Sharpening of Chisels (again!)

[Jacob]

.....
A honing jig and coarse stone in this instance is in lieu of a grinder. It's no different than using a grinder tool rest. ......

It's much easier to grind freehand on a flat stone (or a flat sander) without a honing jig. It's much easier to grind freehand on a wheel with just a simple rest. It's really essential to get into the habit of eyeballing a near enough angle whichever method you use as it saves all that effin about with a jig.

 

[Trafalgar]

You might have to sacrifice certain pedagogical goals, temporarily, in order to save the program's tools and equipment. Nothing about woodworking is easy for a rank beginner. Some steel is sacrificed when learning to sharpen. If some manual dexterity can be acquired in other areas that translate back to honing (and not the other way around as is normally assumed) then overall program goals can be achieved without unnecessary loss of length of chisels and plane irons. It's a compromise. Jigs are mindless, I agree, but the fact of the matter is that they do work.

 

[Phil Pascoe]

Stropping is a waste of time with chisels that are used by (many) kids!

The sharpening interval reported by the OP suggests that stropping might be very viable.

Obviously stropping only works on edges that have minimal wear and weeks from sharpen to sharpen does seem to suggest that the chisels don't get heavy use or much abuse.

Is that weeks from hone to hone or weeks from grind to grind?

 

[Jacob]

.... Jigs are mindless, I agree, but the fact of the matter is that they do work.

They do 'work' but are still no use - in that it's quicker and easier without them.
I learnt to do it age 11 then didn't pick up woodwork again for many years by which time all the fashions, fads and gadgets were being brought in (early 80s) and I went down the jig route - only as far as buying a Stanley and an Eclipse jig, luckily I avoided the seriously daft and most expensive gadgets. Another stretch of many years later and I rediscovered how to do it freehand and have never used a jig since. I was astonished at how easy it is freehand (slightly rounded bevel) and sharpened everything in my shop really quickly - including all sorts of odd tools which I never use - I keep coming across them in the bottom of drawers, still razor sharp!
If you are under any pressure (lots of chisels for a class, lots of hand work to finish, need to sharpen stuff on site away from workshop, etc) then it's a no brainer.
But if you just like fiddling about with tools as a hobby by all means investigate modern sharpening fashions!

 

[Trafalgar]

I don't use a jig now, but have in the past. As mentioned and acknowledged, they work.

In a school environment, they preserve tool steel during the period of time students get their sea-legs and wheat is sorted from the chaff. If there are tools aplenty then by all means turn them loose on high speed dry grinders on Day 1. A lot of steel is going to go up in smoke, but if it's of no financial consequence then let it rip.

Otherwise, using a jig doesn't cause irreversible brain damage or stint the quality of one's work in any way. Most people who start out with them leave them at some point in due course. Even those that don't are still capable of fine work. Jim Kingshott was an enthusiastic proponent of using jigs, and used them himself -- for one example. Freehand sharpening really isn't necessarily the right of passage it's often said to be. And if one hollow grinds, the jig is simply ground into the cutter anyway in the form of the hollow, which provides both visual and tactile reference points.

 

[Jacob]

I don't use a jig now, but have in the past. As mentioned and acknowledged, they work.

In a school environment, they preserve tool steel during the period of time students get their sea-legs and wheat is sorted from the chaff. If there are tools aplenty then by all means turn them loose on high speed dry grinders on Day 1. A lot of steel is going to go up in smoke, but if it's of no financial consequence then let it rip.

Otherwise, using a jig doesn't cause irreversible brain damage or stint the quality of one's work in any way. Most people who start out with them leave them at some point in due course. Even those that don't are still capable of fine work. Jim Kingshott was an enthusiastic proponent of using jigs, and used them himself -- for one example. Freehand sharpening really isn't necessarily the right of passage it's often said to be. And if one hollow grinds, the jig is simply ground into the cutter anyway in the form of the hollow, which provides both visual and tactile reference points.

For me a few of the problems with jigs were;
don't work with non flat stones, so you have to flatten stones too
don't camber blades at all easily
not easy to apply a lot of force so it's a slow and fiddly process - for some stupid reason jig designers have left out attaching a handle which would make a little more sense of the concept
wheels in wrong place - should be behind not in front, then you could apply a lot of force and do the rounded bevel trick
not always available when you think you want one.
Make a simple job more difficult
Many others!

Have to say - I DO think freehand sharpening is an essential rite of passage - it's so easy and useful; makes sharpening a chisel or plane blade about as difficult as sharpening a pencil and means you can easily do it as and when, during the course of the work, just like a pencil.

 

[John15]

I imagine a jig would be safer than freehand for an 11 year old.

John

 

[Trafalgar]

I don't use a jig now, but have in the past. As mentioned and acknowledged, they work.

In a school environment, they preserve tool steel during the period of time students get their sea-legs and wheat is sorted from the chaff. If there are tools aplenty then by all means turn them loose on high speed dry grinders on Day 1. A lot of steel is going to go up in smoke, but if it's of no financial consequence then let it rip.

Otherwise, using a jig doesn't cause irreversible brain damage or stint the quality of one's work in any way. Most people who start out with them leave them at some point in due course. Even those that don't are still capable of fine work. Jim Kingshott was an enthusiastic proponent of using jigs, and used them himself -- for one example. Freehand sharpening really isn't necessarily the right of passage it's often said to be. And if one hollow grinds, the jig is simply ground into the cutter anyway in the form of the hollow, which provides both visual and tactile reference points.

For me a few of the problems with jigs were;
don't work with non flat stones, so you have to flatten stones too
don't camber blades at all easily
not easy to apply a lot of force so it's a slow and fiddly process - for some stupid reason jig designers have left out attaching a handle which would make a little more sense of the concept
wheels in wrong place - should be behind not in front, then you could apply a lot of force and do the rounded bevel trick
not always available when you think you want one.
Make a simple job more difficult
Many others!

Have to say - I DO think freehand sharpening is an essential rite of passage - it's so easy and useful; makes sharpening a chisel or plane blade about as difficult as sharpening a pencil and means you can easily do it as and when, during the course of the work, just like a pencil.

For those students who go on to become serious amateurs or even professionals it's not an issue, they'll likely move on to a 'freehand' method and will have no trouble teasing that out in their own shop in half a day or less. For the rest, the majority, it simply doesn't matter.

 

[D_W]

Does this wood shop have a belt sander?

Hello,

I guess this question is aimed at me...new workshop next term.?

Yes, there will be a vertical belt sander (band facer). I'm guessing you are reasoning if there is a belt sander used by the pupils then they should also use a dry grinder. Well not exactly, the comparison of the 2 machines is not exactly the same.

If the powers that be are true to their word, we will be getting a horizontal grinder for tool prep in the new building, nice...

If the suggestion is to the OP for using the belt sander as a grinder......a sure fire way to start a fire!

Mike.

The suggestion is that, yes (belt sander to grind). If the instructor does all of the grinding, fire should be avoidable.

I wouldn't put students in front of a dry grinder these days. I think they're apt to find a way to damage a wheel by misuse, and a damaged wheel at high speed is a dangerous proposition.

 

[Jacob]

........
I wouldn't put students in front of a dry grinder these days. I think they're apt to find a way to damage a wheel by misuse, and a damaged wheel at high speed is a dangerous proposition.

We were barred from using bench grinders. There'd be a massed rush for the grinder if the teacher was out of the room - rapid formation of steep bevels, rough edges, blued steel etc :roll: :lol:
We had to grind by hand on the coarse side of a double sided oil stone. Tedious but very good training.

I grind freehand on a belt sander nowadays. Runs cooler than a stone and you get a nice flat (or slightly convex) bevel. The convex bevel is good for power grinding (I think) as the contact point shifts as you dip the blade - so spreading the heat from friction.
I used to attempt to grind on a 6" bench grinder - result; overheating and the appearance of having been nibbled by rats.

 

[essexalan]

We were not allowed to sharpen at my school so blunt chisels and planes were the norm. Teacher used a Linisher (?) in the metalwork shop to grind the primary bezels although there was a large what was probably an electric sandstone wheel. You had to moan about how blunt the tool was before you got a sharp one. Dad taught me how to sharpen chisels and plane irons on oil stones but I was not allowed to strop them on my palm, next door neighbour taught me how to sharpen knives and all about the burr. Nothing difficult about grinding a primary bezel on a ProEdge and why not use the perfectly good jig fitted to it? Some people just love walking around in hair shirts ;0)

 

[Jacob]

We were not allowed to sharpen at my school so blunt chisels and planes were the norm. Teacher used a Linisher (?) in the metalwork shop to grind the primary bezels although there was a large what was probably an electric sandstone wheel. You had to moan about how blunt the tool was before you got a sharp one. Dad taught me how to sharpen chisels and plane irons on oil stones but I was not allowed to strop them on my palm, next door neighbour taught me how to sharpen knives and all about the burr. Nothing difficult about grinding a primary bezel on a ProEdge and why not use the perfectly good jig fitted to it? Some people just love walking around in hair shirts ;0)

I also use Pro edge and the tool rest. It's not quite a "jig" in that your blade isn't fixed at an angle - you can move it about in a freehand sort of way.

 

[RobinBHM]

My school had one of those Viceroy sharpedge grinders for chisels and plane irons.

I now have one in a joinery shop, they are great, no chance of ruined blued blades by apprentices!

 

[grumpy6165]

Many thanks for all your answers. It has a clarified my thoughts of what I need going forward.

I think an Eclipse type honing guide (to replace the poor quality Stanley one I have currently have) and a simple jig for setting the angles should be sufficient together with a spare set of chisels in order to rotate them as required.

In answer to the question to why pupils don't sharpen themselves its down to class size and time constraints.

 

[bourbon]

But also you have to think of yourself and your time. You have enough with marking and other ofstead crap. Quick and easy must be the way to go. My girlfriend was a business studies teacher, Two strokes later, she decided that maybe she had worked too hard.