Flattening chisel faces on waterstones sides

[Haitham]

Hello

In the HB-10 manual and in some videos is explained
that the side of a SG-250 (Tormek T8) could be used
to flatten the face of a chisel or plane blade.

My concern is that if I start to do it as an habit I would eventually affect
the width of the stone that is 2 inches wide out of the factory

Thank you, Haitham Jaber, Rome

[Ken S]

Welcome to the forum, Haitham.

The real issue with using the SG grinding wheel to flatten the backs of chisels and plane irons on the side of the grinding wheel is that eventually, after a lot of use, the side of the wheel will no longer be flat.

Wear to the thickness of the wheel should be minimal and not really a problem.

Flattening and polishing is normally one and done. How many chisels and plane irons do you plan to flatten and sharpen? If you are maintaining just your own tools, I suspect half a dozen of each should cover your needs. These won't put a strain on your grinding wheel.

If you plan on maintaining a lot more tools, shuc as for a busy cabinet shop or school, please reply and I will post some thoughts.

Keep us posted.

Ken

[John Hancock Sr]

after a lot of use, the side of the wheel will no longer be flat

Tormek warn against using the sides of the SG wheel. But, really there is no need. The concave on the chisel or plane irons is very small indeed if that is what you are worried about.

[Haitham]

next message is the right one... sorry i posted two times

[Haitham]

Thank you very much,

I think that if this is the case I will use it ever so often, so I shoudn't  worry about it I guess.
Any way if in the future I will want to start using the side of the wheel I will buy
a Diamond wheel. That raises another question that is about the coarsness of the wheel.
Which is a Diamond wheel that matches the grit of the T8 original waterstone?
I see in some videos that carver's knifes and the like are sharpened with finer diamond stones.

Thank you

[John Hancock Sr]

Which is a Diamond wheel that matches the grit of the T8 original waterstone

The DC is about the same as the rough graded SG and the DE is about the same as the fine graded SG. The DF is about half way between (600G). For cheap knives I don't go any finer than the DF since there is not a lot of point. But quality knives I will spend the extra and take them to DE.

[Haitham]

Thank you very much John

[Ken S]

I have not heard anything about it lately; however, we used to hear about
"600 grit" with the SG grinding wheel. The 600 number is just an approximation, really meaning  an in between grit. The SG is not a 220/1000 two grit only stone.
we can vary the grit by just varying the time with the stone grader. Remember, this is not an exact science.

Ken

[Haitham]

Thank you Ken!

[John Hancock Sr]

Remember, this is not an exact science

And there you have it. Grit is an extremely complex science. There are different standards and even then a grit is simply the average size of the grain. The number is meant to represent the size sieve that the particles will fall through. So when you say 600G it depends on which standard you are referring to (mostly they don't say but in Tormek's case probably ISO) and even then it is a range where there is overlap between adjacent grits. This is probably why Tormek prefer the coarse/fine/extra fine nomenclature.

If you want your mind blown just look here https://www.gritomatic.com/pages/grit-fundamentals and scroll down to the "Gritomatic" chart. In the early days it was like the wild west but it has now pretty much settled down to a few familiar standards, but still many persist.