How do you sharpen your edges?

[lowell holmes]

There is a water stone thread going, I do not want to hi-jack it.

I have an oil stone, diamond plates, and a granite slab with sand paper on it and water stones.

Being lazy, I use the diamond hones. I keep one out on the bench and keep my edges sharp.

The granite slab with wet sand paper on it will make edges insanely sharp.

[Doug Hepler]

Lowell,

You wrote: The granite slab with wet sand paper on it will make edges insanely sharp. Yes, indeed. My "sharpening station" for many years has been PSA backed sandpaper on a Corian cutoff. It stores very easily and is always ready to go without fuss or mess (well, a few drops of water) But I would like to know more about your diamond hones. What sizes and what grits?

I avoid participating in sharpening threads but I just had to chime in. IMHO sandpaper sharpening is clearly the least expensive and most effective method. I have fantasized about a Tormek but I don't think I would get sharper edges in return for the expense and space requirement. But I am curious about how diamond hones fit into your system.

Doug

[Patrick Chase]

IMHO sandpaper sharpening is clearly the least expensive and most effective method.

It's important to distinguish between start-up costs (i.e. what you have to invest before you can sharpen your first tool) and ongoing costs (cost per incremental sharpening after the first).

Sandpaper sharpening is indeed the least expensive by far in terms of start-up cost, but it's also the most expensive in terms of ongoing costs. When you buy a set of waterstones or oilstones you're buying the equivalent (in abrasive life) of hundreds or thousands of sheets of sandpaper, depending on grit # and binder hardness. With the stone you have to pay for all of that abrasive up front, whereas with sandpaper you pay as you go, but the sandpaper definitely costs more per sharpening when all costs (startup and ongoing) are amortized out over the equivalent of a stone's life.

The only exception is at very low grit #s, say <200 or so. In that case the stone will have fairly limited life because it doesn't contain many "layers" of abrasive, and sandpaper becomes more competitive.

The economics of a Tormek are basically the same as those of a stone, but you pay extra up front for a VERY big stone (that's shaped like a wheel :-), a motor, and some fancy jigs to make things go faster.

[Graham Haydon]

20170819_194054.jpg

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Click on an image for a better view.

https://www.sharpeningsupplies.com/N...e-P69C126.aspx I'd recommend the 8 x 2 combination stone.

Add a grinder for when and edge gets chipped.

I've tried other things, because I'm very used to this (20 years now) the other options seems like expensive faffing about. I will also add autosol to leather or a block of wood if I want a really fine edge.

One last thing, when I used to muck about with videos, I once got a nice comment about my honing "The honing technique looks very good, very clean and crisp."
See comment number #4 http://www.sawmillcreek.org/showthre...king-a-log-bin

[Patrick Chase]

One last thing, when I used to muck about with videos, I once got a nice comment about my honing "The honing technique looks very good, very clean and crisp."
See comment number #4 http://www.sawmillcreek.org/showthre...king-a-log-bin

That's a rare compliment indeed. I think he was/is right about body mechanics btw.

[Graham Haydon]

Agreed, I'm hoping to get back to my "non work" workbench soon, Patrick. Hopefully I'll further improve my planing. I think that log bin was perhaps the last thing I made in my own time, eager to get going again!

[Doug Hepler]

I often see the claim that sandpaper honing is expensive compared to waterstones. These claims are unsupported by the facts, unless you assume that the sandpaper must be changed much more often than is necessary. I think that this assumption, about how often a sheet of sandpaper will last, is actually the root of the disagreement. I do concede that coarse paper must be replaced frequently when you are trying to remove a lot of steel, e.g., flattening the sole of a plane. But when honing already sharp edges, a sheet of SiO2 sandpaper still cuts to a very satisfactory degree after many sharpenings.

The following prices are from the Lee Valley online catalog and Amazon (for the 220 grit paper) in March 2017.

8000x Water Stone $99.00 vs. 0.5µ Chromium Oxide paper, Plain $2.70/sheet
4000x Water Stone $69.00 vs. 5µ Silicon Carbide, PSA $3.25/sheet
1000x Water Stone $52.50 vs. 15µ Silicon Carbide, PSA $3.25/sheet
220x Water Stone $31.50 vs. 220 grit Silicon Carbide $1.73/sheet
Truing Stone for Water Stones $34.50 vs plate glass, granite, negligible cost??
TOTAL $286.50 for waterstones vs. $10.93 for sandpaper

As far as I know, these Norton waterstones are the least expensive that Lee Valley sells. I see people recommending very much more expensive stones. So I am being conservative. The stones are 7-7/8" x 2-7/8" . The sheets are 8½ x 11" So each sheet yields 3-4 hones of equivalent size to the stones. So, clearly, the initial investment in sandpaper sharpening is about 4% of the initial investment in waterstones. I cannot estimate lifetime costs because I don’t know how long the waterstones would remain useful. Mine wore away quickly, especially because I kept them flat. I think two sheets of paper (6-8 hones) might be enough to last a year. So say the annual cost of sandpaper sharpening is $20.00. So, the “break-even” point is about 14 years out. I wonder if waterstones, which need to be flattened after each session, will even last 14 years. Maybe so, but the idea that sandpaper sharpening is “too expensive” is not supportable by facts.

Of course, I do not care what people do in their own shop. Stones are certainly in vogue right now. But I feel that we are obliged to base our opinions on fact. Otherwise, the range of our opinions will "overwhelm" the newcomer, as stated above.

Doug

[Patrick Chase]

I often see the claim that sandpaper honing is expensive compared to waterstones. These claims are unsupported by the facts, unless you assume that the sandpaper must be changed much more often than is necessary. I think that this assumption, about how often a sheet of sandpaper will last, is actually the root of the disagreement. I do concede that coarse paper must be replaced frequently when you are trying to remove a lot of steel, e.g., flattening the sole of a plane. But when honing already sharp edges, a sheet of SiO2 sandpaper still cuts to a very satisfactory degree after many sharpenings.

Sandpapers and stones use the same abrasives: SiO2 (arks, JNats), AlOxide or Alumina-ceramic (India, most synthetic waterstones), or SiC (Crystolon, some synthetic waterstones). Each abrasive particle lasts roughly the same amount of time in either medium. The difference is that there is one layer of abrasive in a sheet of sandpaper, versus many layers in a stone. That's what drives the economics.

Consider a 2000# stone, with a grit size of about 5 um (JIS). A 1" thick stone therefore contains on the order of 25 mm / 5 um = 5,000 layers of abrasive particles. However long you claim a piece of 2000# sandpaper will go, a 2000# stone with the same abrasive type can last thousands of times as long, subject to three assumptions: First, that they're the same area. Second that the stone's binder is hard enough to "fully utilize" the abrasive particles before releasing them (this is why we use hard stones for "easy" steels and softer stones for exotic steels). Third that you don't abuse the stone, for example by honing in one spot such that you waste huge amounts of abrasive via flattening.

Obviously the waterstone doesn't do quite as well at 100# (150 um particles, ~170 layers of abrasive), but at high grits sandpaper and films are orders of magnitude more costly.

I cannot estimate lifetime costs because I don’t know how long the waterstones would remain useful

If you cannot estimate lifetime costs then why did you claim an understanding of the relative total costs of sandpaper and waterstones? The difference between the two is fundamentally a matter of relative life. If you don't understand the mechanisms underlying lifetime then you can't possibly understand the economics.

EDIT: Softened in light of subsequent concern (removed first sentence)

[Jim Koepke]

I cannot estimate lifetime costs because I don’t know how long the waterstones would remain useful. Mine wore away quickly, especially because I kept them flat. I think two sheets of paper (6-8 hones) might be enough to last a year. So say the annual cost of sandpaper sharpening is $20.00. So, the “break-even” point is about 14 years out. I wonder if waterstones, which need to be flattened after each session, will even last 14 years.

Sometimes in a single day I may hone more than 6-8 blades.

The idea that water stones need to be flattened after each session is a myth.

My water stones are more than 10 years old and will likely last another 10 at least.

If one wants to go an inexpensive route, a few good oilstones might be purchased for less than water stones.

Sandpaper on steel wears rather fast. One of my early attempts to sharpen on the cheap was with abrasive sheets. They can give up their grit rather quickly.

jtk

[Patrick Chase]

Sandpaper on steel wears rather fast. One of my early attempts to sharpen on the cheap was with abrasive sheets. They can give up their grit rather quickly.

High quality monocrystalline diamond lapping films can last a very long time, but only if you're very careful. The diamond abrasive particles in those are extremely durable, but can be "stripped" from their resin backing by sharp burrs/nicks. The underlying polyester film is also easy to gouge.

On a related note, what I said earlier about the economics of stones doesn't apply to diamond plates. Those have only a single layer of abrasive, so in terms of abrasive life a stone isn't inherently better than a film. Plates do last longer in reality because nickel electroplating retains diamonds better than resin, but even so I'd take 10 sheets of the 3M 668X film that LV sells over a quality diamond plate (they're about the same price).

[Pat Barry]

...even so I'd take 10 sheets of the 3M 668X film that LV sells over a quality diamond plate (they're about the same price).

I'm confused - did you just come full circle? 3M 668X film == that's just a form of scary sharp isn't it?. Probably a lot more expensive than regular wet or dry sandpaper.

[Patrick Chase]

I think two sheets of paper (6-8 hones) might be enough to last a year.

Wait, you hone 6-8 times a YEAR?

Yeah, OK, sandpaper is unquestionably the right choice for your [non-]use model because you'll never amortize the up-front costs for anything that lasts longer. As Jim said, most of us hone multiple times per day, at which point the cost of sandpaper really adds up.

[steven c newman]

When I am chopping things at the bench...mortises and such....Every so often, I will give the edge and back of the chisel in use, a few strokes along the pants leg of my jeans....then back to work.

Keeps things sharp enough to last the project. 5-6 passes on the bevel...couple on the back....simple and quick to do.

[Patrick Chase]

I do not like to respond to flamers by name because it often just encourages them. You definitely were NOT included.

Nobody was flamed in this thread.

You made a very strong claim that my opinion was "unsupported by facts", and I replied with an equally strong post explaining in detail why that was wrong, except perhaps for very light use. Both posts were contentious, but neither were flames.

I often see the claim that sandpaper honing is expensive compared to waterstones. These claims are unsupported by the facts, unless you assume that the sandpaper must be changed much more often than is necessary.

[ken hatch]

Someone always has to drop a BabbyRuth in the punchbowl, I guess this time is my turn. First I can't believe folks go to that much effort for what should be a simple process unless you are Brian getting ready for his contest. The bottom line, no matter how supper sharp and polished the iron with it's first contact with wood it is no longer "supper sharp" and becomes working sharp. Working sharp can last awhile mostly depending on the type of steel, "stones" used and stropping can help depending on smoothness and scratch pattern you started with.

....KISS and go work wood.

OK back on my meds,

ken