Thread: basic setup, what do i need?

As above but I would recommend a slow bench grinder. Many a good chisel has been ruined by a fast grinder by beginers.

Are these the type of wheel people are referring to for their grinders?

I have an 8" Abbott and Ashby bench grinder so probably not a slow grinder but from what I can see these wheels don't generate much heat

Grinding Wheel 150mm Bench Grinding Wheel Aluminium Oxide - White BW 15020-32 AW 80 HSS | PFERD

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The tool edge must be awfully badly banged up to ever need a bench grinder. I have a 6 speed bench grinder that I will never use
for any kind of sharpening of wood working tools. Certainly not a $100.00 elbow adze blade.
I use it to remake edges from one thing into something else ( e.g. change a skew into a stop chisel).

A very bright light, a 10X magnifier and a black felt marker are the 3 most important sharpening accessories.
Do all the finishing work by hand. It's slow, only needed once and no chance of cooking the tool.

The risk of burning is overstated (though I'm not telling someone who likes to use a manual method that they shouldn't do it), and quite often due to subtle choices.

I've long used a full speed grinder, first with a coarse wheel and now with CBN. But, as CBN has gotten tired (I am a heavy user because I also make tools), it's no longer appropriate for anything on mine other than slow hollow refreshes.

What do I use for large adjustments? The coolest grinding fast device you'll find is something like a 5000 foot per minute belt grinder. There is no such thing in a reasonable cost range.

The next step down is a 24 grit wheel on a bench grinder (it can be full speed). the 24 grit wheels are almost like an open matrix (less dense than typical wheels). I use one on a full speed 8" grinder, which is often described as a no-no tool. If it had an 80 grit white wheel, it would blue a chisel in a hurry.

The 24 grit wheel with a light touch will outrun a broken in CBN wheel speed for speed and heat for heat despite the high wheel speed of my grinder.

IF you are thinking of doing significant work on a grinder and worried about burning an edge, take a paper towel and fold it into a rectangle about 8 layers thick and soak it or spray it until it's soaked with water. Let it sit all the way up to the edge on the chisel and you won't be able to burn the edge of the chisel. Put your finger pressure on the paper towel to push the chisel into the wheel - that assures you that you will not be applying pressure unless you're also putting water against the back of the tool drawing heat away from the edge.

If you are thinking "what happens when the grinder catches the paper towel". Nothing, it grinds paper towel off and you'll feel a light spray of stuff on your face. reset everything and go. When the water gets warm, you will feel it, but it will not boil off quickly.


I can easily grind by hand - why do I not do it? speed and precision. I like to hone just a bit of the tool bevel and the back, and I want a result that one would get working a flat bevel for half an hour. I want it in less than a minute. I also adjust squareness or reference to a cap iron freehand and the smaller the stripe of metal I'm working with the stones, the easier it is to make small adjustments all the time.

Remember - coarse wheel on a grinder first, worry about the composition of it second.

24 grit wheels are available here at industrial supply - they're slightly more expensive than the cheapest gray wheel, but by no means expensive. Perhaps $28 for a large 8" wheel, and half of that for a 6"x3/4 wheel.

(I did burn a chisel last week hand grinding it on a sandpaper lap - I thought I would make an entertaining video about heat and what's really required to maintain tools by hand - nothing expensive. I browned the corner of a chisel - like a fraction of a mm of the edge. I ignored it, honed it, and it works fine. Brown is only slightly off from factory tempering, and a tiny fraction of time getting to brown vs. tempering for half an hour to that temperature is almost unnoticeable).

Steels that don't spark are the worst for grinding heat. XHP/PM V11 grinds half as fast as O1 and creates a lot more heat. It's not unmanageable, but if you get used to good sparking steels, it's annoying. When I received a LV chisel last year to perform testing for a sharpening method, It needed to be ground back and I found no virtue in it based on the grinding - steels that grind well are better for an experienced woodworker than wondersteel's a-z. slow grinding and slow honing is a pain, as you'll damage the edge of almost anything form time to time, and grinding out damage on a steel that grinds a third or a half as fast as high hardness O1 is a nuisance - the fact that the slow grinding steel also doesn't shed the sparking very well compounds the problem and slows things down further.

I would certainly like to have a stationary belt sander.
I made a stop chisel (double bevel) from a skew. Very pleased with the efforts.
In any case, best for the rough-out stage, there's no finesse.

I claimed that I do all the fine finishing sharpening work by hand and not by machine.
Taken to the limit, of course over-heating from inept grinding is an issue.
As a fact, it becomes more important as the edge becomes thinner and thinner.
So I stop when I get the basic shape I want.
Silicon carbide papers or diamond plates create very satisfactory edges.

Originally Posted by Robson Valley

...
I made a stop chisel (double bevel) from a skew. ...

You have used a couple of terms that I am not familiar with, Robson. Don't know if its because they are carving terms or that you are on the other side of the Pacific. Perhaps you can enlighten me:

• stop chisel, and
• double bevel (on a chisel).

... Silicon carbide papers or diamond plates create very satisfactory edges.

Agreed, and when I used to use the "scary sharp" sharpening technique I found that the common white aluminium oxide sandpapers worked fine too.

At the risk of stating the bleeding obvious, this thread began with a request for advice on a basic setup for sharpening some bench chisels. We have had some excellent input around that from some of our practitioners.

But, keep in mind as you read this thread that sharpening blades for other purposes may benefit from quite different methods. Some of us need to sharpen blades for a range of purposes. One method won't necessarily do equally well for all blades and their uses.

Before you go too far down the path of any one particular method, think about what other sharpening you need to do. This may influence your decision and maybe save you some money.

A stop chisel for carvers has a double bevel. The total included bevel angle still should be something like 20 degrees.
The term arises in the London Pattern Book. Used by makers such as Henry Taylor, Ashley Iles, Pfeil and Stubai.
I had a Pfeil 1/8 and wanted something a little bit wider. I jointed a Narex 1S/12 (skew) and ground a 20 degree double bevel into that.

Sharpening is the same as for any chisel or plane blade. The difference might be in lifting the tool axis only 10 degrees for each side.
Freehand was a pleasant task beyond the grinding rough-out.

Originally Posted by Robson Valley

The tool edge must be awfully badly banged up to ever need a bench grinder.... I will never use for any kind of sharpening of wood working tools.

Whereas, in my case, 8" bench grinders with CBN or diamond wheels is about all I use in my woodturning workshop. I turn wood, so I reckon I'm woodworking...

If I'm turning an 18" platter on the lathe at about 1,000 rpm my gouges are cutting off almost 1 mile of shavings per minute. Even with exotic steels, a sharp edge has a very brief life, but it only takes me seconds to resharpen a gouge on a full speed CBN grinder... hand resharpening would not be a viable option, at least for me.

But, in the kitchen, my knives are only hand sharpened on the very best waterstones I can afford and they remain super sharp for may weeks before needing to be hand re-honed.

As I wrote in a posting above, blades used for different purposes can benefit from quite different sharpening methods.

Apologies for going off topic...... back to the sharpening of bench chisels.

Neil is right - once the basic question is answered in these threads, the thread turns from the main stem of a tree into a whole bunch of branches, but nobody makes lumber from branches just as most of the subsequent details make much usefulness to someone new.

So, here's a tip from me that you *will* be able to make something of as someone new, and don't let anyone tell you that it's not useful through their lens - their edges would probably look bad under mine.

Find yourself one of the small cigar shaped USB microscopes and use it to look at edges when you start. You will see things you can't see otherwise, and you can use this kind of thing for lazy purposes. Nothing matters on an edge other than geometry (edge provides support) and the polish level in the last several thousandths of an inch. Any other work done further up the tool is a waste of time unless it has a cosmetic purpose (on high end knives, etc).

But what I see far more regularly when I get tools in to refit is a lot of polish on parts of the tool that aren't in the cut and a lack of it at the very tip (or a lack of finishing the job).

search something like "hand held USB microscope" and just make sure the software that comes with the scope works with your operating system - anything that's $20 or $100 is pretty much the same thing, so don't spend more than the cheap ones.

You can use a scope like this also to teach yourself to get the most out of a given abrasive. Oilstones are always less refined than fine waterstones, right?

washita:
https://i.imgur.com/pRyqHc4.jpg

shapton 12,000 waterstone:
https://i.imgur.com/cGOlRds.jpg

The shapton 30k stones are finer than anything else you can get, right? (Sorry, no specific pictures for them, but the answer is no - $10 of graded abrasive is at least as fine and if used on wood instead of metal backer, greatly finer than a $360 shapton 30k glassstone).

But most importantly, just a little bit of time with the scope will let you see when you've finished the process sharpening and you can use it to look from edge to edge quickly.

Sorry, Neil, I keep thinking in terms of finishing work in wood carving.

The need for the magnifier, USB or a 10X geologist's loupe (solid state, no moving parts, no power required) is this:

If the tool has a sharp edge, there is nothing for light to be reflected by.
So you don't see anything.
However, when the tool edge is worn down or damaged in some way, the edge will have flat spots and they do reflect light.
Those are what I call "sparks" of light.

These are easy to see with sharp light as from a modern LED source.

Bad and I think of beginning with 600 grit.
Just a few sparks and not so bad? I'll begin on 800 then inspect the edge to see if I ground away the damage.
Maybe have to slip back to 600.

The scanning Electron Microscope pictures show just how soft steel appears to be at magnification.
The resolution is a dramatic improvement over light microscopes (so is the price).
What I gained from those was that going beyond 1,500 grit (3M = 3 microns) isn't an effective improvement.
My honing compound is 0.5 0.25 micron nominal particle size. It's effective as a final step
that needs repeating in hand work every 20-30 minutes.

This is sort of true (the visual appearance of 1500), but there are situations where it's not.

For example, a 1500 grit edge will only plane for something less than 65 percent of the footage of a 1 micron diamond edge. The 1 micron diamond edge can be added to the 1500 grit edge in the same time it would take to manage a wire edge from the 1500 grit edge.

I have only a visual metallurgical scope (along with the above mentioned cheaper cigar scopes). What I have found is that uniform abrasives around a micron just about eliminate visible scratches on steel. That's actually handy, as visible scratches left on steel will also indicate shorter edge life. (this has been confirmed by more than me).

If you do something to damage a chisel or carving tool, then this long (planing) life isn't going to be experienced. But the extra mile with no extra time is worth it on the planing side. All kinds of little manipulations of the tip of the tool at a high polish are worthwhile, but we can skip it here other than to say you can take a rubbery dime store iron and plane wood with silica in it without damaging the iron. Lack of edge damage even in nasty wood allows continued wood and really lowers the frustration level.

Surface brightness on wood is generally better up to about 8k, and then improvement is marginal. If you sand after planing or carving, then it really doesn't amount to much.

If the context is banging out joinery where the cut will never be seen, then really anything that is done to sharpen with the burr removed is fine and all of this grit talk is no big deal.

The nice thing about fineness, though - it costs almost nothing to get (despite snake oil salesmen and really expensive concoctions with alumina abrasive) - 1 micron diamond on cast is great, but so is autosol on medium hardwood or hard softwood - the finish level is about the same, and it needs to be done only at the tip.

Scopes doing visible light also have one nice side function (that happens by chance). On anything, including straight razors, the perception of edge improvement pretty much stops at the visible spectrum. If you see damage or coarseness at an edge, you will be able to feel it. You'll also be able to feel it in a plane when planing (and potentially see lines on work, or same with carving - if you're going to carve to finish without scraping or sanding, you need edge uniformity). As far as the razor goes, though, once a razor is satisfactory to the visible spectrum, there's nothing really to gain going finer, but if you are able to see finer, you may be convinced that it's still worth chasing (it's not).

In terms of 1500 grit edges and where they come up short? Unsuitable for smooth planing if you don't sand, and paring a show surface. I make planes for fun - if this style:
https://i.imgur.com/RnBIwC0.jpg

The front and back of the planes have four pared bevels. Even a washita edge can come up short on two of them - two will always be with the grain, two slightly against. Quartered beech isn't necessarily as agreeable as the stuff carvers like to use (butternut, balsa, mahogany, etc) but that surface has to be pared. It can't be sanded or scraped or anything else - if it's not pared cleanly, it loses its crispness.

we may be speaking the same language, though - if you're using your compound enough to completely remove all of the 1500 grit scratches, we're ending in the same place.

Here's two pictures:
* an edge that wasn't that refined, but the tip was refined by a quick buff with 1 micron compound:
https://i.imgur.com/XmxkY1k.jpg

You can see the scratches terminate just behind the end, and that the buffer finish is probably not all 1 micron - there are some very faint scratches. They can't be seen with the naked eye on a wood surface and are quickly worn off. The bigger scratches behind the tip would leave a hazy surface

* https://i.imgur.com/Pop9wfo.jpg

This picture is a 1 micron diamond treatment as part of a plane iron durability test - it takes four times as long to sharpen an iron this way vs. the one above (ignore the little fuzzies and black lines, they're probably filaments of shirt fabric, etc). The feel, surface left and durability of both is identical.

These are the things that you can learn with a scope and why I mentioned above that it's necessary for someone who is going to be appropriately lazy to get a scope.

Would you rather sharpen 4 minutes each time, or 1 minute? I know what I'd rather do. I don't know that I'd have backed into this without looking at edges.

(the buffed edge is also stronger and more resistant to early cycle chipping, but without giving up any significant edge life).

Thanks DW and RV for the sharpening clinic...

I agree with you both of you that some form of magnification is invaluable in understanding your edge during sharpening.

As a minimum I have found that a 30x and/or 60x loupe is essential to see what is going on at the edge. I always carry one with me between the locations where I sharpen various edges. I've found that a strong source of light is another important factor when examining the edge (... image brightness is inversely proportional to the magnification squared).

As a rule of thumb you need to go to about 500x magnifiction to see 1 micron. At that magnification steadiness becomes a factor and handheld is no longer an option... and definitely not for any of us seniors...

I've also gone through various digital scopes that claim to go at least to 500x, but with mixed success. They are invaluable if you want to communicate with others about the results you are getting from your sharpening methods. I reckon they deserve a separate thread for any of the sharpologists here who would like to chew the fat on that.