When to replace stone?

[Brad I]

I've had a T-3 for 5 years or so.  It has always done a good job. But the stone is worn down to about the same size as the leather strop wheel.

When is a new stone replacement a good idea?

[Herman Trivilino]

My honing wheel has a diameter of 215 mm.
The scale on my Tormek goes down to 190 mm.
The scale on my angle master goes down to 150 mm.

I'd say you've got plenty left.  My original grindstone broke at 200 mm, so that's as small as mine has ever gotten. 
(You can read about it here: http://forum.tormek.com/index.php?topic=929.)

The only thing I'd note is that as the grindstone gets smaller the hollow grind you get on the bevels you grind will be more pronounced.  If this is not an issue for you, and I don't see why it would be, then you can probably get a lot more life out of your grindstone.

[Brad I]

Are you on a T-7?  My honing wheel is about 140 mm. My stone is about 152MM if I've done the conversion right. (Currently 6inch diameter on stone)

My angle master stops at 150 too.  I don't use it too much anyway, but is that a good measurement for stone life?

I don't mind a mild hollow grind, unless it gets too dramatic.

Thanks

[Herman Trivilino]

Oh, yeah.  Sorry, I hadn't noticed that you have a T3.

[Herman Trivilino]

My angle master stops at 150 too.  I don't use it too much anyway, but is that a good measurement for stone life?

That was really just a guess.  Is there a scale on the side of the T3 that indicates the grindstone diameter?  If there is, I'd go by the smallest number on that scale, but again that's just a guess.  As long as it's still working I'd keep using it.

[Ken S]

I like the thought of using a veteran wheel for rough jobs and using a newer wheel for more precise work.

Ken

[jeffs55]

I would say that the time to replace the stone is directly related to the amount of hollow grind that you can tolerate (or that the device can tolerate and still function as designed) on any given object. Clearly, there is a limit on how much can be tolerated on a certain edge and still be useful. I would imagine that a scalpel would be the last object to be sharpened on a small wheel as it could stand to be as sharp as possible. That same edge would be practically useless on a kitchen knife. In short, it is determined by aesthetic  as well as funtional issues and you are the judge.

[Herman Trivilino]

You're right, Ken.  It's kinda weird sometimes when after I just got done sharpening a mower blade I have to sharpen a good kitchen knife.  It just doesn't seem right to be chopping vegetables with something that came that close to mowing the lawn. 

It's also nice to have a back up in stock in case one of them breaks.

[Rob]

I like the idea of a vet wheel too....a sort of gnarled....did 3 tours in Vietnam type wheel......all leathery and lined....sort of like Jack Polance :-)

[Rob]

Another thought....wouldnt the wheel get so small that its diameter would cause it to fail making contact with the water trough?

[Ken S]

Herman, it's all part of the food chain........

Rob, I would put that veteran wheel next to a really beat up Nikon F on the shelf.  Whoever entered the shop would know a serious person worked there.  Park a rugged old Land Rover on the lawn, and you would have the whole package!

Ken

[Rob]

 

[Brad I]

Another thought....wouldnt the wheel get so small that its diameter would cause it to fail making contact with the water trough?

I believe it would.  Currently, my stone dips into the trough about a 1/2 inch.

[Elden]

Another thought....wouldnt the wheel get so small that its diameter would cause it to fail making contact with the water trough?

Rob, I read somewhere about someone setting the water trough  on a block so as to raise the water level for a small wheel.

[Herman Trivilino]

Another thought....wouldnt the wheel get so small that its diameter would cause it to fail making contact with the water trough?

I would say that's the definition of a wheel that's too small.   

Of course, you could always modify the water trough so that it would hold more water!