Author Topic: First chisel sharpening.  (Read 656 times)

Offline sharps

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First chisel sharpening.
« on: October 27, 2019, 01:02:57 pm »
Despite buying my used Tormek 2000 a couple of weeks ago I resisted the temptation to play with it until I had finished my workshop. Now it is firmly bolted down on a steel pedestal I found locally, so I soaked the wheel and proceeded to true the wheel. There was 245mm left on the wheel, but it needed nearly 1mm taken off to flatten it, but the t50 tool did a good job.
I found a bunch of old rusty chisels (not my fault, I rescued them from a skip), wire-wooled one and set it in the jig, then used the angle finder to set it at 25°.I used the grading stone to coarsen the wheel up and proceeded to grind away. The chisel's edge had a large chip in it, probably over 1/2mm, so I understand there was a lot of metal to take away, but I was surprised how long it took. I re-dressed the stone with the block every ten minutes, but it took me over half an hour before I was ready to polish it with the fine wheel. Is this normal? Should I be using the grading block more often, or applying a llttle more pressure to speed things up? I was pleased with the result, the chisel is now shaving sharp, though when I looked at the edge under my microscope I noticed tiny imperfections, which I realise are caused by the rust-pitting in the steel, no matter, it's just for practice.
I probably shouldn't have tried such a badly damaged tool, but need reassuring I'm doing things right.I certainly wouldn't have wanted to put that on a bench stone!

Offline john.jcb

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Re: First chisel sharpening.
« Reply #1 on: October 27, 2019, 03:08:44 pm »
In my opinion a very badly damaged tool should be repaired on a low speed belt grinder if you are looking to speed up the process. Your other alternative is to buy a coarser wheel for the Tormek. I believe our moderator Ken has tried alternate stones and perhaps he can add his thoughts.

I recently repaired a chisel and like you it took some time.

Offline sharps

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Re: First chisel sharpening.
« Reply #2 on: October 27, 2019, 05:24:08 pm »
Thanks, I couldn't see I was doing anything wrong, nice to know that sort of time is normal. I've got a crappy bench grinder which I could use to take off most of the metal, but I don't trust myself to keep the edge cool, certainly wouldn't try it on my knives.
I didn't see it with my eye but the chisel is also a smidgeon off square. Not enough to worry about, at least for me. I notice the new straight edge jigs have micro adjustment knobs, mine just clamps the tool.

Offline RichColvin

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Re: First chisel sharpening.
« Reply #3 on: October 27, 2019, 05:31:47 pm »
Richard,

I bought a BGM-100 (https://www.tormek.com/usa/en/accessories/other-accessories/bgm-100-bench-grinder-mounting-set/ ) so I could use my traditional grinder for gross shaping / metal removal.  Works well as the standard Tormek jigs can be used for that, & then sharpen on the Tormek machine.

I also found that the course diamond wheel makes light work of this.  But that’s a much different cost than the BGM-100.

Kind regards,
Rich
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You are born weak & frail, and you die weak & frail.  What you do between those is up to you.

Offline sharps

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Re: First chisel sharpening.
« Reply #4 on: October 27, 2019, 08:57:56 pm »
That tool looks the business, but I'm going to have to make do at the moment, and I'm thinking once I've restored everything around the place perhaps I won't need too much grinding. After you mentioned the diamond wheel I realised I would probably been better off with my 8x3 coarse diamond stone and honing guide, but that doesn't teach me the Tormek. To be honest I'm itching to get on with my knives, but I'll do another chisel first, I have a 1 1/2" Marples with only surface rust and minor edge knicks. Hopefully that will be 100% square- the first attempt was a half inch chisel, and I've read narrower chisels are harder to square- hence the micro-adjust knobs on the new jig?

Offline Ken S

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Re: First chisel sharpening.
« Reply #5 on: October 28, 2019, 03:09:14 am »
Sharps,
You are off to a good start. I worked on a turning skew chisel which shed some light for me on a situation like yours. I had intended merely to sharpen it. Foolishly I thought the skew and bevel angles would match the presets on my turning tool setter. Neither was a match. Both seemed close enough that I decided to soldier on. I was surprised how much metal needed to be removed and how long it took to reshape my skew.

(In wiser hindsight, I should have checked both angles and gradually reground them to conform with my setting tool.)

A couple suggestions for your damaged chisel: In this case, I would use the TT-50 traversing the stone much more quickly. Perhaps thirty seconds. This produces a less smooth surface on the grinding wheel which should grind more quickly.
Before standard grinding, grind off the damaged area holding the chisel at 90°. I would suggest checking for square at this point and later as well. Check for square and course correct early enough that you don't get far off course.

The TT-50 will keep your grinding wheel cutting more coarsely than the coarse side of the stone grader. You will feel and hear when your grinding wheel needs to be refreshed.

There are faster cutting grinding wheels in diamond, CBN, or the Norton 3X. These all work. However, If you keep your grinding wheel well dressed and are patient, your SG will get the job done. I would factor in how often you need to do reshaping or repairing major damage. If you do a lot, the extra investment is well returned in time saved. For essentially one time repairs on two or three chisels, my thrifty self would at least try using the SG.

Unlike the other Tormek grinding wheels, you can safely use a lot of grinding pressure with the SG. A major regrind will take enough time for you to really learn about how to use your Tormek and SG. Use this time wisely!

If you read the tips and techniques topic I started (now frozen as the first topic), You will find that I prefer to s
learn on medium width chisels. Narrow chisels can be difficult.

Do keep us posted!

Ken

Offline sharps

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Re: First chisel sharpening.
« Reply #6 on: October 28, 2019, 07:23:49 am »
Thanks Ken, I will try coarsening the stone up with a faster pass with the truing wheel. Also, I'm wondering if I was applying enough pressure, for long enough, with the grading stone.
I'm going to take the time to read the advice in the appropriate sections here, already I've realised I had too much of my chisel protruding from the jig-(probably 80mm), which may account for the edge ending up very slightly out of square- that and the fact it was a very beat up tool, judging from the paint on the handle it had been used for opening tins. (not guilty!!)
It's all too easy to watch all the videos and think you know it all, if I can get my tablet unstuck off my boat (where I use it for navigation) I will take john.jcb's advice and take it to my machine, and watch it bit by bit, as I work.

Offline sharps

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Re: First chisel sharpening.
« Reply #7 on: October 29, 2019, 02:53:56 pm »
I've just sharpened another Marples chisel, the same size as the last (3/4"), but in much better condition, with only slight chipping to the edge.. A good rub with the coarse grading stone (don't think I used it enough on my first attempt, I should have felt the stone), and gave the tool a couple of passes, which damned near cleaned the metal off. I fined down the stone, realising I probably didn't need to have used the coarse, and polished it up. I got rather hypnotised by the action, but ended up with a very shiny bevel. Gave it a go on the leather, which I've finally got how I like my strops, and it cuts really nicely. I did notice a very slight convex edge, but square if that makes sense. Maybe the slight curving is lifting on the return stroke across the wheel.? I was wondering if it is worth a beginner like me using a drill stop on the USB to stop the jig travelling too far- I admit to coming off the stone on my first attempt, and my concentration can lapse!

I'm afraid I'm one for running before I can walk, and after my chisel success I couldn't resist trying a knife. I found a 4" cheap lock knife of an easy steel and set it a 20°. I elected to work with the wheel going away from me,as  I'd heard it was more forgiving, if slower. I continued with the fine stone, as the existing edge wasn't that bad. I soon worked out how to keep the jig against the rail, and concentrated on lifting, not pulling, the handle as I approached the bend of the tip. I had been lucky in positioning the blade in the jig as the edge was perfectly even- using my Lansky I invariably end up with a much smaller angle on the tip. I worked the burr over a couple of times, nice and light the last time, made easy by the away wheel. I really enjoyed honing it on the leather, very therapeutic, what with the sound of running water by my ear! It ended up paper sharp, which is about as far as you want to go with cheap Chinese stainless. I will use the stone towards me next time, as the rest of my practice blades will need a good going at.

Sorry for the waffle,, I suppose the last part should have been in the knife section.

Offline jeffs55

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Re: First chisel sharpening.
« Reply #8 on: October 29, 2019, 08:35:09 pm »
The stone turning towards you is the way I do most things. Most things being knives or chisels which is all I have ever sharpened.  Be very careful and use a light touch. If the blade ever grabs the wheel, you are going to be scared to death.
You can use less of more but you cannot make more of less.

Offline Ken S

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Re: First chisel sharpening.
« Reply #9 on: October 30, 2019, 12:56:30 am »
Jeff,

I believe you have found one of the major success keys of using the Tormek. "Be very careful and use a light touch."

Well stated.

Ken

Offline sharps

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Re: First chisel sharpening.
« Reply #10 on: October 30, 2019, 06:39:28 am »
Yes, Although it only turns slowly it needs good concentration to watch what's going on. I have to admit I touched the bolster of my knife on the stone, not a disaster (at least not on a ten quid knife), but not what you want. It happened when using my left hand on the handle, I find it much harder to develop muscle memory on my left.

Offline rsetina

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Re: First chisel sharpening.
« Reply #11 on: November 16, 2019, 07:29:11 am »
Something to remember is that even though it may take a long time to get a chisel back into shape, once done, the resharpening and touch up of the same chisel will go very quickly the next time. All the major work would already be done.