Sharpening chisels
#11
  Re: (...)
I bought a set of cheap Stanley chisels from Amazon for $10.
They are not well sharpened right out of the package.
I have a chisel holder tool here, it works for plane blades too.

Anyway, what grit stone would I start with to shape & sharpen these things, so they're usable?
Will a standard double side stone work?

I also have a Wolverine sharpening system I can use too.

How would you guys go about sharpening these things up?
Reply
#12
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
For a long time I'd start with coarse sandpaper and work up through the grits. Then I got a grinder (Norton 3X 60 grit) and cut my sharpening time dramatically. I'm still not using an electrons (hand crank grinder), but I can get the bevel shaped and near sharp in seconds now rather than minutes. Then to a glass plate and sandpaper to 2000 grit. Still flatten the back by hand starting with a 140X Atoma diamond plate. Wet/dry silicon carbide paper is my choice. Easy to find to fine grits at auto supply stores - Napa here.
Reply
#13
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
Regardless of medium, IMO you want to get to the equivalent of 8000 (waterstone) grit at a minimum. Some folks stop at 6000 and then strop. Oilstone users often use only two stones and end with a strop.

When done, if your chisel will pare pine end grain with nice clean shaving (not dust) it's probably sharp enough for whatever task.

JMO & YMMV.
Thanks,  Curt
-----------------
"Life can only be understood backwards; but it must be lived forwards."
      -- Soren Kierkegaard
Reply
#14
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
Sounds like you need the basics. Do you have sharpening stones already? If not, then sandpaper on a flat surface is the cheapest way to start. If so, you need to know the grits on your stones.

1. Flatten the back to the highest grit you'll use. You can start with sandpaper on a flat surface (glass or your TS table, jointer, granite slab, etc.). You only need to flatten about 1/2" to 1" from the tip. I flatten to 8000 grit stone (~2000 grit if sandpaper).

2. Out of the factory, those chisels probably don't need to be ground on your grinder, but it helps if you're going to freehand it. The hollow grind you get from the grinder leaves less steel required to sharpen.

3. For general bench chisels, a 25 deg bevel is what you're after. You can set up your honing guide (chisel holder as you call it) to do this. Start at the lowest grit stone (I use 1000 grit as my starting point). If sandpaper, 120 or 220 grit.

4. Keep working your way up to 2000 grit sandpaper or 4000 grit stone. Between each grit, take a couple of swipes on the back side on the 2000 grit sandpaper to remove the burr formed on the back side of the chisel.

5. If you stop at 4000 grit stone, then get a stiff piece of leather, add some green honing compound to the suede side, and strop the chisel on the bevel side several strokes. If you have an 8000 grit stone, stop there. If you are using 2000 grit sandpaper, you're done. Don't forget to make the last couple of swipes on the back side of the chisel. Keep the chisel flat against the stone/paper when doing this.

6. The ultimate test of a chisel's sharpness is to pare end grain in pine. If you get shavings and not dust, you have achieved sharp.
Still Learning,

Allan Hill
Reply
#15
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
Choose the size chisel you're most likely to use, for multiple tasks.

For me, that's the 3/4" size. Concentrate on getting this single chisel sharp enough to use - and put it to work. Once it feels "slow", have at it again. Three iterations, and you should have a feel for getting one sharp.

I do not recommend sandpaper as a long term method, as it is VERY expensive over the long haul. Diamond stones are reliable, and if you give up sharpening by hand, easy to resell.

Factory edges are often coarse, as with your new Chisels.

Getting them sharp is an ongoing concern.

https://www.youtube.com/watch?v=i9sO7bLnBFA
Reply
#16
  Re: Re: Sharpening chisels by AHill (Sounds like you need...)
AHill said:



6. The ultimate test of a chisel's sharpness is to pare end grain in pine. If you get shavings and not dust, you have achieved sharp.




Or, more to the point, you do not compress the soft earlywood, but cut it cleanly with no "pit" and all shine. No cheating by drawing the chisel, straight ahead only.

That's for paring chisels or carving tools. Chopping tools don't need more than a hard Arkansas or about a 1000 FEPA (P1000) or 600 CAMI. Not a meaningful difference in operation.


Better to follow the leader than the pack. Less to step in.
Reply
#17
  Re: Re: Sharpening chisels by Anji12305 (Choose the size chis...)
There are a couple of things about the video posted above that would mislead a novice sharpener:

First, a lot of effort goes into making the chisel pretty, especially the part on flattening the back. The sharpener in the video works the entire back on the sandpaper, ostensibly to remove the rust. He pays little attention to the section of the back immediately adjacent to the edge, the most important part. Improving the appearance of a chisel has little to do with sharpening it, and removing the rust and making the back shiny is not the same as flattening it. It is not necessary to flatten the entire back of a chisel and to do so would involve a LOT of work. It is only necessary to flatten a small length of the back, say 1/2" or so, to achieve a good intersection of the back with the bevel. I don't mean to denigrate the effort to make the chisel look nice, who wants ugly, rusty chisels? But removing the rust is not sharpening.

Second, unless the sharpener is accomplished at freehand sharpening, I would recommend a sharpening jig to grind the initial bevel. It is difficult to keep the chisel held at a consistent angle while moving it over the sandpaper - or a stone for that matter. A novice at freehand sharpening almost always rocks the chisel front-to-back, rounding the bevel. The sharpener in the video does it and his resulting bevel is rounded, as one can see when he moves it in the light to inspect it. A rounded bevel does not absolutely kill the sharpening effort, but a flat bevel is preferred, unless you're sharpening a carving chisel where some prefer rounded bevels. A slight rounded bevel on a bench chisel makes subsequent sharpening difficult, and subsequent sharpening almost invariably increases the rounding until the chisel becomes unusable and one has to go back and regrind it. A sharpening jig may be considered "cheating" by purist freehand sharpeners, but until one develops the skill to grind a perfectly flat bevel freehand, a jig is the only way to accomplish a flat bevel; and a flat bevel will add immeasurably to the performance and enjoyment of a bench chisel.

My $.02.

Hank
Reply
#18
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
Herb

Make sure you take Lacquer thinner and steelwool to the chisels to take the coating off first.

Arlin
It is always the right time, to do the right thing.

Hi, I'm Arlin's proud wife! His brain trma & meds-give memory probs and has pain from injuries, but all is well materially & financially.  
Reply
#19
  Re: Re: Sharpening chisels by Arlin Eastman (Herb[br][br]Make sur...)
What AHill ^ said. Spot on.

Can't emphasize how important it is to get the backs flat before you ever touch the bevel. Be prepared for ALOT of work in a low quality set of chisels.

The operative word here is "cheap".

These are utility chisels and as such, they will not be flat or hold an edge. The extremely high side bevels will make dovetail work difficult.

I would recommend Narex. A starter kit will set you back about $50.
It will be good practice, though.
Reply
#20
  Re: Sharpening chisels by Herb G (I bought a set of ch...)
I'll chime in here with just one point about how you know you are done with a particular grit an should move on. This can happen in just a few strokes, so knowing what to look for can save you loads of time vs. not knowing.

With your largest grit (80 if you have really bad metal, perhaps 150 if you are just tuning up new but dull material) hold the chisel 180 degrees to the stone (sandpaper, etc.) and stroke until an even pattern of scratches cover the surface - say 1/2 inch from the edge on the back and on the bevel surface. When the scratches are uniform and there are no pits left (think old crappy chisel with pits) move up to the next grit. Now I suggest turning the chisel about 20-30degrees from 180 and begin scratching away again. When all of the scratch marks are in line with the new angle and there are no scratch marks at the old angle - your done. Switch back to 180 degree attack angle and rinse and repeat till done. At around 3000-6000 grit it gets harder (for me) to see the scratches. The surface goes from uniform cloudy to polished, see yourself in a mirror, surface. At that point you are pretty much done.

Just my 2 cents. I've found that with wetstones occasionally only 10-20 strokes are needed to move up between grits, depending on the degree of difference in the grits. YMMV.

Good luck.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.