Grinding Wheels
 

I am considering white Norton wheels from Lee Valley or Blue slowspeed
wheels from Oneway. Which stones are preferable for woodturning chisels
and why are they preferable?

I used the white wheels and found that they wore and grooved far too quickly
for my tastes. Now I use a regular aluminum oxide wheel, 80 grit. I think,
and it is only my personal opinion, that any of the regular commercial
wheels have a fiable enough bond for good turning use. I have not used the
blue wheels. Note that the white, blue, etc colors are just a manufacturer's
coding system. The cutting material is still aluminum oxide.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

There is a lot to the selection of grinding wheels. Aluminum Oxide
comes in three or four basic colours - brown, blue and white. White
is more friable (each crystal breaks off more easily) than brown while
blue is in between. A grinding wheel consists of the material
(Aluminum oxide or silicon carbide), the grit, the hardness, the
structure and the type of bond (vitreous or resin).

The harder the material that you want to grind, the more friable you
want your wheel to be. When a grain becomes dull, you want it to break
off and expose a new sharp surface. If this does not happen the wheel
will glaze over and will not grind anymore. Thus white aluminum oxide
will be suitable for harder material while brown aluminum oxide will be
okay for softer material such as mild steel. Silicon carbide will be
suitalbe for non-ferrous material such as aluminum. Similarly you have
to choose the right hardness for the wheel and the right structure.
Too hard a wheel will tend to glaze if the material ground is also
hard. You will mostly use vitreous wheels for you grinding jobs.
Resin based wheels are good for applications such as cut-off wheels.

You may want to do a google search. I suggest entering a topic such as
"Brown vs White Aluminum oxide". You should come up with a lot of
information

Chip

Chip
I believe that if you check you find that Aluminum oxide is a white
crystalline substance and the various colors that are for sale are added by
manufacturers for proprietary classification purposes.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

Hi Darrell

I have worked in the metal industry and I do know that there are at
least half a dozen different grinding wheel colors, and yes there is no
standard as to exact hardness and friability between different
manufacturers, but there is a general labeling standard on grit,
material and hardness etc. and wheel colors are also indicative on bond
strength/hardness, I have a nephew who makes his living in an R&D lab of
a large electronics co. as a fine machinist and grinding as his
specialty, and his take on the wheels he uses is that you really have to
know from which manufacturer the wheels are, and experience has taught
him they are not all the same, 2 wheels with the same color, grit size
etc. and from different manufacturers makes for 2 different grinding
characteristics.

I have a link here to some more info if anyone is interested

http://www.jjjtrain.com/vms/other_grind_wheels.html#8

Have fun and take care
Leo Van Der Loo

Darrell Feltmate wrote:
Chip
I believe that if you check you find that Aluminum oxide is a white
crystalline substance and the various colors that are for sale are added by
manufacturers for proprietary classification purposes.

"Leo Van Der Loo" wrote in message

I have a link here to some more info if anyone is interested

http://www.jjjtrain.com/vms/other_grind_wheels.html#8

Thanks for the link, Leo. Excellent--best and most concise treatise I've
seen.

Max

In article .com,
wrote:

I am considering white Norton wheels from Lee Valley or Blue slowspeed
wheels from Oneway. Which stones are preferable for woodturning chisels
and why are they preferable?

You're going to make me dig out my catalogs, aren't you?

OK, the Lee Valley look good - especially at 1/2 or just under the
prices of the Oneways. My concern going with just these wheels is that
they don't have one coarse enough (80/120) from my experience. I use a
36 grit for reshaping the edge profile and an 80 grit for general
sharpening. (I use Camel brand from Woodcraft and they happen to be
blue.)

The Oneways look good too and I'm sure are top quality as Oneway
products are known to be. (Lee Valley also carries excellent products,
but they certainly aren't geared solely to the turning crowd with these
wheels like Oneway is.) I like the grits offered better than the LVs -
54/80/120.

If those were my two choices for sources and I had the budget, I'd
probably try the Oneway wheels in 54 and maybe 120. They offer a 90 day
satisfaction guarantee, so if the 120 proved too fine - meaning it
loaded up too fast for my grinding technique - I'd exchange it for an 80
grit.

Now that I've typed all that, I must say that I like my Camel wheels
from Woodcraft, and at about $25-$30 they seem to fall right in between
the two outlets you're considering.

--
"Sure we'll have fascism in America, but it'll come disguised
as 100% Americanism." -- Huey P. Long

I'm going to make a comment here that is not exactly in line with the
question asked. You have to look at wheels and even gouges as consummables;
both will wear awa;y if you are using them. If you avoid shaping and
sharpening because you don't want to wear them out you are missing the point
and maybe the fun.
billh

wrote in message
oups.com...
I am considering white Norton wheels from Lee Valley or Blue slowspeed
wheels from Oneway. Which stones are preferable for woodturning chisels
and why are they preferable?

Why are they knocking us using aol off the ng?
Glenn Hodges
Nashville, GA

Hi Ghodes2

It's not service that's important to them, you should know !!
It's MORE MORE MORE, money is the only drive.
Just make sure you keep that in mind when spending your money on so
called "service providers".

Have fun and take care
Leo Van Der Loo

Ghodges2 wrote:
Why are they knocking us using aol off the ng?
Glenn Hodges
Nashville, GA

Chip wrote:

: The harder the material that you want to grind, the more friable you
: want your wheel to be. When a grain becomes dull, you want it to break
: off and expose a new sharp surface. If this does not happen the wheel
: will glaze over and will not grind anymore. Thus white aluminum oxide
: will be suitable for harder material while brown aluminum oxide will be
: okay for softer material such as mild steel. Silicon carbide will be
: suitalbe for non-ferrous material such as aluminum.



You bring up aluminum. There is a post at Lee Valley's website, stressing
that you should never grind steel and aluminum on the same wheel.
It apparently can create thermite, and the result can be an exploding
wheel.

-- Andy Barss

Hi Andrew

Good call

I guess most of us have heard of termite and its use to weld rail tracks
and other large pieces, when mixing very fine aluminium and iron oxide
you make a 3500 degree C. flame and its essentially a flash.
It will in my opinion not explode the wheel, however it will give you a
scare as the compounds on your bench suddenly flare, and there is a good
potential for a fire in the case of us wood turners/workers with all the
shavings around.
I have a link to government site if interested.
http://www.hanford.gov/lessons/sitell/ll01/2001-36.htm

Andrew Barss wrote:

Chip wrote:

: The harder the material that you want to grind, the more friable you
: want your wheel to be. When a grain becomes dull, you want it to break
: off and expose a new sharp surface. If this does not happen the wheel
: will glaze over and will not grind anymore. Thus white aluminum oxide
: will be suitable for harder material while brown aluminum oxide will be
: okay for softer material such as mild steel. Silicon carbide will be
: suitalbe for non-ferrous material such as aluminum.



You bring up aluminum. There is a post at Lee Valley's website, stressing
that you should never grind steel and aluminum on the same wheel.
It apparently can create thermite, and the result can be an exploding
wheel.

-- Andy Barss