# How long should a plane blade stay sharp?



## Stevebo (Nov 11, 2014)

How long do you expect a plane blade to stay sharp for?

I ask as I can get my blades razor sharp, and for a little while I'm very happy with the wood surface that results, but it seems the blade dulls fairly quickly. 

After smoothing out a piece ~6" x 2' the blade isn't 'razor sharp' anymore - i.e. it won't take hairs off my arm, and after smoothing out a second piece the surface finish starts to be less than ideal.

I'm going for a smoothing plane finish so this is leading to a lot of re-sharpening.

The plane in question is an old Craftsman by Millers Falls with a 30 degree bevel and the wood is cherry.

A related question:

What grit do you start with when re-sharpening a blade? Do you just sharpen with the last used grit - i.e. if you sharpen to 2000 grit do you use that to re-hone the edge or do you go back a bit?


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## woodnthings (Jan 24, 2009)

*your blade angle may be too acute*

You could try a micro bevel to reduce the angle a bit. It will make the sharpness last longer. 
The steel in that blade may be a lower grade, but that's had to determine. I have an old Miller's Falls plane and it work fine the few time I have used it. 
I use the diamond stone to hone it after sharpening on a belt grinder when it becomes dinged. I am not a hand tool guru, so my standards may not be up to par. :blink:


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## Dovetails (Jun 8, 2014)

It's more complicated than that. I would suggest sharpening it and trying again. I would take a strong look at your technique before you chase the wormhole of upgrading blades or setting up different angles. Make sure your sharpening technique is solid. Paul sellers does a good job of explaining his method, as does Rob Cosman his.

If I touch up a blade, I hit it with the Fine, and then extra fine DMT, then the strop. I Spend 30 seconds on it.


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## epicfail48 (Mar 27, 2014)

Until its dull.

All sarcasm aside, that's a fairly subjective question to answer. There's so many variables, e.g sharpening angle, steel type and temper, hardness of the wood, that it's hard to give particular answer. You could take 2 blades, sharpen both the exact same way, use them the exact same!e way and one will still need sharpening before the other

As far as resharpening goes, it depends. If the edge still has some sharpness and just isn't razor sharp, I'd hit it with whatever the highest grit you sharpen to, 2000 grit sandpaper in my case. There eventually comes a point where that won't revive it enough, and I'll drop down to 400 grit before working back up


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## Nick Sandmann (Oct 24, 2014)

Until it's getting too hard to push or you're getting tear out. I've never tested, but I'm guessing the "shave with the blade" stage doesn't last too long. The question is how well it's working on the wood, not on your face(or hand).

Also depends on what you're planing. Cherry shouldn't be too hard on a plane, but if you're planing through a lot of knots, that will definitely dull a blade quickly. Also, if you're shooting end grain, that will typically dull my blades a lot faster than planing face grain.

First thing I'd look at here is your sharpening. Is the back of the blade flat and polished? The whole back doesn't need to be polished, just up by the cutting edge(an inch or 2 would be fine).

Next, what are you sharpening with? You mentioned 2,000 grit. For smoothing plane sharp I sharpen up to 8,000 grit and would be worried if you weren't getting to at least 4,000 - 6,000 on that blade(both on the bevel and that polished back).

Next, are you using a honing guide to sharpen? If not, get one.

Finally, if everything else previously listed is being done, I would turn my attention to the plane iron. What kind of steel is in it? Might be worth buying a hock, lee valley, or other after market plane blade and cap iron and see what kind of results you get(I'd focus on sharpening before the steel though).


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## Nick Sandmann (Oct 24, 2014)

also, once it's dull. I start back on my 1,200 grit stone and work my way up. 

Unless I put a huge knick(hit a nail, dropped it on the floor, etc...) in the blade, in which case I'll re-grind the primary bevel and then hit my stones.


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## ShepherdCinder (Aug 12, 2014)

*Step 1 - Preparing the Back Face*


The back face on a correctly sharpened blade has two characteristics: it is flat, and it is polished. Preparing the back face is a one-time operation. The back face can only be made flat if the abrasive surface is flat. Polishing is the removal of the grinding marks until the surface becomes reflective. A cutting edge is formed by the intersection of the two flat surfaces. The flatter and more polished the two surfaces, the sharper the cutting edge and the longer it will stay sharp. To flatten and polish the back face, choose from any combination of oil stones, water stones, diamond stones, Metalite® sheets and diamond paste. Place the abrasive on a solid, non-slip surface and work the blade with arms extended adding the weight of your upper body. The more pressure you apply, the faster the cut rate.

*To Flatten and Polish using Stones, Choose From the Following Options:*

Water Stones: 200, 1000, 4000, 8000
Oil Stones: Silicon Carbide, India, Arkansas
Diamond Stones: 220, 325, 600, 1200

*To Flatten and Polish Using Sandpaper Sheets Use:*

Metalite® Cloth Backed Aluminum Oxide Sheets:80, 120, 180, 240, 320, 400, 600

*For a Highly Reflective Finish:*

Diamond Paste: 3,6,15,30 microns (4-pack)
Use diamond paste for the polishing stage. Four grit sizes are recommended to achieve an exceptional finish.

*For Maintenance of Stones:*

Waterproof Paper: 120
With use, water stones and oilstones develop a concave wear pattern. To reflatten, attach waterproof sandpaper to a glass plate, wet, then 'sand' the stone until flat.

*Step 2 - Grinding the Bevel*


Creating the grinding bevel with a grinding wheel makes sharpening easier and faster. The grinding bevel does not affect the cutting characteristics of the sharpening bevel. The angle of the grinding bevel is about 25 degrees for a plane blade and as low as 15 degrees for a chisel - there is no standard angle. Use a slow speed bench grinder with a cool-cutting wheel. The best results come from a premium, white aluminum oxide, 60 grit, soft-grade wheel - (J) is your best choice. You control the cut rate and feed speed, so avoid heavy pressure and slow feeds, which can burn tools through over-heating. Over time, a grinding wheel begins to cut poorly and run hotter due to glazing. Expose fresh, sharp abrasive grains by removing the glaze with a wheel dresser. The restored wheel will cut faster, cooler and coarser.

*To Sharpen Using Grinding Wheels*

8" x 1" 60 Grit - J Grade
6" x 1" 60 Grit - J Grade
6" x 3/4" 60 Grit - J Grade

*Maintenance of Wheel*

Wheel Dressers, chose one of the following
Silicon Carbide Dressing Stick
Diamond Dresser with handle
*Step 3 - Preparing the Sharpening Bevel*

To create the sharpening bevel, you need to restore a flat face to the rounded blunt edge. Sharpening requires two grades of abrasive - both in the fine range. The first grade (4000) quickly removes the rounded edge. The second grade (8000) polishes the new flat face. Hold the blade either freehand or in a honing guide at the correct angle.

*To Sharpen Using Stones, Choose From the Following Options:*

Water Stones: 4000, 8000
Oil Stones: India, Arkansas

*To Sharpen Using Sheets, Choose:*

Metalite® Cloth Backed Aluminum Oxide Sheets: 400, 600

*For Maintenance of Stones, Choose:*

Waterproof Paper: 120
With use, water stones and oilstones develop a concave wear pattern. To reflatten, attach waterproof sandpaper to a glass plate, wet, then 'sand' the stone until flat.


*Select From These Norton Products:*


*Water Stones*

Water Stones use water as a lubricant and develop a fast cutting slurry with use. Water stones will quickly sharpen or lap a fine finish into planes and chisels. They are the choice of many professionals. Because water stones wear concave with use they must be reflattened periodically with waterproof paper sandpaper attached to a glass plate.
*Oil Stones*

Long lasting Oil Stones are economical and have been the standard of craftsmen for over 75 years. Oil stones will sharpen and hone a fine edge on any tool, but have limitations for polishing. Oil stones require Norton Oil to suspend metal and abrasive particles away from the stone’s cutting surface which keeps the stone free-cutting. Like water stones, oil stones required periodic flattening.
*Diamond Stones*

Diamond Stones are fast cutting and maintain a very flat cutting surface because diamond particles are bonded to a precise 1/4” metal plate. While more expensive diamond stones last a lifetime, never need to be reflattened, and may be used dry, they have limited polishing capabilities.
*Metalite® Aluminum Oxide Sheets*

Fast cutting and inexpensive, Metalite® Aluminum Oxide Sheets are formulated to cut steel. Unlike sandpaper for woodworking, these sheets are ‘close-coated’ providing more abrasive to remove metal faster. While inexpensive, sheets wear out quickly and must be replaced often. They also have limited ability to produce a polished surface.
*Diamond Pastes*

Diamond pastes contain diamond particles suspended in oil. The fine micron diamond particles lap a highly reflective ‘mirror’ finish onto the back face of planes and chisels. Diamond paste is not as efficient as the above products for sharpening the cutting edge of the tool and should be used in combination with a water stone, oil stone, diamond stone or sheets for best results.


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## Brian T. (Dec 19, 2012)

I expect a nearly mirror-smooth, slick surface with my wood carving tools. Even with Pfeil, I can feel the edge going away in less than 45 minutes steady work. Very hard to tell with mallet work.
If I have to, I'll start on a 1K waterstone, then 4K then hone with CrOx/AlOx. Most of the time, 5-10 honing strokes does the job.
1. Everything above works just fine and dandy.
2. Pick one method and learn it, they are all like that.
3. Dealing with damaged edges is something else again.

I estimate that I have pulled spokeshaves nearly 2 miles in birch. The same method(s) apply.


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## jacko9 (Dec 29, 2012)

I see that you already got some good feedback in the posts above so I'll just add to that input. Keeping a plane iron sharp has many variables as mentioned but the first is the quality of the steel and a lot of advancements have been made in that area. Some Japanese steel makers are producing high quality carbon steel, carbon alloy steel and power metallurgy forged steel that all have excellent "toughness" one of the main properties in keeping a sharp edge of a given hardness.

Sharpening stones also have been making great strides in the last decade whereas my old King Water stones would have to be flattened after a short sharpening session my newer Nubatama Ume stones stay flat for a very long time.

Sharpening angles are important but the method of achieving that angle can produce either a concave, flat or convex face and the latter can seem like a dull edge rather quickly. James Krenov always advocated a hollow grind and then developing an edge on the two ends of the hollow. Already mentioned is the importance of having a flat back edge but I have noticed that some sharpeners while trying to achieve a great mirror surface start of round over the back edge slightly.

Sharpening aids have been advancing rapidly and I have a 35 year succession of rather crude ones to the very well designed Veritas Mk II sharpener which just added a needed narrow chisel interchangable head which I used today to sharpen several 3mm to 6mm chisels very nicely.

One last thing, don't hand plane teak it's like running your blade over sandpaper!

Jack


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## Endre (Oct 25, 2017)

*SheperdCinder's *post tells a beginner everything about sharpening. Thanks a lot.


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