Sharpening stones for planes and chisels

[Claus]

Most of my plane and chisel edges are in pretty good shape. The quality runs from Aldi specials to Hock replacement blades. I’m pretty much a “less is more” type and have been touching up the edges as needed and that works pretty well. I currently use two DMT diamond stones, a D8F (600) and a D8E (1200), and a strop with green compound.

I’d like to find something appropriately coarser for heavier work, as in changing bevel angles or adding a camber to a plane blade. So what would be a suggested coarser stone or 2 to help me in that direction? DMT D8C (325)?

On the other side- could I get a sharper edge with something finer? I’d like some suggestions for that.

I’m pretty happy with the diamond stones as they’re not as messy as oil or water stones (I don’t have running water in my shop) But I know they my be limited. I also have a grinder but I’m not sure of the grit of the wheels and have been a reluctant to use it, but appropriate wheel suggestions would also be appreciated.

Thanks everyone

 

[Mike Davis]

I have a 325 and use it for used planes that I refurbish as the initial hone.
For major changes I use the grinder.
My son has surpassed me in sharpening and teaches butchers to sharpen knives.
He uses a hard Arkansas oil stone for the final finish. I think he has a green and a black.
Yeah, they are super expensive.

On my grinder I use CBN 180 grit for rough work and 600 grit for touching up my turning tools.

 

[mdbuntyn]

I have a 220 DMT and often wish that it were coarser (based on the recommendations of some guys that I know, my next diamond stone will be an Atoma), but the bulk of my sharpening is done on soft and hard black Arkansas stones.

If you're getting the results that you want with the 1200 and green compound, there's no need to add anything.

Consider buying a copy of Sharpen This, by Chris Schwarz before changing anything

Sharpen This (signed by the author + PG-13 Sticker)

You can download an excerpt of this book here. by Christopher Schwarz Sharpening is not a sport. If you want to be a better woodworker, you need to learn to sharpen. If you want to be a better sharpener, you need to stop paying so much attention to tertiary bevels and carbide formations in steel...

lostartpress.com

 

[Graywolf]

I think you are set on your stones presently. I need to know if your grinder is a slow speed or a high speed. I use a slow speed grinder with 80 grit wheel that I use for my general grinding work, ie changing angles, grinding due to damage or jut refreshing the edge. From there I use stones. I also use two hand cranked grinder with 60grit wheels for the same application.

 

[Scott H]

I would recommend using the grinder for anything where it's taking too long on the stones you have, and see how that goes. I think that now that I have gotten used to using mine, I appreciate more that they are kind of a necessary tool for rehabbing/changing tools significantly if you don't want to spend hours rubbing steel on stones.

That being said, when I am reprofiling a tool, I do go from the grinder to a DMT extra-coarse, DMT coarse, DMT extra-fine, 2000 grit norton sandpaper on glass, then strop.

I suspect your grinder may already have a pretty low grit wheel mounted on it that should be fine for what you need. Lower grit for grinding is better the way I use it because it means you are spending less time at the grinder and the lower grits cut cooler.

What I have, and it's not at all a necessity, I think, is an 80 grit Spartan CBN wheel from Woodturner's Wonders, on a slow speed Rikon grinder. I got the self-aligning washer kit and stuff. Just to be brief, I found I really like the CBN even though it is more expensive -- perfectly balanced/almost no vibration, always stays the same diameter which is convenient for jigs, grinds cool, zero stone dust in the air/shop floor, cannot have cracks in it. The downside is cost and that they are really intended for grinding hardened steel, and softer metals must be ground very sparingly or not at all, or else you can clog them. I'm not an expert on care instructions for that since I still mostly only use it only for hardened steel, I spoke to Ken (I think) from Woodturner's Wonders on the phone about it but it has been a long time.

The only thing I miss sometimes is I wish I had gotten a CBN wheel that had grit on the sides so I could sharpen flats and not just hollow grinds.

 

[tvrgeek]

I do primary now on a 180 CBM wheel on my low speed grinder. Took a little practice but now I can get good strait grinds.
Then off to my DMT/Shapton stones. Really, the diamond is only to give that perfect strait edge ( Veritas gig) as if I am good enough on the grinder, a 6000 Shapton will get that fine secondary, and then the 16000, though I am beginning to doubt the 16000 is much of an advantage. Strop with .5 micron green. Note HUGE differences in stroping compounds. I get mine from Taylor. Some green is over 30 micron.

I also have the round corner, side grit wheel. Pay the price to WTW and you won;t regret it in the long run. Same with the Wolverine jigs.

I keep my old cheap 6 inch grinder with Norton wheels for softer metals. CBN is for hard steels only.

 

[Rwe2156]

IMO you definitely need to go higher if the edge you're getting seems less than adequate. If you're used to a certain degree of sharpness, you won't know the difference until you try a higher grit. And trust me you will see a difference.

Personally I prefer X coarse diamond plates when I need radical material removal. But under normal conditions you should never need to go below 800 diamond to re-hone. If you need to go to 600 you've gone past the due date and if you're at 320 you're in the area of rehabilitating a damaged edge.

But this is one of those "if it works for you" things. I don't think 1200 is high enough - but that's me. I jump from my 1250 DMT to 8000 water for chisels and plane irons. I will go to 16000 on plane irons for certain grain situations. You don't need expensive water stones. I use a Norton 4000/8000.

I also hollow grind chisels and plane irons and sharpen to a 2° or 3° bevel. This isn't as important using a jig, but I think it makes a big difference free hand.

Stropping is OK, but IMO is not a substitute for stopping at a lower grit. I've read of people going to 1000 and stropping like 75 strokes, which makes no sense to me. If you do strop I strongly recommend using MDF not leather b/c I'm a believer in the dubbing effect with leather strops.

 

[tvrgeek]

I have been testing with my Bess measurement jig. I can go to 16000 on a plane iron, but a couple of swipes with a plane I am at about the same as 8000. Bench chisel and paring soft wood, no substitute for sharp.
Strop on MDF, leather, cardboard, or my palm. Depends on the tool.

 

[Scott H]

When talking about high grits I find it's kind of essential to look at the Grand Logarithmic Grit Chart for the particular stone you are looking at buying because the standards vary so widely. Depending on the standard "8000" might mean anywhere between 3 and 1 micron for example and that's not even a particularly extreme case.

I buy a particular kind of Norton sandpaper that bridges between my DMT 1200 and the strop and it does not say the standard on the package and I have called Norton twice over several years and they have given me 2 different answers, but I know it's in between my DMT 1200 extra-fine and the strop I use, and it gives me a better edge.

 

[Scott H]

Strop with .5 micron green. Note HUGE differences in stroping compounds. I get mine from Taylor. Some green is over 30 micron.

Seconding this. One of my "a-ha" moments when I was figuring out sharpening to start was that my green compound is not the same as some random youtuber's green compound.

"Green is not a particle size" is how I like to phrase that particular revelation.

 

[tvrgeek]

To make it worse, a given particle size does not directly translate to it's ability to cut. Edges get knocked off.

 

[Gofor]

There is a YouTube channel: OUTDOOR55, that has some good takes. Geared more to knives than plane tools, but most still apply. He does a lot of macro-photography that shows the results of different techniques, compounds, etc. on the edge.

 

[tvrgeek]

I go by measurement. BESS standard. The edge profile you want for a knife is a little different. The roundness from a softer strop is often advantageous. Kitchen knives a little thinner and a flat single bevel is best. Smooth steel required of course. No grooved, diamond or ceramic.

Purpleheart is a real pain, that's for sure. Trying to make a frame coping saw with some. Brittle.

THere is ONE correct way to sharpen. The one that works for you. Sharp does not car how it got that way.

 

[tvrgeek]

Might also look at WoodcraftBySuman

 

[Bill Anderson]

I think you are set on your stones presently. I need to know if your grinder is a slow speed or a high speed. I use a slow speed grinder with 80 grit wheel that I use for my general grinding work, ie changing angles, grinding due to damage or jut refreshing the edge. From there I use stones. I also use two hand cranked grinder with 60grit wheels for the same application.

Sharpening is a grind! Break down your system into four steps: flattening, fast and furious, shaping, and fine tuning (!). The very first step always is to make sure that the face (non bevel side) is flat and smooth, no defects. The whole face does not need to be completely flat, but the leading edge and the two sides should be planar. There may be a hollow in the center, dealt with in future years. I use a Worksharp or a belt sander to prep the face, then use a fine oil stone to get it to a mirror finish. After that, it’s the bevel. First, for me is a slow speed grinder, with a very friable wheel, maybe 60 grit up to 120. I use those blue zirconia wheels. I modified my tool rest (it’s a Veritas articulated one) with a wrap around platform (plastic) attached to the Veritas with double stick tape. Never grind to the cutting edge! Dress your wheel frequently with a diamond dresser of some sort to keep the wheel clean and flat. The goal is to get the tool into the ballpark. If you use cambered irons, this is the place to shape that. I rough grind the bevel to be (by eye) 2-2.5 times as long as the thickness of the blade at that point. This comes out to be 25-30 degrees or so. An excellent bevel angle in general. The second step, once the overall shape of the edge is established, is to work on the bevel. I use either my worksharp or a diamond stone, or a medium oil stone. Any of those will work well. The goal is to establish two faces on the bevel, one at the leading edge and one at the heel. Not to eliminate the curve of the bevel, but to establish two flats you can easily find when hand honing the edge. Again, I do not go right to the edge, but so close that I have to hold it up to the light and peer at it to see the cutting edge. Finally, I hand hone the bevel with a fine diamond or water or oil stone, focusing on keeping the bevel from rocking. I check frequently with my fingertips to feel if the leading edge is curling up to the face. That tells you that you have reached (and gone just a bit beyond) the cutting edge. After that, you hone the face and the bevel together back and forth until you can feel a smooth even cutting edge with a light drag of your fingertip.

 

[Claus]

Thanks everyone for some very useful information. My takeaways from this discussion -

-I did get a coarser 325 diamond stone, basically to set up my tools to consistent bevel angles.

-I’ll probably avoid the grinder for now. I’m not really into rehabbing tools, just try not to bring home any that need too much work. But there’s good information here if I decide to revisit the issue.

-I did get a piece of “numbered” stropping compound, gonna toss the generic cheap green crayon

I’m still seduced by that “just a little sharper” siren and will probably go to an 8000 grit stone at the top end. Thinking about the DMT D8EE extra extra fine diamond stone. Does anyone have any experience or opinions about this?

 

[mdbuntyn]

Thinking about the DMT D8EE extra extra fine diamond stone

I have one, but I never liked it. I prefer my Hard Black Arkansas stone (and the mystery grit green compound that I used to use), even though it's not as fine.

 

[Martin Roper]