eventually break off. These folds are smaller if the scratches are less shallow. There are a lot of arguments about this, and I am not going to try to explain other than via my own experience: taking a blade to 16K and then stropping it on 0.5 micron compound will make it last longer.

- There is a story that japanese stones will help an edge last longer because of the nature of the sharpening particles. (Supposedly) The particles in artificial stones are very sharp and cut V shaped grooves. The natural stones give off round abrasive particles which leave u shaped scratches. The U shaped scratches are less prone to micro breakage and hence the edge lasts longer

- Diamond stones are perfect for the person who doesn't want to deal with the patience, the attention, the jeweler's loupe, the zen, the fun, and the art of sharpening. They will get the job done, need no flattening. However, they need cleanings. Because waterstones are cleaned off with a flattener, the metal swarf is removed. On the diamond stones, it needs to be actively removed (a 50:50 solution of simple green works well) otherwise it will cause rust. The biggest drawback on diamond stones is that DMT has a rather big grit jump from 1200 to 8000. On a normal day, there is no stone in between. On special occasions, they have the medium-extra-fine which is a 4000 grit.

- I know nothing about oil stones, and that is one thing I just won't get into

Tormek and vises

- I won't say much about this, but it's saved me trying to sharpen round profile blades. From the #40 blade to the half round profiles. I am planning to use a round profile plane to shape the sides of a frog. The SVD-110 jig is perfect for this. The alternative for profiled blades is to chuck them in a vise and use a small hand held things: slipstones or diamond cards or other diamond little things that DMT makes. Things get really crazy when you try to sharpen a half round skew blade and in that case, a vise and a slipstone are magic.

The steels

- Really really old stanley blades are really really soft, but take a killer edge. I believe the steel is some flavor of M2, but don't quote me on that

- Most western tools are made of O1 (or high carbon) and A2 steels. It's commonly accepted that O1 gets sharper than A2, but the edge retention of O1 isn't as great as that of A2. To put that in perspective, (in my experience ) there is no point in sharpening A2 beyond 8K. I've had people disagree with me on that. But I feel there is no more edge refinement beyond 8K. For the O1, there is edge refinement even at half micron strop (equivalent of a 30K grit)

- Lee Valley has the brand new magic steel called PMV-11. It's supposed to have the sharpness of O1 and the edge retention of A2. I don't know anyone that's had first hand experience with it.

- High speed steel is rough on your stones, use diamonds for that

- Japanese steels come in 3 main flavors: white steel, blue steel, and bought this off eBay and I have no idea what it is. Most of my japanese tools are off of eBay. White steel behaves like O1, blue steel behaves like A2. Apparently with experience and with exposure to known steels, you can determine unknown steels by the way they sharpen. I am not there.

Little secrets that nobody else knows:

- Hock plane blades are sharp on all sides; I cut myself with the sides while holding one while sharpening

- The burr on japanese steels isn't as readily felt as on western steels

- I am not able to feel the burr on Narex chisels - which is a chrome vanadium steel

- My sharpening sink bridge is a piece of 2x4

- The Nubatama Extra Extra Hard 1K stone is the best 1K stone I've ever seen

- Flattening stones with sandpaper is a mess you don't want to deal with - use a (very expensive but worth every penny) Dia-Flat, or a less expensive DMT Coarse 8" x 3"

- The pencil trick for stone flattening is misleading. Just wipe the water off the stone and use the ruler of a combination square to check for flatness

- Make sure you break the edges on your waterstone, else you will cut yourself while sharpening

- Always knock the burr off on a very high grit stone, certainly higher than the stone that has created it

cheers,
wm_crash, the friendly hooligan

[John Cadd]

For gouges the final edge can be polished using Solvol Autosol chromium polish on some pine wood or any softwood .Cut a groove in the wood first , no matter how blunt your gouge is . About 4 or 5 inches long. Clamp the wood in a vice first . Rub some chromium paste in the groove. Then draw the blade backwards in the groove. Rotate the gouge as you move it backwards . As the edge becomes sharper you can improve the original groove in the wood renew the paste. You can feel when it`s more shiny and sharp as there is less drag .This gives a clean edge without the whisker hanging on . This works for any shape blade but is most useful for the curved gouges . There are two grades of Solvol now. The most agressive type may be best .

[Mikes]

I use a variable speed 6" grinder with a gray stone wheel on one side (not sure of all the specs but nothing fancy) and a buffing wheel on the other side and the stock tool rest. Then I use a 1200 water stone and a 6000. All chisels, knives and plane blades get only sharpened on the water stones (unless I need to regind). Gouges get honed on the 1200 stone and then polished on the buffing wheel at highest speed using a yellow compound. I've been a furniture maker for years and learning how to sharpen is all in a days work. The past few years I have attended the UNH summer program for violin repair and I'm always amazed how difficult a time people have with sharpening.
Best,
Mike Spencer

[kjb]

well I guess its one of those things that when you get it, it seems simpler?

[Michael Darnton]

I go directly from a coarse white wheel on a hand grinder to an 8000-grit King Gold stone, for virtually everything. Since you're only polishing the tiniest bit at the edge, it's extremely fast. The condition of anything behind the couple of molecules at the front that do the cutting doesn't matter, so why buff it up? When the polished part of the bevel grows too big, I set the grinder carefully to take out the middle of the bevel and grind the hollow back out to the tip and heel of the bevel again, but try not to cut through to the very tip with the grinder--that way there's even less work to it on the 8000 stone. I was surprised recently to discover that this is the way straight razors are made--unbelievably hollow and ground flat (edge and spine down on the stone) on the very finest stones, but the bevel never grows beyond about .5mm in width. They can be maintained just about forever on a 12K stone unless you do something stupid to the edge.

On tools that require a slight rounded relief for cutting curves (many gouges, my small knives for carving the interior cuts of bridges) I'm simply more casual with my 8000 stone, which rounds the tip bevel slightly enough to work. For things that require clean straight cuts (plane blades, my soundpost knife) I'm careful about the 8000 step, but hardly any care is required, just a lack of carelessness.

I use the 8000 stone for the backs of plane blades, etc. but have the backs of most of such tools hollowed out a bit, Japanese style, so all of the bearing is on the edges and tip of the steel. For the insides of gouges I have a felt wheel on a hand grinder.

I have a 1000 grit stone, and never use it for anything.

I find that when the tools are sharpened particular to the work they have to do, they work better.

Straight razor grinds. Most modern blades are around V to XII in hollowness:


_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[fjodor]

Cool. I never knew how a straight razor was ground before i bought an old E A Berg on a swap meet. (The seller offered it for free if I shaved off my beard) I would say the grind on that blade was something like 2-5 on the picture.
Since then I destroyed the razor and made a small knife of it. The rest of the blade I used a small finishing scraper it's easy to sharpen on a wetstone because of the hollow grind.

[ctviolin]

I use a 1" belt sander with a couple different of grit 1" belts for basic grinding the metal ("grinding" meaning; cleaning up the edge), and then a 1" leather belt for finish stropping with a bar of stropping compound - for putting that razor edge on the tool.

It has three wheels on it in order to run the 30" belt around 3 different turns, and this is where I'll put the initial edge on the tool with one or two grits of "sandpaper", then it's on to the leather strop and a bar of compound. So I can always sand with the belt traveling AWAY from the blades edge.
And - I can use a wheel for a straight hard surface or between the wheels for a surface that gives...

An example of what works best for most finish edges is a worn 600 grit belt, for example; as it puts an extremely fine edge on just about anything as it will act like a 5-6000 grit stone.
It's quick and I have a light right there so I can see the edge develop and the wire edge form. It (the round wheel(s) )put a slight hollow ground on everything I sharpen there - and an extremely sharp edge is not difficult to obtain with this setup - very quickly.

Gouges are extremely easy to get sharpened well - which used to be a tad difficult for me.

On plane blades I prefer the scary sharp method, and I have a 4" X 14" piece of tempered plate glass in a wooden holder that can be clamped to the workbench and whatever grit paper one needs can be (I use spray mount) put on the plate glass and ground with a simple sharpening jig.

This does indeed work a scary sharp edge quickly.

The interesting thing is that for years sharp enough was sharp enough for me. As I get older and want to use less muscle and more edge to get the job done - this method seems to give me any degree of edge I need quickly and repetitively.
_________________
Look,
Listen,
Learn.

[Mikes]

[kjb]

no not at all, I was just commenting for others who are just starting out, and I know from experience you can get pretty frustrated till you start getting some good results. thanks for the information and your insight. kevin

[Andres Sender]

It's worth noting that Michael Darnton's wonderfully efficient sharpening method works just fine on M3 HSS, so no diamond stone is necessary. M2 incidentally is another HSS, with similar properties and hardness to M3. Back in the old days, Stanley Australia famously provided plane blades made from HSS, purportedly to cope with the insanely hard local woods down there. I am not aware that such blades were sold in the US.
_________________
You can only connect the dots that you have.

[ctviolin]

[Cliff Green]

Michael, do you use a guide or modified tool rest to aid in accuracy on your hand crank stone? I tried using a hand crank and the basic tool rest and found difficulty keeping the edge straight and square, especially plane blades.

Presently I use water stones and a honing guide by Veritas. The Veritas guide has a long roller which mitigates grooving the stones. I also have a horizontal plate water stone sharpener made by delta, which was relatively inexpensive, for reshaping using 250 and 1000 grit round plates.
One other handy tool is a small variable speed grinder with felt wheels charged with abrasive paste. I only use this for blades that can be used with slightly rounded edges such as gouges. A quick 2 or three second polish after even 10 or 15 gouge strokes makes rough gouging noticeably easier. I rotated the motor 180 degrees on the base so that the wheels spin away from me when working from the switch side. Very important!