Narex cranked chisels

[IanW]

I was pursuaded to join the rush to grab a set of these cranked chisels when Lee Valley promoted them a month or so ago. I didn't want a full set of the darn things, but the LV introductory price was ridiculously cheap, and a certain friend persuaded me that buying a set was a better choice than waiting to get one at an individual price - look at the money I would save!

So a set duly arrived. The chisels looked pretty good and even have quite well-turned handles that any reasonable person could probably live with. But I'm not reasonable when it comes to handles (obsessive would be a better description) and apart from being bland, unfinished Birch (I think), the handles seemed longer than necessary. These are the sort of tool that I often need to get into tight spots, cleaning up glue squeeze-out & so forth, so some reduction was called for. After mulling it over for a bit, I decided the best shape for a handle would be a simple, elongated egg, something that would fit neatly in my hand, with a comfortably fat end to push on. So I grabbed some Brigalow and knocked out a prototype: Handles cf.jpg

After hefting it a bit & trying some practice cuts, I reckoned that would do nicely, & the siblings got the same treatment: Narex chisels rehandled.jpg

OK, that was the easy part. The couple of rubs I gave the back of the 1" chisel showed it was a bit shy of flat, so I set about some serious flattening. The factory finish had left a slight side to side hollow along the back. This would have been fine if it had started back of the cutting edge, like Japanese chisels, but the hollow included the cutting edge. You can see the slightly uneven hollow clearly after a few rubs on a coarse diamond stone: Flattening1.jpg

A good many more minutes and it's starting to look flat: Flattening2.jpg

There is a "99/1 rule of flattening" (99% of the work goes into flattening out the last 1%), but a chisel like this has to be dead flat to work as it should, so I pressed on (and on!). Eventually, I got rid of the crescent at the cutting edge: Flattening3.jpg

The other chisels were a little closer & took less effort, partly because they are narrower, of course, but the good news is, it didn't take too long & they all took a nice polish & edge on the fine stones & passed the end-grain paring test very well. Time will soon tell how they hold that edge, but Narex are earning a reputation for good steel at a good price, so I'm hoping they keep up the family tradition.....

Now, I just have to figure out which ones I'll keep, and where I can stuff them into the tool cupboard.
Thanks, Brett.....

[FenceFurniture]

Nice work Ian.

I will persist (sniff) with the handles as they are....for the moment anyway

It was indeed these very chisels that were the force behind this thread.

[IanW]

....It was indeed these very chisels that were the force behind this thread.

Didn't see that, Brett - I don't go to the 'sharpening' thread, too scary, there!

Your travails with trying to lap backs with stones doesn't quite jibe with my experiences, so dunno if we have different expectations, or my stones are all 'off' by the same amount, or what. I do notice very small differences when moving from one supposedly flat surface (be it diamond plate or stone, or whatever), and that's reasonable, since we can detect finer & finer differences by the surface left by finer abrasives. However, any 'off' spots soon disappear as I go up the grits, showing my surfaces are pretty damn close.

Whatever method you use to sharpen, you are always going to get some rounding of the advancing edge, it just has to happen because slurry containing loosened cutting particles & metal particles off the object being sharpened are moving under the advancing edge. To minimise this, I go over the edge of the stone with the front on each stroke to reduce the cut on the front 5mm or so. I also try to move to the next grit as quickly as possible, since the effect is reduced for each diminution in grit size. Getting a truly flat back at the cutting edge is not an easy thing to do, but absolutely essential on a paring chisel, we are agreed on that!...

Cheers,

[FenceFurniture]

As it happens I've just this minute finished my set of parers. The ¼" bevel in particular was well out of square to the body - perhaps ½mm longer on one side. You get what you pay for with Narex, and as long as that includes good steel that will take a good edge then the rest can be pretty much solved. Like you, my backs were well out of flat.

Tough steel, innit?

[FenceFurniture]

Hey Ian, did you notice any weird stuff with these chisels when you were flattening them on your diamond plates? Every 10-20 strokes I would get a crunching sound and very coarse feeling for a stroke or two, and sure enough there was a bunch of extra deep gouges at the heel of the blade. It kinda felt like a diamond was being yanked off and gouging it, but equally it could have been a metal particle I suppose.

I got this with all four chisels, so it was consistent, and I got it with both diamond plates - one is a DMT solid plate (i.e. not the mesh type) and the other is an Atoma with its little clusters of diamonds in a pattern.

The gouges were were always at the heel (and so actually don't matter), so I figure it's something to do with the shape of heel.

[IanW]

Hey Ian, did you notice any weird stuff with these chisels when you were flattening them on your diamond plates? Every 10-20 strokes I would get a crunching sound and very coarse feeling for a stroke or two, and sure enough there was a bunch of extra deep gouges at the heel of the blade. It kinda felt like a diamond was being yanked off and gouging it, but equally it could have been a metal particle I suppose.

I got this with all four chisels, so it was consistent, and I got it with both diamond plates - one is a DMT solid plate (i.e. not the mesh type) and the other is an Atoma with its little clusters of diamonds in a pattern.

The gouges were were always at the heel (and so actually don't matter), so I figure it's something to do with the shape of heel.

No, didn't have anything like that happen, Brett. I did notice they produced a particularly copius black swarf during lapping, but that's something I notice often enough, especially on older tool steels.

I have certainly experienced something similar to what you describe, though. A sudden extra biting, and some deep scratches appear on the lapped face. I don't think it's loose cutting particles, because the scratches are much bigger than the ones left by the particular grit in use. I think what is happening is that every now & then, a largish chunk of hard material gets torn out of the tool, & that's what does the damage. I'd noticed some older chisels did this more than others, but what set me thinking about the cause was when I tried re-hardening a bit of butter metal that was shaped like a chisel. I quenched it in straight water, which is not clever, especially as I had no idea what sort of steel it is. Anyways, it went glass-hard & brittle, and my tempering was inadequate, so it is still a useless thing. When I started flattening the back, it felt like I was rubbing it over coarse gravel - great black chunks broke away & cut deep streaks on the surface. My guess is it's to do with the alloy & the way the martensite domains form as it cools. The fact that you noticed the effect towards the heel makes me wonder if it's something like this you are seeing at the point the solution reached when it was quenched, or something like that? I didn't lap the cranked chisels more than about halfway along the blade, so probably didn't get into the zone where that occurred (if that's what it is).

I'm curious, now, so I'll give mine a bit of work over the heels, sometime, & see if I get the same effect as you did.....

Cheers,

[JDarvall]

Whatever method you use to sharpen, you are always going to get some rounding of the advancing edge, it just has to happen because slurry containing loosened cutting particles & metal particles off the object being sharpened are moving under the advancing edge.

probably why japanese chisels are hollowed eh. Makes you want to hollow your western chisels with a grinder. I actually did that once to an old chisel to speed up flattening. Ground a hollow first, and found it flattened very quickly afterwards.

[Heavansabove]

probably why japanese chisels are hollowed eh. Makes you want to hollow your western chisels with a grinder. I actually did that once to an old chisel to speed up flattening. Ground a hollow first, and found it flattened very quickly afterwards.

I use a Dremel grindeing cone with most old chisels to reduce the time to flatten the back and eliminate the dubbbing over of the back that seems almost universal with flea market chisels. Might not be period correct, but saves a lot of time!

[JDarvall]

I use a Dremel grindeing cone with most old chisels to reduce the time to flatten the back and eliminate the dubbbing over of the back that seems almost universal with flea market chisels. Might not be period correct, but saves a lot of time!

glad someone else does that too.

maybe could even do it with new chisels. maybe if there's worry that a free hand grind will look too ruff with new chisels I bet it be easy enough to rig up a jig to hollow them.

with grinder method I can think of a method. the curvature you find in japanese chisels looks similar to the curvature of a 8" grinder wheel (slow speed if your worried about burning) . you could run a plywood jig off a grinder rest, with the table of the rest pointing at the centre of the wheel. To get the sweep, you could have matching female/male pieces of plywood that move smoothly. one of the pieces clamped to the bed. the other gripping the blade perpendicular to the bed…..just swing the blade across the grinder. and nudge clamped piece closer to wheel every couple of passes or so…..something like that. (insert shug smily thing here)

just an idea. I'm not an expert chisel hollowing expert. 2 cents worth.

[bridger]

I have a small pneumatic angled die grinder set up with an appropriately 2" grinding disc. Lightly running this down the center held at a low angle does a pretty good job of hollowing out the belly of a chisel. I generally go back and forth beteen the grinder and a stone, using the shiny spots produced by the stone to guide me as to where to grind.

[fields]

How do you guys keep the dremel from going too deep or causing too much damage when attacking the back of your used chisels?

I picked up two used chisels with very odd grinding marks on the back, i flattened most of them out but there are still some ugly marks, when I evenetually get the tip back that far, I think they will cause problems.

[Heavansabove]

How do you guys keep the dremel from going too deep or causing too much damage when attacking the back of your used chisels?

I picked up two used chisels with very odd grinding marks on the back, i flattened most of them out but there are still some ugly marks, when I evenetually get the tip back that far, I think they will cause problems.

The Dremel is variable speed which helps, and also is quite small and low powered so not hard to control. Also as someone mentioned above, only a small amount is taken off, followed by rubbing on the stone the determine progress, followed by a little more grinding... even a kack hander like me can do it. I do put the chisel in a metal working vice.

Cheers
Peter