Obtaining Grinding Wheels

[Brian Littlewood]

Woodturning Grinding Wheels

I am a woodturner and need some help concerning grinding wheels, principally where to get the right ones. It's been a long time since I've been able to sharpen my tools. I now wonder if I've ever sharpened them properly! The story goes .....
I bought my lathe about 30 years ago and started collecting tools at that time. Amongst these was the grinder, a Black and Decker workstation with a wheel on the left and a chuck on the right. The machine has seemed useful for a long time and is still going strong. After a fairly long gap in my woodturning for various reasons, I started again a couple of months ago to turn a couple of dozen door knobs for my son and his wife. Decided to practice a bit in scrounged waste and fairly quickly decided that I couldn't get the tools sharp enough - they weren't cutting nicely and every now and again I got a catch with the skew on the beads and the gouge on the coves. So I looked on the internet and found loads of good advice on how to correct my techniques which I've been using to advantage with some success. But in amongst all this guidance were many comments on the importance of not using the wrong wheels to sharpen your tools. The wrong wheels being hard carborundum. Guess what wheel came on my Black and Decker grinder - one with a label BA46PV. Days of spare-time research on the internet suggested that this is an aluminium oxide 46 grit hard vitrified wheel,, not at all what I should have been using for the last 30 years! So I looked around for what I really need and eventually came to terms with the complexities of wheel composition and drew the conclusion that I must have a soft wheel (hardness I), aluminium oxide is fine but the grit should be around 80 rather than the 46 I've got. I know the size of the wheel, 125mmx13mmx20mm bore to fit on the Black and Decker and thought "here we go, here comes the easy part, go out and buy one". That was a week ago. I've tried all the tool distributors in my town. I've spent hours searching the internet. I've found hundreds of suppliers and thousands of wheels. I've discovered "new" wheel materials that promise super grinds on HSS and incredible lifespans at incredibly high costs. But can I find what I think I need, a white aluminium oxide wheel with a grit of around 80, an I (or so) bond and a size of 125x13x20? No. Nowhere. Has anyone got any suggestions please? Perish the thought but if I don't find a supplier soon I reckon I'll continue to use the wrong wheel just to get the job done. I really hope someone out there can guide me to a suitable UK supplier. I look forward to your responses.

Many thanks,

Brian

 

[woodyturner]

Have you tried Axminster http://www.axminster.co.uk/axminster-wi ... rod863380/

 

[paulm]

http://www.axminster.co.uk/axminster-al ... prod22227/

http://www.axminster.co.uk/axminster-gr ... prod29710/

Cheers, Paul

 

[nev]

http://www.peterchild.co.uk/grind/grindingwheel.htm

 

[jumps]

But can I find what I think I need, a white aluminium oxide wheel with a grit of around 80, an I (or so) bond and a size of 125x13x20? No. ............... I look forward to your responses.

Many thanks,

Brian

I don't think you will find one at 13mm width to replace the existing grey 'thing', and 150mm diameter is much more common....

As to 'white oxide' being the solution, I have both this and the Blue Micro Crystaline referenced here (and supplied by Peter)

http://www.peterchild.co.uk/grind/grindingwheel.htm

and IMO there is absolutely no comparison in terms of performance with the blue cutting very cool and clean.

I took a basic (Wickes) grinder and stripped off all the covers until I could install a 150/25mm wheel - note Peter will provide the necessary 20mm bore fittings with the wheel if asked. You can normally get a part used wheel at about half price which will work fine for hobby use. Stripping the safety covers means the shift goes over to my safety clothing and use but, bluntly, I believe any reliance on the supplied covers making these units inherently safe in normal use is very miss-guided.

Ah - I see Nev beat me too it by using less words!

 

[Robbo3]

I'll just add the same as the above.

As you have a 5" (125mm) grinder, you will find it hard to find a wheel other than the standard grey aluminium oxide. Also a 5" wheel puts a more concave (hollow) grind on the tools which can make them harder to use successfully. Note, I didn't say unusable, just harder to use.

A 6" or even an 8" grinder with white, pink (red) or even blue wheels is generally considered the norm for woodturning tools.

Lots of good information on the Peter Child woodturning site,
- http://www.peterchild.co.uk/grind/grindinfo.htm

Jumps - are you sure that the grinder shafts are 20mm? Most grinders are 1/2" (13mm).

Regards
Robbo

 

[jumps]

Jumps - are you sure that the grinder shafts are 20mm? Most grinders are 1/2" (13mm).

Regards
Robbo

Robbo,

I have absolutely no idea - I was taking the OPs information at face value

"...I know the size of the wheel, 125mmx13mmx20mm bore to fit on the Black and Decker ....."

He will be able to get whichever he needs - and if it's a bore of 13mm and a width of 20mm it will be a easier to get a wheel!

 

[Brian Littlewood]

Many thanks for the replies. It would appear that the wheel dimensions I'm after aren't easy to find. Yes, the bore does need to be 20mm and I was hoping for 125 dia and 13mm thick to attach easily to the old Black and Decker. I'd be very prepared to strip off the safety guides and use body protection as suggested. And, come the crunch, replace the grinder for one more appropriate to today's available wheel sizes. As to the choice between blue, white, red Peter Childs, Axminster etc, I've already done the rounds on these. So, back to the original question first please, can anyone suggest where I can find the wheel I described in the first place? If not, what would be the next best bet? I'm not opposed to buying a new grinder if that is what's needed.

Many thanks,

Brian

 

[cambournepete]

Phone Peter Child and ash them. They have sizes in stock not on their website.

As for removing the guards, if you're talking about the metal guards most of the way round the wheel then don't - if the wheel explodes you'll need them!

 

[KimG]

There is a video somewhere of an American woodworkers guild demo all about sharpening, a key point the demonstrator makes is that any wheel less than 150mm isn't really suitable for turning tool, the reason being that the hollow thus formed can be too deep and it prevents the bevel from rubbing properly, ideally you ought to perhaps think about a new grinder preferably with 200mm wheels if you do a lot of turning , otherwise go for a 150 at least.
If I find the video again I'll post it up.

 

[KimG]

OK, I found the video link, Click Here

 

[CHJ]

......As for removing the guards, if you're talking about the metal guards most of the way round the wheel then don't - if the wheel explodes you'll need them!

+1 for that advise, fortunately Grinding Wheels that have been handled correctly and not dropped or knocked before fitting correctly rarely shatter,* but if you have ever seen the damage that can be caused by one that has you would never ever think of going near one that's rotating at full speed without adequate containment guarding around it.

But if you are happy to stand around and let someone with a kilo+ hammer hit you in the face or chest and not bother about it then by all means have a go.

* Think very carefully before using second hand, partly used wheels with unknown handling or storage history, not likely to be problem if salvaged for use on a hand cranked bench grinder, but running at 2000+ rpm!!!.

 

[Brian Littlewood]

First of all thanks to everyone who responded to my last post. Especially to cambournepete and CHJ for their warnings not to work without guards. Fully understood and agreed! Thanks to cambournepete for suggesting a phone call to Peter Childs about getting the size right. And many thanks KimG for the comments and video link concerning the effects of too hollow a grind: I've been thinking for some time about how any concave grind must produce instability on a flat or cove cut; I decided it would be worth getting the oilstone out just to remove the curve at the cutting edge rather than to hone the tool. All your thoughts and suggestions have made a decision easy, that is to put the old Black and Decker workstation in the corner for use when I need to grind soft steel or use the chuck drive for the flapwheels etc. For grinding the lathe tools I'll upgrade to an 8" grinder using a wheel designed for use on HSS. As to precisely which grinder and which wheel, that will be the next decision but I've got a strong feeling it will be a lot more enjoyable than the last few weeks have been. And I'm sure it won't take anywhere nears as long! Once again, many thanks for your help.

All the best,

Brian

 

[nev]

Hi Brian
At the budget end of the grinder scale you could do a lot worse than a Record Power RPBG8 and it comes with a 40mm white wheel as standard.
cheers

 

[Brian Littlewood]

Thanks nev,

I've been looking at the RPBG6 for a while now as the best one to get. The only slight complication is the grey wheel on the right which would need replacing. I can't seem to find the bore so have asked Peter Childs for the measurement so that I can track down a wheel supplier, possibly Peter Childs themselves! You don't happen to have any thoughts do you?

All the best,

Brian

 

[CHJ]

Thanks nev,

I've been looking at the RPBG6 for a while now as the best one to get. The only slight complication is the grey wheel on the right which would need replacing. I can't seem to find the bore so have asked Peter Childs for the measurement so that I can track down a wheel supplier, possibly Peter Childs themselves! You don't happen to have any thoughts do you?

All the best,

Brian

This post may be of interest, I fitted a blue wheel from Peter Child in 2005 and it's still going strong.

A couple of observations,
It cuts very rapidly and freely so you need to use very light contact pressure else you will achieve two results very quickly.
1. Lots of tool steel removed,
2. Reduction of the wheel diameter, caused by the nature of the Blue wheel structure which is to all intents and purposes self sharpening by shedding micro crystal structures when they blunt.

 

[nev]

Thanks nev,

I've been looking at the RPBG6 for a while now as the best one to get. The only slight complication is the grey wheel on the right which would need replacing. I can't seem to find the bore so have asked Peter Childs for the measurement so that I can track down a wheel supplier, possibly Peter Childs themselves! You don't happen to have any thoughts do you?

All the best,

Brian

I have a rpbg6 because it was in my price bracket at the time and it has served me well.
Ian (Silverbirch ) has the same grinder with a pink wheel attached and I have put a pink or blue wheel from PC on my birthday list for the end of the month (fingers crossed ).
The white wheel will be more than adequate for your turning tools if funding is tight and a second finer wheel could be added at a later date. But if you're going to splash out you were to order the grinder and a wheel at the same time from the likes of Peter Childs , I wouldnt be surprised if they offered to fit it too.

 

[KimG]

Well the 8" has a 16mm shaft/bore, I would think it likely the 6" is the same.
You do need a slight hollow grind for turning tools though because if you didn't then the edge would never be supported by the bevel and it would dig in as soon as it touched the rotating wood, the shallow bevel you get with an 8" is ideal, and the grindstone will be good all the way down to 6 or even 5 inches, but you should replace it before that of course, the video link if you watch the whole series (I think there are 6) does cover this and it is an excellent demo, will give you a very good idea of what is required etc.

But this is the primary reason woodturners use wheels and NOT flatstones, the hollow grind is essential to proper working of the tool, just not too hollow as would result from a wheel 5 inches or less

 

[paulm]

I use a flat grind Kim, from my sorby pro-edge, after many years of using six inch wheels, and find it very predictable and easy to use on bowl, spindle gouges and skews etc.

Not sure about the idea that a hollow grind is necessary, or desirable..... ?

Cheers, Paul

 

[KimG]

Hi Paul, well you learn something new everyday, I have seen the Sorby Pro-edge of course, but it never occurred that it didn't give a hollow grind, obvious now of course!