flattening chisels backs

[tablesawtom]

Nice setup.  It'll certainly save time for chisel backs that are way out of flat.

There' s a Paul Sellers video of him preparing an Aldi chisel for use.  The back needed some work.  It was hollowed, which is a good thing from a getting the back flat perspective.  Sellers maintains (and I agree) that there's no need to flatten the entire back of the chisel.  Just the first few millimeters of the cutting edge.  He did progress through the grits on the back to get it mirror smooth.

First of all flat and polished are to different things and have nothing in common. Much like hole size and hole location.  One can have any sized hole at any location as long as the material will support it. And second of all I don't care if  Sellers maintains (and I agree) that there's no need to flatten the entire back of the chisel. I like mine flat and I make them that way because I can. Can does and can't finds fault with it.

Tom

[AHill]

First of all flat and polished are to different things and have nothing in common. Much like hole size and hole location.  One can have any sized hole at any location as long as the material will support it. And second of all I don't care if  Sellers maintains (and I agree) that there's no need to flatten the entire back of the chisel. I like mine flat and I make them that way because I can. Can does and can't finds fault with it.

Tom

I wasn't criticizing your desire to make things flat.  Just pointing out to anyone else reading this thread that there are different opinions on what's necessary when prepping a chisel.  Everyone doesn't have the skills you do to make jigs that make life easier.  It's a skill I admire.

I disagree flat and polished have nothing in common.  It's very difficult to get a mirror finish on a surface that isn't flat when you're using stones to do the prep work.  You can certainly polish an unever surface using buffing wheels or what-not, but that's not how most people prep a chisel.

[CStan]

Polish is usually what happens when you're trying to make something flat. Flat has a definition within geometry. Polish is only in the eye of the beholder. A lot of people scoff at a level of polish that looks less than liquid mercury. You can get to "flat" well before that level of polish is imparted.

[Timberwolf]

Polish is usually what happens when you're trying to make something flat.  Flat has a definition within geometry.  Polish is only in the eye of the beholder.  A lot of people scoff at a level of polish that looks less than liquid mercury.  You can get to "flat" well before that level of polish is imparted.

...............
You can put a high polish on a steel ball

[CStan]

Good one!

Hopefully the OP won't polish and polish and knock something out of flat, or round, as the case may be.

[Hank Knight]

Tom, do you have access to a surface grinder again?

[Tony Z]

It is a surface grinder. The head  moves up and down on a lead screw. The table moves back and forth and in and out.  Here is an other picture of a surface grinder. This one has coolant.



Tom

I do not know how to use a surface grinder! But I have multiple surface grinders (and a host of other types of grinders), and I employ some that know how to fixture and grind. I accumulate old tools, and unless of a value that the tool should not be fussed with, I have a tendency to have one of my guys flatten to sole and square the sides. I have also had a chisel or two flattened, but no longer mess with chisels, as it takes too long (and I am paying my guys!).

There is something very satisfying about taking an old tool and making it work like a brand new LN or LV! Many years ago, I bought one of the $7.50 Harbor Freight smoothing planes (I posted the write up years ago on SMC). I had the body trued up, bought a replacement blade from Jim Reed (haven't seen him around in years!), refinished the tote and handle with oil and made a new cap iron. Besides the purchase price, I think I had another $75 to $85 in labor and materials. The upside? Easily .001" shavings in cherry!

Now this doesn't exactly relate to Tom's work on chisels, but I seem to suffer from some of the same afflictions as him: making a tool as close to perfect as you can! Well done Tom!

[bandit571]

Almost have these two done,,,

   
To the point that they can get see through shavings in end grain Ash..

   
Both backs had almost a Japanese style hollow  (ura) in their backs..

   
Also worked on a yellow handled one..

   
The middle 3rd of it's edge was...gone...

[Admiral]

Can does and can't finds fault with it.

Excellent observation; I'll have to remember that one!!

Reminds me of this semi-famous quote:  "Confucius say:  Man who say it cannot be done should not interrupt man doing it . . ."

[AHill]

All this discussion about "polish" not necessarily applying to flat can be confusing and may not apply. If you are flattening your chisels using a flat stone or flat sharpening media, a polished surface is almost always flatter than a dull or matte one. I have rarely ever seen a surface flattened on an 8000 grit stone that didn't look like it was polished. I understand that a mirror finish doesn't guarantee flat - but sharpening involves primarily using flat media, so it's highly unlikely you're going to get a mirror polish on a surface that isn't flat. Two Cherries is one example where a mirror finish does not mean flat. That's because their chisels are polished at the factory with a polishing wheel prior to delivery vs. flattened on stones or abrasives mounted to flat surfaces. I checked some sharpening instructions out there. Lie Nielsen and Japan Woodworker recommend polishing the back of the chisel - at least nearest the cutting edge. I'm not home now, or I'd check the sharpening books published by Leonard Lee and Ron Hock.