Thread: The Blue Max and other wheels

Arthur

A good question.

I hope somebody replies soon.

Regards
Paul

Hi Chaps,
I don't own any of those Fandangle Sharpening Gadgets either.
So I have just used all these years, with 2 White Allum. Oxide Wheels. 1 is 60G. other is 120G.
I Sharpen by hand, & get a good result for me.
The thing is to keep the Wheels clean, & not to use the Centre of the Wheel, as you will have a Groove in it & makes it hard to Sharpen Skews.
Buy a Diamond Tile Cutting Wheel $9? & that will clean your Wheels.
Have fun.

That's all very well for some Issa.

I have always loved working with timber but came late to doing it on a "regular" basis. I have had many interruptions over the years and this lack of continuity and therefore, practice, leads me to have to use Jigs.

This simply makes me different, not inferior, to other wood working beings.

I also look at the fact that if technology gives me the result I want then so be it.

Where would most of us be without modern machinery, tool;s and jigs to help us on our way?

Would any of us want to use the crude files manufactured by the method and materials used in the times of da Vinci?? I suspect not!!

Exactly right. Same applies to edge management for wood carving tools.
There are several quite different methods.
They all work and they all produce the same result.
Most of what I still do is the substance of the "Star's Sharpening Journey"
thread in the Wood Carving Forum (caution! long and windy)

I'm convinced that the basic issue is to pick a method and learn it.
If things don't go right, figure out the reason why. Many was the night
that I quit in disgust, perpetually dull edges on particular carving tools.
Not even so dull as to need anything as crude as 800 grit.
I learned what to do.

Had a chat this morning with Tony from Wide Bay Saw Service.

I've dealt with him a little since I've been here and he is a fountain of information.

He informed me that there is more to wheels than meets the eye.

I already knew about different abrasive compounds in wheels and something of the different bonding agents used to hold the wheel together and just as importantly, to let the wheel wear as you sharpen.

What I didn't know was that wheels are graded for hardness using letters of the alphabet with A being the softest. So it is possible to get wheels with the most suitable level a combination of grit, bonding compound and hardness for a specific task.

I inquired about pink wheels and the softest pink he found was at level K which is only just below the L and M rankings of the grey wheels used for mild steel.

I wonder how many wheel users are really aware of the complex nature of the item they are using. I certainly was not!

On page 38 of Leonard Lee's book: "The Complete Guide To Sharpening" is the grindstone code.

The point which interested me the most is that grind stones can be made harder by increasing the amount of binder.
This is called the Grade. It's a letter in the approx middle of the code sequence.
The wheel lasts longer but tends to grind hotter because it retains more worn abrasive particles
than a softer wheel. The cutting rate is reduced as the friction increases.
ABCDEFG - very soft
HIJK - soft
LMNO - medium
PQRS - hard
TUVWXYZ - very hard

The pomp and ceremony about wheel problems might be due to a wheel with a practically useless texture for the task.

This also makes me wonder about the apparent witchcraft of making a muddy slop on a waterstone of ungraded and
smashed abrasive partices and expecting the stone to cut better. Horse puckey. If I use a 1000 grit stone, I expect
it to cut at 1K

White wheels are Aluminium Oxide (AlOx), pink wheels are AlOx with Chromium Oxide added, brown wheels are AlOx with Titanium Oxide added. If you heat treat the brown wheels, then TiO precipitates giving you blue wheels.
All these wheels can be had in various grain size and binder hardness (see RV post).
Larger grain wheels run cooler than smaller grain wheels but aren't as smooth.
Softer wheels run cooler than harder wheels as the wear to expose new grit, however they wear faster.
You can read more about it here: http://www.globalspec.com/SpecSearch...rinding_wheels

One way of running a cooler wheel is to put a slight crown on the wheel so that less of the tool is in contact at any point of time.

What type of metal are your tools?

Is it possible that the color might be attributed to the binder and not the abrasive?
AlOx is white, so is TOx (artists' oils and acrylics for example) and chromium (II) oxide
is a really insipid swamp green, made up as artisrs' color and honing compound bars.

As Arthur has stated earlier, there has been a lot of discussion over the sharpening process. I have been wondering too, is there a "new solution"? The chisels that Helmut organised and Ray G and Josh did the final process on were made of M2 HSS. The surface on the chisels was mirror finish. There is NO scratch marks from the surface grinding process just a shiny lustre to the surface. The grinding angle process they gave us was extremely sharp and ready to use (Well I started to use them) It made me wonder if with "new technology" that is available to us now, could we just grind a n edge on a tool and go straight to working with it essentially negating the honing process. My training in Carpentry, (40 plus years experience) tells me to grind an edge to remove any defects in the cutting edge then hone to get the desired sharpness needed. My training would have been very old even when I started the trade so that is why I am looking to see if it could be trained.
I PM'd Ray and Josh and asked them what wheels they used on their surface grinder that producedthe fine finish on the chisels. The wheels used were
CGW Camel AS3 - 30% Cubitron 20%Pink Aluminium Oxide and 50% White Oxide. From the search I did I found that those wheels are akin to Norton 3SG or 5SG. The time got away on me so I never finished my search to see if these wheels were able to go straight onto the 8" bench grinder. I am thinking that these wheels are very fine grained so can deliver a fine finish to the surface.

G'dayhiroller.

My tools are mostly HSS but a couple that came with the second hand lathe I bought are carbon steel.

This has turned into an informative discussion and I thank everyone who has contributed.

I guess we all have more to learn!!!

Sorry. "mirror finish" means only that our eyes cannot resolve the fine scratches left by the final abrasive.
Look at your result with a 20X magnifier. Steels are just so crappy soft. RC62 is piffle.

Look at the results in Leonard Lee's "The Complete Guide to Sharpening."
He had quite a few photomicrographs done with a Scanning Electron Microscope,
made in collaboration with the National Research Council of Canada.

A clean edge, at the level of electron microscopy will cost you more than $1,500 per mm of edge.
Bust the knife and sharpening will cost the same.
I did TEM and SEM for years without a mark at 40,000X

So, what can we all do to achieve the goal of smooth woods? A robust edge for workability
and fine enough to see a sheen.

Then, I read about all kinds of "fine" woodworkers who insist on smashing and shredding that
wonderfully cut/planed surface with sandpapers.
Smells like hippocrappy to me.

One of our site sponsors has a wide range of wheels available including Norton SG wheels.
http://www.thesandpaperman.com.au/grinding-wheels/

If you look at the white wheels there you can see white wheels have a code such as 38A46MVBE or 38A80KVBE or 38A60JVBE
Where the 46, 60 or 80 is the grit size and the J, M or K is the hardness of the wheel.

I use the Blue Max. It took a while to get used to as when I started I tended to be impatient. I tossed the tool rests which came with my grinder and use the Lee Valley Veritas rest which is bigger, easier to use and lots of adjustment.

The main thing I have found is that patience, for me, is the key.
Get the angle, place my thumb on the back close to the tip and keep the chisel sliding across the surface of the wheel. Yes, it is slow, especially when I get close to finishing the grind as it becomes slide and dip in water, wait a moment, slide and dip etc. The thumb on the back is the heat indicator as well as looking to avoid any blueing of the tip.

I find that I don't need to grind too often as the hollow grind is very easy to touch up on an oil stone as the chisel becomes dull - just a couple of passes on the stone and you touch up just the tip and the top of the grind and off you go again. When I used to flat sharpen - to touch it up I had to put it in the jig and redo the whole flat surface on the oil stone.

One of the "tricks" using the Blue Max is to keep it very clean using a wheel dresser - yes, it does "wear" the wheel but to me the wheel is sacrificial. I didn't measure the new wheel when I bought it but I can't see any real loss of diameter. A clean wheel cuts better and cooler. It is surprising as the wheel doesn't necessarily look dirty or clogged but the dresser makes a huge difference.

hiroller = thank you for that.
If wood workers buy the wrong wheels for the application they absolutely have no reason to gringe about it.
Learn to read the code! Don't knee-jerk this purchase, there's such a spectrum of wheels now that you
owe it to yourself to figure out what you need and find that one.
Don't believe that there will be any lasting damage to your intellect.