Sharpening chisels

[Luckbox]

I have a set of 4 Irwin blue handle chisels that I have used a few times. A few weeks ago I was trying to clean out some mortises in a table I am building and the results were not very clean. I saw that Rockler had the water stone kit on sale so I ordered it. Received it on Wednesday and decide today would be a good day to sharpen up the chisel set. I have just spent the last 6 hours sharpen one chisel and it still has not made it to the 10,000 grit stone. I started by trying to flatten the back of the chisel with a 250 grit diamond stone. I was never able to totally flatten it. There was a section about an inch long smack dap in the middle of the chisel that just wouldn’t flatten. I am sure if I spent another 4 hours I might have gotten it. I then worked on the bevel. I started with the 250 grit diamond stone and used a jig. I then used the 800 grit stone, but when I went to the 6,000 grit stone the outer edges of the bevel would not seem to sharpen. I got a great mirror finish on 90% of the bevel but was never able to get the outer edges. This is when I deiced I have had enough fun today.

This was when I asked myself how sharp is sharp enough and how everyone else sharpens there chisels. Do you use the water stones, or a grinder, or do you use a service. I have found a sharpening service that I might try since I feel there are better things I could do with 6 hours.

[JimD]

I do not use anything approaching a 6000 grit. I have a combination water stone and a little jig plus a wooden thing I made to set the angle with. I can normally get an edge acceptable to me in an hour or so to do my whole set of chisels.

I do not try to flatten the whole back of the chisel. If it is shiny near the edge, I figure that is the part doing the work so I don't spend time on the rest. I am not sure why the outer edges did not sharpen but if I push too hard, it can be hard to get a straight edge. The stone can also wear making it challenging to get a straight edge. I have a motorized wet grinder with a 1000 grit stone on it. I have not used it for chisels but might some day. I have not had too much trouble hand sanding and removing metal slowly has its advantages (I can mess up as quickly).

Jim

[Bruce Cohen]

There are probably more opinions and methods about sharpening as there are paint colors.

Everyone has their favorite way and most of us swear that their's are the best.

In my opinion, you're starting off with a "not so great" brand of chisels. Meaning that they're hard to sharpen. Chisels are probably one of the few tools where you usually get what you pay for.

Anyway, here's two books I found excellent in learning what to do, or not do.





I found the one by Leonard Lee (Lee Valley), although older, to be of more help, the other by Tom Lie-Nelsen (Lie-Nelsen tools) is much more theory oriented.

Either of them will end up being a big help and 6 hours spent sharpening is way too long. I use water stones made by Norton, a bit more expensive than the Japanese ones, but worth it. Also, I flatten the backs (chisels and Plane blades) using 600 grit wet/dry sandpaper spraymounted on a piece of float glass. If you can't get float glass, then thick tempered glass works almost as well. I know some people who use 3/4" MDF as a backing and swear by it.

Hope this helps you cut down your sharpening time.

Bruce

[DJehlik]

Here's a link to a 'Scary Sharp' method:

http://woodbutcher.net/scary.htm

Dave

[maxparot]

I myself have a set of Marples chisels and use a combination 1000/6000 waterstone. You started off properly but tried to go further than you needed to. When flattening the back you only need to work on the first 1/4-1/2". I start with a coarse diamond plate and progressively work through a 150/600 grit aluminum oxide stone before moving on to the 1000/6000 waterstone.
The only time I use the grinder is to rehab abused chisels. Once the bevel is set maintaining the edge is a lot easier than starting over.

[Luckbox]

Thanks, after trying to flatten the back of the chisel I was wondering if I needed the whole back flat. I kind of figured thank I only needed the first inch or so flat but in all the articles and websites I read they showed the whole back nice and shinny and flat. Just seems like a lot of work since only the fist inch or two are all that makes contact with the wood.
When I was using 800 grit wet/dry sandpaper on float glass to flatten the stones. I was amazed at how quickly the 800 grit stone losses flatness.

Later last night I went back to the garage, put the chisel in the jig and went back to the 250 diamond stone and started over on just the bevel. Within 20 min I had progressed all the way to the 10000 grit stone and had a perfect mirror finish on the chisel. I found that the stones only slightly damp seemed to work better than when they are wet. Or maybe my form was just that much better but it seemed like it took around 75 to 150 strokes per stone to true up the bevel nicely.

[gsmittle]

I've had good luck Scary Sharping my chisels. I got a granite block from Woodcraft and use water to stick down the sandpaper. I found that A-weight paper curls less than the heavyweight stuff. I soak the sandpaper in a glass of water, sandy side out, then stick it down on the granite. Now that I have a decent edge, it only takes about 10 minutes to touch it up with 1000 and 2000 grit paper.

g.

[gsmittle]

There are probably more opinions and methods about sharpening as there are paint colors.
Bruce

I think there are 42 more sharpening methods than paint colors...

g.

[scmhogg]

I also use and like the scary sharp method. I bought a 12" X 24" piece of 1/2" thick glass from a local glass company for about $20.

The new issue of American Woodworker [#125, November, 2006] has an article on sharpening chisels.

Steve

[Luckbox]

Funny thing you mentioned that Steve, last night I was just finishing up that issue and found the article.

[oakchas]

I use one of these to flatten the backs, and get a start on the edge. I then finish with scary sharp to about 2000 grit (sometimes 3000). It's a harbor freight tool, so I don't expect a tremendous amount out of it... but it has enough surface area to flatten most chisels (or at least the whole back). And then the finishing touches with the scary sharp method. works for me.

Here's the link to the item at harbor freight, and between that and the sandpaper, prolly less than you would spend on good water stones.
http://www.harborfreight.com/cpi/cta...emnumber=33867

[onedash]

i'll claim the worst method for sharpening. I actually have no method. I have tried almost every cheap method out there I think. I can get a chisel kinda sharp once in a while but in my quest to get it sharper it usually gets worse. My mortise chisels though are easy with the little kit I got for them. Kitchen knives are easy with my machine.