turning chisels sharpening question

[Anna]

I hate sharpening, but I found that with some woods (rosewood?), dull chisels are a bear to work/play with. So I finally set up the bench grinder with my Wolverine jigs. Using the gray stones that came with the grinder, I proceeded to sharpen my gouges. Since I've never done this before, I had no idea how long I was supposed to hold the chisel against the stone, resulting in turning them blue (not sure if that's the right term).

One chisel looks pretty bad. I've since replaced the stones with the pink ones from Woodcraft.

So.... How do I fix my ruined chisels? They're all HSS. The only thing I could think of is to spend time to grind the chisels down until I grind through the ruined edges. Is that really the only option? I mean, I don't mind, but it takes a while because I did a really bad job with them initially. I'm also getting pretty paranoid about ruining them again, and I end up taking a very long time with each chisel.

Thanks,
Anna

[maxparot]

You did ruin those tools but they can still be useful. They won't keep a sharp edge very long since you overheated them. Use them to practice your sharpening technique. Keep a cup of water by the grinder to cool the tool in and use it often. Even with the pink or white stones on a high speed grinder you can overheat the tool if you aren't careful. With practice, good technique and well maintained tools it is possible to use even the gray stones.
Others have found the need to use slow or variable speed grinders, wet stone or water fed grinders are also available.
Once you are confident with your sharpening abilities get another set of tools for your work.

[Anna]

Max, thanks. So are you saying the chisels are ruined for good? They're Sorbys, and although I'm not sure whether or not they're the best stuff, they weren't exactly inexpensive either. But if they're ruined, then I guess I have no choice. (I'm kinda going nuts over this woodturning thing. It's way too addicting.)

Would a Tormek or something similar be better? I do have a WorkSharp, but I have no idea what jigs are available for sharpening turning chisels. I'm not even going to attempt free-hand sharpening these things. Is there a water wheel that works with the Wolverine jigs?

Anna

[Jim Boyd]

I was taught that the cheap chisels were ruined when heated to blueing when grinding. One of the reasons to get HSS chisels is that this did not effect them. And this has been my experience.
Just keep using your Wolverine and a light touch and you will eventually get past the blue marks

[Ken Massingale]

Blue-ing them isn't good, but hopefully the Sorby's aren't lost. Hopefully you didn't change the original bevel. Paint the bevels with a black marking pen, adjust the jig leg by eye to match the bevel with the stone (I only use the fine grit stone for sharpening turning tools), turn on the grinder and lightly touch the bevel to the stone. Check if all the ink is gone from edge to edge on the bevel (top to bottom, not side to side). Adjust the jig until the ink is removed evenly from the bevel. The jig is now adjusted to the correct angle. Now lightly roll the bevel against the stone, checking that the ink is evenly removed. Just make as few passes as necessary to get a nice edge across the profile. Again, a light touch, just enough pressure to keep the bevel against the stone without it jumping.

Are you using an 8" slow speed grinder, Anna?

[blame]

i'm sorry but i disagree that the chisels are ruined if you can locate a custom knife make or anybody with a forge you can have them re temper the steel and since there sorby chisels this would be the route i would go should cost very much

theres even away you can do this your self if you have torch oxy/propane or just a propane with a rosebud tip will work take a large scrap pcs of steel 3/4" thick heat till its red hot place your chisel on the heated scrap steel till it worms to a dull straw color or about 450 deg to 500 deg then dip it into mix of transmission fluid and bacon grease
leave for about 45 seconds then place back into the mix till it cools completly that will reharden the steel to retemper the steel all you have to do is bake it at 250 deg for 1 hour


blame

[Anna]

Blue-ing them isn't good, but hopefully the Sorby's aren't lost. Hopefully you didn't change the original bevel. Paint the bevels with a black marking pen, adjust the jig leg by eye to match the bevel with the stone (I only use the fine grit stone for sharpening turning tools), turn on the grinder and lightly touch the bevel to the stone. Check if all the ink is gone from edge to edge on the bevel (top to bottom, not side to side). Adjust the jig until the ink is removed evenly from the bevel. The jig is now adjusted to the correct angle. Now lightly roll the bevel against the stone, checking that the ink is evenly removed. Just make as few passes as necessary to get a nice edge across the profile. Again, a light touch, just enough pressure to keep the bevel against the stone without it jumping.

Are you using an 8" slow speed grinder, Anna?

Ken, I think it's too late to worry about the bevel now. I knew about the trick with the marking pen to see when you're done sharpening, but I didn't think of using that to check the bevel.

I just did it by eye - squinting on the side while adjusting the v-arm until it seemed like it's the right bevel. Of course during the experimental phase, when I was still trying to figure out how to use the jig, I'd forget to lock something down and completely ruined parts of the chisel because something moved towards or away from the wheel. How critical is it to maintain the right bevel with the turning tools?

Is 3500 rpm a slow speed grinder? I do have an 8". My wheels are 60 and 120 grit.

Anna

[Anna]

Jim, I have a few mm of brittle steel left to go. Since I'm now paranoid about ruining the chisels, I touch the chisel end to the wheel for just a few seconds before dunking it in water. It's taking quite a long time, but I guess it's my fault for not doing enough research before using my Sorbys as an experiment.

i'm sorry but i disagree that the chisels are ruined if you can locate a custom knife make or anybody with a forge you can have them re temper the steel and since there sorby chisels this would be the route i would go should cost very much

theres even away you can do this your self if you have torch oxy/propane or just a propane with a rosebud tip will work take a large scrap pcs of steel 3/4" thick heat till its red hot place your chisel on the heated scrap steel till it worms to a dull straw color or about 450 deg to 500 deg then dip it into mix of transmission fluid and bacon grease
leave for about 45 seconds then place back into the mix till it cools completly that will reharden the steel to retemper the steel all you have to do is bake it at 250 deg for 1 hour

B, sorry, can't help but laugh. You're talking to someone who's just getting over her fear of turning her noisy bench grinder on, and you want her to use a propane torch? Even if I had one, it'll probably take years before I get the nerve to even try it. Still good information, though. Thanks.

Anna

[Ken Massingale]

Ken, I think it's too late to worry about the bevel now. I knew about the trick with the marking pen to see when you're done sharpening, but I didn't think of using that to check the bevel.

I just did it by eye - squinting on the side while adjusting the v-arm until it seemed like it's the right bevel. Of course during the experimental phase, when I was still trying to figure out how to use the jig, I'd forget to lock something down and completely ruined parts of the chisel because something moved towards or away from the wheel. How critical is it to maintain the right bevel with the turning tools?

Is 3500 rpm a slow speed grinder? I do have an 8". My wheels are 60 and 120 grit.

Anna

IMHO, yes, the bevel angle is important. Are these roughing and/or spindle gouges? Measure the length tip to tip and I'll see if I have some about the same length and send you the distance to set the handle rest of the jig. It should be close enough to get you back to a starting point..

1750 is the slow speed grinder speed, but don't fret. Most folks prefer 1750 but actually Oneway/Wolverine show calculations that your 3500 is best.

[Anna]

Ken, I have 3 gouges, but I have no idea what the difference is between a bowl gouge and a spindle gouge. I know that the big one is a roughing gouge because someone told me.

The lenghts and widths are:

1. 6 1/8" by 1 inch - I think this is the roughing gouge. From the tip to the end of the bevel is about 3/16" right now. I also blued the edges a little bit, and I don't know how much I've departed from the original bevel. With this, I just used the v-arm to sharpen it.

2. 5 3/8" by 1/2" - The total length is actually 7 inches, but there's a solid portion of it in the bottom. This is the truly damaged one because I tried the vari-grind with it, and didn't know I was supposed to lock it from the top. Can't even begin to describe the bevel.

3. 4 5/16" by 3/8" - Like the previous one, it has a solid 2" in the bottom. I think this was a spindle gouge, but I can't remember anymore. Bevel's all messed up as well.

So glad I didn't try the skew attachment yet. I think I need further instructions somehow before I ruin the rest of the set. By the way, does a parting tool need sharpening as well?

Thanks for any help.

Anna

[Ken Massingale]

Ken, I have 3 gouges, but I have no idea what the difference is between a bowl gouge and a spindle gouge. I know that the big one is a roughing gouge because someone told me.

The lenghts and widths are:

1. 6 1/8" by 1 inch - I think this is the roughing gouge. From the tip to the end of the bevel is about 3/16" right now. I also blued the edges a little bit, and I don't know how much I've departed from the original bevel. With this, I just used the v-arm to sharpen it.

2. 5 3/8" by 1/2" - The total length is actually 7 inches, but there's a solid portion of it in the bottom. This is the truly damaged one because I tried the vari-grind with it, and didn't know I was supposed to lock it from the top. Can't even begin to describe the bevel.

3. 4 5/16" by 3/8" - Like the previous one, it has a solid 2" in the bottom. I think this was a spindle gouge, but I can't remember anymore. Bevel's all messed up as well.

So glad I didn't try the skew attachment yet. I think I need further instructions somehow before I ruin the rest of the set. By the way, does a parting tool need sharpening as well?

Thanks for any help.

Anna

Anna,
have you seen the Wolverine 'how-to' videos?

http://oneway.ca/multi-media/wolverine_videos.htm

I'm going to PM you on the chisel sizes.

[rja]

Anna:
If your turning chisels were carbon steel I would say you probably drew the temper in them since carbon tool steel is tempered in the 350 to 450 degree range. Your turning them blue indicates that you heated your tools higher than that. But since your tools are high speed steel, which are commonly tempered in the 800 to 1000 degree range, you have not likely ruined them.

[guycox]

Anna:
If your turning chisels were carbon steel I would say you probably drew the temper in them since carbon tool steel is tempered in the 350 to 450 degree range. Your turning them blue indicates that you heated your tools higher than that. But since your tools are high speed steel, which are commonly tempered in the 800 to 1000 degree range, you have not likely ruined them.

Gottta agree with rja - HSS will still be good .. Back in March I had two days with Lyle Jameison -- http://www.lylejamieson.com/ -- I learned a bunch - One of the things that I picked up was not to quench the HSS in water - it causes micro fractures at the edge..

The bottom line is that once the bevel is re-established, you'll only need a swipe or two to bring the edge back up.

I also hone the inside of the the flute with a tapered diamond hone. It makes a LOT of difference. I can most often start sanding at 150 grit even for something soft like cedar.