Sharpening woes

[Ranala]

So I slowly started picking up my bow making efforts and instantly remembered my annoyance with sharpening. I sometimes get a good edge, and only with one of those honing guides that only work properly on my big chisel. I did a lot of reading on here and one recurring theme is to first do a hollow grind, and then hone. It makes a lot of sense, since there is no way to get a concave face on the bevel, so honing should be easier.

Ok, so I am now looking for a grinder, and I stumbled upon quite some posts here that use a hand-crank grinder. I am probably moving in half a year so I don’t want to invest too much in a grinder, and I found a relatively cheap hand grinder (75USD), but before I go and buy it I would like your opinion on it. Is it really that easy as people around here make me believe it is? Should I go for an electric grinder/tormek (which would be significantly more expensive)? Or should I just stick with stones and get better at using them?

I know sharpening is an important part, but I feel like I am spending 50% of my time sharpening my tools instead of working with them (and sharpening is not really my hobby).

[M Alpert]

I personally don't see how you can ever get sharp blades without some kind of grinder. What kind, there are many opinions... but only with stones, you will only get frustrated!

Get a grinder and learn to make it work for you. There are many different methods. Personally I think a cheap bench grinder with a custom-made adjustable table and a better wheel is probably the cheapest and most versatile option. 

I have tried Tormek (expensive, and also must be learned), and a hand grinder (how do get a good result with one hand, while the other turns the crank?) My favorite is the Stephan from Germany (flat, see-through discs), but they are expensive, if you can even find them.

[Shunyata]

Grinding should be a one time setup exercise.  An inexpensive tool grinder works fine for this.  I never understand when people describe grinding as part of routine maintenance.

If you can’t reliably get an edge the problem is probably with your honing technique… you can get a good edge on a wide range of grinds.  
 

The problem can also be low quality steel.  It is very difficult to form a good edge on bad steel (or sometimes very easy, but it only lasts 30 seconds).

Japanese laminated steel is difficult to set up, but honestly to an incredible long- lasting edge.

[Dennis J]

Hollow grinding is a quick way to establish a low or high angle bevel on a chisel, gouge or plane blade and it makes sharpening easier, especially with very hard carbon steel or powdered metal blades like the PMV11 ones.

I have an 8 inch aluminium oxide dry grinder with a tool rest to make initial hollow bevels which runs at 1725 r.p.m. I have to be very careful using it with thin plane blades to avoid overheating. I also have an 8 inch water drip grinder which I use freehand, no rest,  to establish a primary bevel on chisels and gouges which need a lot of attention. I simply hold them horizontally to the wheel which results in a flat bevel surface.

In the case of gouges that hollow grind disappears after a few sharpenings. When it becomes harder to resharpen without increasing the honing angle I go to a very coarse water stone to grind back the whole bevel and a little hollow grinding using the wet grinder can speed up that operation.

I only use a honing guide to sharpen plane blades on steel plates charged with diamond paste after a very careful hollow grind using a tool rest on the dry grinder. After repeated sharpening of course the hollow grind will disappear. And using steel plates with diamond paste works well on narrow bevels but not wide ones so it becomes necessary to go back to the grinder.

With a good set of water stones and a little help from a low speed grinder sharpening chisels and gouges is not hard if you use a routine that works.

There are plenty of videos showing the Japanese using these without powered grinders. However, I think that they don't approach sharpening plane and chisel blades in terms of  primary and sharpening bevels. The reason for this is that they use thick laminated blades with soft iron backing. So they usually regrind  the whole bevel starting with coarse water stones. Once some of the soft iron backing is ground back the thin high carbon steel at the edge can be sharpened with finer stones. 

[Shunyata]

For Japanese chisels (and also plane blades) that are laminated steel and hollow ground on the flat, a different procedure entirely is used.

Rather than grinding away the hard steel layers and changing the geometry of the edge, an uradashi cold working procedure is used to reshape the edge and reestablish the hollow.  Then regular stones are used to clean up the flat and edge.

Uradashi is scary.  It’s easy to shatter the blade if you aren’t careful.  And you need to pay close attention to develop a refined uri shape rather than a deformed monstrosity.  But Japanese blades are worth the effort!

[Mark Norfleet]

8 hours ago, Shunyata said:

Rather than grinding away the hard steel layers and changing the geometry of the edge, an uradashi cold working procedure is used to reshape the edge and reestablish the hollow.

My Japanese chisels have served me well for at least 45 years using careful grinding and honing, rather than “cold working” them with a hammer.

[Shunyata]

57 minutes ago, Mark Norfleet said:

My Japanese chisels have served me well for at least 45 years using careful grinding and honing, rather than “cold working” them with a hammer.

Interesting.  You are using oire nomi chisels?
 

What do you do when the sharpened edge eats into the uri hollow on the flat?  Grind down the flat to remove the divot and regrind the hollow?

[Mark Norfleet]

47 minutes ago, Shunyata said:

Interesting.  You are using oire nomi chisels?
 

What do you do when the sharpened edge eats into the uri hollow on the flat?  Grind down the flat to remove the divot and regrind the hollow?

Yes.

It doesn’t.  My normal honing routine maintains the flat surface and I don’t know that I’ve ever had to regrind a hollow.  I do bias the pressure towards the cutting edge when I’m honing.

[Michael Darnton]

I use a soft white stone and a good Veritas guide on a hand grinder. When the hollow starts to go away I go back to the grinder and re cut the hollow without touching the edge, so there's no mess to clean up. Consequently I'm usually only using an 8000 grit stone.

Sure, there's a learning curve to cranking with one hand and guiding a tool with the other, but that's what learning all new tool using skills ais about, and I don't notice any more.

[Chamber]

I feel your pain with this. I found UNH Violin Institute sharpening class very helpful and second the Tormek and Veritas guides. 
Wen makes a Tormek dupe 6” wet grinder with guides that is currently budget priced at $127. They also have a larger one.
It could bridge the gap until Tormek makes sense.  I have used it and with adjustments found it very helpful.  

WEN BG625V 2.5-Amp 6-Inch Variable Speed Bench Grinder

[Shunyata]

10 hours ago, Mark Norfleet said:

It doesn’t.  My normal honing routine maintains the flat surface and I don’t know that I’ve ever had to regrind a hollow.  I do bias the pressure towards the cutting edge when I’m honing.

I’d like to hear more about your normal routine.

Traditional sharpening wears these chisels down so that the hollow moves into the edge… like the top chisel below.  This is because traditional sharpening avoids grinding down the flat.

The traditional way to fix this is uridashi… sometimes called tapping out.

[edi malinaric]

Hi All - don't need no grinder .... https://brentbeach.ca/Sharpen/jigarch.html#userjigs

cheers edi

 

[Ranala]

Thanks all, I'll be buying a hand grinder, and will try to learn how to use it properly (I have some junk chisels here that I can practice on before my proper chisels).

Is it right to assume that a 6" grinder is enough? No need to go for an 8" right?

[Michael Darnton]

6" is fine. Make sure it's complete and that one of the feet that goes on top of the bench opposing the screw isn't broken off--that's especially common. You don't need the tool rest that is probably missing from it.  Prices on ebay seem to have dropped a lot.

Generally the old ones are better, but there's a new one on ebay for $42 that almost has me tempted.

You'll discover that the shaft is too small for modern stones. I just start winding on masking tape until I get a tight fit to the smallest size you can buy a reducing collar for, about 1/2"--the stone may come with that.

[Ranala]

1 hour ago, Michael Darnton said:

6" is fine. Make sure it's complete and that one of the feet that goes on top of the bench opposing the screw isn't broken off--that's especially common. You don't need the tool rest that is probably missing from it.  Prices on ebay seem to have dropped a lot.

Generally the old ones are better, but there's a new one on ebay for $42 that almost has me tempted.

You'll discover that the shaft is too small for modern stones. I just start winding on masking tape until I get a tight fit to the smallest size you can buy a reducing collar for, about 1/2"--the stone may come with that.

Yeah, I think I'll buy one locally here. Had some contact with the shop and they seemed knowledgeable and supply the grinder with a custom made bushing for the shaft.

Concerning the tool rest it indeed does not come with one. Should I make something myself? Or buy something like the veritas tool rest (or some knock-off)? I was thinking of 3d-printing some tool rest/fabricating something from wood.

[Mark Norfleet]

The versatile tool rests Michael has posted about, which are available on amazon, are a good value.

https://a.co/d/hXSDCel

 

[Mark Norfleet]

17 hours ago, Shunyata said:

I’d like to hear more about your normal routine.

I hone the flat and the bevel each time I sharpen.  If the hollow on the broad flat side of the chisel gets close to the edge, I hone some more.  It’s pretty simple.

[Claudio Rampini]

I'm very happy with the DMT diamond stones, coarse and extra coarse, because it gives me an easier and more controllable way to make the bevel, manually. After that I'm using an old german synthetic stone, maybe 800/3000, then I refine the edge with a natural "pietra di Candia", you can see the results in the attached pictures on a small japanese damascus knife. The most important is starting with a good bevel, and you don't have to do the bevel again everytime you have to sharpen a blade, normally it requires about 10 minutes to sharpen a blade in this way. I learned my lesson using the straight razors many years ago, using manually the natural stones, but the diamond stone did the difference making new bevels on chisels, knives, plane blades, gouges etc.