Taking off a lot of stone - How to?

[Komitadjie]

So, question that I haven't seen answered around here, at least not as far as I can find using the search tool:

If I want to remove ~3/8" of my SG-250 wheel's diameter in the fastest, most efficient way possible, how should I go about it?  Now, after you're all done getting your tongue back out of your throat, and breathing properly again, let me explain.  When I purchased my T-8, I did so as a "used like new" on Amazon.  When it arrived, UPS had knocked an unholy gouge in the corner of the wheel, with a club-mark that punched right through the cardboard box.  Unfortunately, it was not anywhere near adequately packed to survive the trip, so UPS would have laughed at an insurance claim.  I contacted the seller, and they immediately offered me a significant partial refund of the purchase price.  The deal I got for it to begin with would have most of you other T-8 owners grabbing something off of your bench to throw at me, so I was entirely fine with that.  I accepted his offer, and purchased a SB-250 to replace it.  I've been using that now for several weeks with great success on my chisels and knives. 

However, I keep looking at that 10" diameter SG-250, and going "gee... there's 9.5" worth of perfectly good grindstone there, with only that little ding...

So I figure if I can cut off 3/8 to 1/2" of the OD, I'll have a second perfectly good stone with 75% of its life left, essentially for free!  I can't imagine doing it with the stock truing tool, that'd take about a billion passes and probably eat the entire grading point... 

[grepper]

Observing the damage, it almost looks like if you just removed some of the surface so that the surface was flat, you might not notice the chip in the edge while sharpening.

It looks as if where it is bashed in has caused a bump in the surface.  I'm sure you would notice that, but maybe, just maybe, if you you removed just enough to flatten the surface it might work?  I'd at least give that a try before taking more desperate steps.

Hopefully someone else will chime in with ideas on how to remove a bunch of stone.

[Elden]

 
  I agree with Mark (grepper), take as little as possible off to obtain satisfactory results. I personally have used a cracked SG-250 successfully for quite sometime.  The truing tool is designed to hold up to the job. There are are hand held diamond truing tools available as well.

[Ken S]

3/8" off the diameter is 3/16" off the radius. I would either try Elden's suggestion to try using it as is or plan to use some of the money the seller refunded to order a spare diamond tool or two for the TT-50. Be patient.

Ken

[Komitadjie]

Sounds like "use as is" is the winning candidate here!  It trued up just fine and sharpened several chisels for me before the SB-250 came in, so I'll call it good and just use it the way it is. 

[Ken S]

I would combine Elden's "use it as is" plan with very regular and slightly heavier than needed truing. You will soon be where you want to be and be very skilled with your truing tool. That's a goid thing.

I predict you will be very careful when moving your grinding wheels! 

Ken

[Komitadjie]

Ain't that the truth!  With as well as this works, I'm probably going to want the Japanese waterstone at some point as well.  This really is a sweet system. 

Next up, gotta get that drill bit jig, I think!

[grepper]

I would not just use it like it is, but rather, at least try smoothing the surface with the truing tool so there is no bump where the damage is.  That might be good enough. 

[Rem]

If you're inclined to remove some stone, I'd go for it.   I've done a couple of fairly nasty gouges and it goes faster than you might think.  Make a few passes and see what you think.  You might be surprised.  R

[Ken S]

Good post, Rem.

Ken

[SharpenADullWitt]

Certainly the use it as is category is what I am in.  I gave my father the old stone from my machine, that the former user dropped and chipped.  He uses it on a clone, and it is better IMHO then the stone that came with that.  He did use the truing tool to get it down some, and he uses it in the fine grind more, where I would have used it as the 220 stone and used the new one that came with mine, as the fine grind stone. (no changing of grades)
I have done knife blades over there, where your taking them across the stone and you really don't even notice it.
While this isn't a high speed grinder, I would still recommend wearing safety glasses though.

[Herman Trivilino]

I would use the chipped grindstone for rough work, such as lawn mower blades and other garden tools. Perhaps even wood chisels if you do the kind of rough carpentry I do. Save your good grindstone for your kitchen knives, pocket knives, and other fine work.

[Komitadjie]

I trued it up, and it seems to work ok.  There's a distinct and rather alarming slamming of the truing tool as it goes over the chip, but that's about it.  I think I'll definitely keep it around as a backup to my SB-250, for rough work I turn to the dry grinder, or more commonly my Kalamazoo Industries belt grinder.  THAT thing peels off the steel! 

At some point, I think I'm going to get the dry-grinder mount for the Tormek jigs, and see if I can adapt it to work with the Kalamazoo.  That would really be something, do the rough shaping on the Kally with a 32 or 60-grit ceramic belt to take the metal off really fast without building heat, then go over to the Tormek to do the final sharpening and polish up the bevel...  I do a ton of knife sharpening on the belt with great results freehand, so the entire guided sharpening thing on a power tool is a bit new for me. 

[Ken S]

Try taking a very light cut when you are truing, only half a number on the microadjust.

Also, having to do more truing will help you become fluent with this essential Tormek skill.

Ken

[peterpig]

Hi Kala......  before you buy that jig for bench grinder - TRY TO MAKE ONE ! All you need is a right size channel iron - big enough to bolt the horizontal post holder on it- drill on it corresponding holes and by using off-cut wood and Bob's your uncle ! Look at that jig and you'll realize how simple it is - I'm about to start making one for myself !