Stone Grader

[abbott013]

Not long owned my machine. The surface of my stone grader has become shiny, and I am now wondering how affective it is at grading the waterstone. Have I been using to much pressure on the stone grader to cause it to become shiny on the course side. Any help very welcome.

[Ken S]

Welcome to the forum, Martin. Two ways to tell if your stone grader is still working effectively:
First, feel the grindstone while it ts runnung. The grindstone should feel like glass after using the stone grader fine side and rough after using the coarse side of the stone grader. related to this, you should also hear a difference. Graded fine, the grinding should sound quieter.

Second, try grinding the "standard" three quarter inch (19 mm) bench chisel. Look carefully at the scratches left after grinding with the wheel graded coarse. The grade the grinding wheel fine and grind. If the scratches left are much finer, your stone grader is doing its job.

As to the shinyness, I am traveling for a few days and am unable to look at my stone grader. Hopefully some of the other forum members will chime in. I suspect most of the stone grader replacements are due to being dropped on concrete floors. Abrasives are very hard and therefore brittle. They usually last a long time.

Ken

[grepper]

I've not heard of the stone grader becoming shiny before, especially the coarse side.  Not to say it's not so, just never heard of that before.  Maybe someone else has had that happen.

Try using the edges of the stone grader.  That can be very effective.

Also, try using the short edge of the grader, so that you are holding the stone grader with the long side parallel to the wheel.   You can get a lot of extra life out of it by using both ends.

[Rick]

My stone is doing exactly the same thing. Looks as if its getting polished. I was wondering if the grading stone can be reconditioned?

[Rob]

Grade the grader....I like that...sounds like a product opportunity Tormek...$50, $60 a hundred...what do you think.  No of course, you're right....$800 and you get a "free" T7 with every one :-)

The new PI55-Taker diamond grader-isation-aliser. No shop should be without one (or three)

[Rick]

I just thought taking it to an 80 grit might take the shine off and give it more teeth! Anyhow, its nice and shiny now!

[Herman Trivilino]

My stone is doing exactly the same thing. Looks as if its getting polished. I was wondering if the grading stone can be reconditioned?

Use the corner of the stone grader and apply lots of pressure.

[Rick]

That's what I'm doing Herman, but I don't think that the grader should glaze over as this is an important tool for the obvious reasons.

[jeffs55]

I wonder if you are sharpening or grinding some really soft metals on the Tormek and the residue is clogging the grader? In any case, I would suggest using a wire brush and hope for the best. Although you might take the diamond dressing tool and see it you can do something with that. I would simply rub it vigorously all over the grader. You should know that I have no experience with this problem and am just throwing out suggestions of what I would try.

[Rick]

This all started when I tried to sharpen DeWALT planer blades with the SB-250. I found that the stone glazed over rather quickly (about 20 revolutions) requiring frequent grading. If you have a slightly damaged blade DO NOT try to re-edge it with the T-7 and the SB-250 unless you have a few hours to waste. Best scrap the blades and buy a new set. Now I need a new SP-650. Very frustrating considering the cash spent on this equipment.

[Rob]

been there...got that T-shirt.  Planar blade jig...rubbish!

[Rob]

the SP650 isn't ruined though.  The surface is meant to wear away slowly so you can persevere with it and it will work on the grindstone.  You really need to lean on it, don't be shy with the weight, you wont hurt the Tormek.  You could try roughing the 650 with one of those T shaped diamond dressers just to take the skin off so to speak but you shouldn't need to.  Just give it some welly on the grindstone.

Your problem isn't the sp650, its grinding anything with a large surface area that has very hard metal.  All HSS fits into this bracket and some planar knives are even more exotic alloys which are incredibly hard.  The planar jig/Tormek combo are simply not up to the task of grinding those difficult metals.  I went through all this myself with Startrite 12" planar knives. I had to grade it so often that the wheel was sufficiently reduced in size to throw off the precision settings of the jig!!

[Ken S]

"Planer blade jig...rubbish"

The most experienced Tormek user I know successfully uses the planer blade, both with the Tormek and with another sharpening system. I agree that the are difficulties sharpening planer blades with the Tormek. I do not know if the difficulties are with the grinding wheel and high speed steel or with operator technique. Jeff Farris wrote very little about the SB or the planer jig. Sweden has not published much about either. My gut feeling is that the jig is OK. I do not have enough knowledge about the area to know, nor have I sharpened any planer blades. My tests with the SB have left me frustrated with it.

Someone please enlighten me.

Ken

[Rob]

Ken I appreciate your enthusiasm for all things Tormek but genuinely struggle to understand how you can come out in support of a component you haven't used??

I sense where you're coming from is perhaps related to Ionut's comments?  But you also cite Jeff Farris' noticeable silence on this particular jig.  Surely you must all realise that it was because Jeff is an honest bloke that he never commented on the jig.  He "knew" it basically only works half the time and then only with very soft metals, so to avoid having to tell "porky pies" (cockney rhyming slang for lies) he just remained tacet, thus avoiding any conflict.  I always felt that reading between the lines of Jeff's very tentative comments about the planar jig that he had no faith in it.  My experience (with very hard steel) absolutely bears that out.  Recall it took me 8 hours to grind my 3 knives and even then was unable to remove a ding.  The stone glazed over so fast, one spent the whole time regrading the stone.  There's no operator error involved in the stone glazing, it was clearly cutting but the qty and hardness of the steel were too much for it.

Honestly, I really hate to be the one that bursts your extremely exuberant about Tormek bubble but the planar jig is simply not fit for purpose.  I feel if you analysed all the planar jig comments scientifically you'd find more frustrating fails than significant successes.  Ionut being the obvious good one but then he isn't your average punter, he's a highly skilled, engineering minded "veritable inventor" and I imagine few problems will prevent him from seeing a creative method round the obstacles.

Ironically, the jig isn't the problem, the jig is another triumph of Tormek design.  The problem is the grinding medium.  Yet again (my hobby horse I know), the problem is that the Tormek system is not good at removing a lot of steel when it's hard and large in surface area.  If such a thing as an industrial diamond wheel existed then we might have a solution!!

The challenge is that the wheel glazes too quickly, stops cutting leaving one with the dubious pleasure of either leaning on the SP 650 literally every minute or so...or trying to get even more aggression into the wheel, truing it with the diamond dresser.  That causes sufficient wheel wear to throw out the very precise jig settings.  The wheel wont cut for long enough to get through the job.

[Herman Trivilino]

I think the issue is, as Rob said, large surface areas of exotically hard high-speed steels (HSS). There is no tool with universal applicability. Somewhere along the way we all meet our match.

I also agree with Rob that the stone grader is not ruined by the glaze. Mine's been that way for many many years and it still works just fine. Sorry for the pun. It works just coarse, too.