Grinding Wheel Safety - Saw Chain Sharpening

[Philbert]

Most people are pretty casual with grinding wheels, especially the smaller ones used on common chainsaw grinders. But, if you have ever had one explode, you start to pay a little more attention to all of that safety 'stuff' about guards, and ring tests, and wearing safety glasses, etc.

I have had wheels on small chainsaw grinders go flying across the room, and I have had guys in large machine shops point out dents in ceiling joists 30 feet above. The operative word is 'explode'.

So I was surprised, recently, to receive some name brand grinding wheels without the paper 'blotters' on one side, and some cheap grinding wheels without any. Many people think of these only as labels. But the purpose of the blotter is actually to cushion and distribute the clamping force from the metal flanges evenly across the brittle, vitrified wheel surface, eliminating concentrated pressure points.

(Vitrified Grinding Wheel - the paper labels are called 'blotters')

I called Molemab, and spoke to a technical representative, to make sure that I was not misunderstanding the need for blotters. He confirmed that the vitrified wheels, in this application, do require them. But that resinoid wheels may not need them, due to their construction.


(Resinoid Wheel - no blotters)

I could act shocked that the wheels on some of the 'HF-type' grinders don't have any blotters. I asked if maybe these fall into some type of exception, but the rep did not think so.

Anyway, if you get some grinding wheels without the blotters, check with your vendor about replacements (or blotters). They don't explode often, but when the do, it gets really exciting . . . .

Philbert

http://www.nortonindustrial.com/uploadedFiles/SGindnortonabrasives/Documents/Safety - Blotters - What Good Are They.pdf

http://www.nortonindustrial.com/upl...Safety-BlotterSizeVersusFlangeSize-Norton.pdf

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9839

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10691

 

[c5rulz]

Morning Philbert


Another thing people can do is to stand to the side when starting the grinder. If it's going to let go, chances are it will be on start up right after changing a wheel.

 

[farmerward]

Most people are pretty casual with grinding wheels, especially the smaller ones used on common chainsaw grinders. But, if you have ever had one explode, you start to pay a little more attention to all of that safety 'stuff' about guards, and ring tests, and wearing safety glasses, etc.

I have had wheels on small chainsaw grinders go flying across the room, and I have had guys in large machine shops point out dents in ceiling joists 30 feet above. The operative word is 'explode'.

So I was surprised, recently, to receive some name brand grinding wheels without the paper 'blotters' on one side, and some cheap grinding wheels without any. Many people think of these only as labels. But the purpose of the blotter is actually to cushion and distribute the clamping force from the metal flanges evenly across the brittle, vitrified wheel surface, eliminating concentrated pressure points.
View attachment 451148
(Vitrified Grinding Wheel - the paper labels are called 'blotters')

I called Molemab, and spoke to a technical representative, to make sure that I was not misunderstanding the need for blotters. He confirmed that the vitrified wheels, in this application, do require them. But that resinoid wheels may not need them, due to their construction.

View attachment 451149
(Resinoid Wheel - no blotters)

I could act shocked that the wheels on some of the 'HF-type' grinders don't have any blotters. I asked if maybe these fall into some type of exception, but the rep did not think so.

Anyway, if you get some grinding wheels without the blotters, check with your vendor about replacements (or blotters). They don't explode often, but when the do, it gets really exciting . . . .

Philbert

http://www.nortonindustrial.com/uploadedFiles/SGindnortonabrasives/Documents/Safety - Blotters - What Good Are They.pdf

http://www.nortonindustrial.com/upl...Safety-BlotterSizeVersusFlangeSize-Norton.pdf

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9839

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10691

Oops! I took the blotter off as soon as I got my new sharpener because I thought it had no purpose, oh well


Sent from my iPad using Tapatalk

 

[strtspdlx]

I never knew that... All mine I take off. Guess I won't be from now on. Explains why they don't feel like normal paper.


Regards-Carlo

 

[HarleyT]

Also, they cushion the wheel as the hub bolt tightens up, taking up for any unevenness too, so you don't send hairline cracks throughout the wheel when it gets tight.

 

[Bill Becker]

I gave away all my electric bench mount grinders, hand held grinders and filing jigs, rigs and gadgets after I tried this:

These are on all my trucks and all my guys know how to use them.

 

[Nitroman]

Morning Philbert


Another thing people can do is to stand to the side when starting the grinder. If it's going to let go, chances are it will be on start up right after changing a wheel.

And don't dwadle around in the same plane as the wheel, it is like gambling.

 

[lambs]

We should do a poll on how many wheels have exploded on you; say zero through 5+. Might be interesting.

I guess another advantage of a steel based wheel.

 

[Philbert]

I have also had a few that flunked the 'ring test' - one of those things I do because I am 'supposed' to. Surprise when you get the 'dull' sound, but don't see any obvious cracks.

Philbert

 

[ChoppyChoppy]

We should do a poll on how many wheels have exploded on you; say zero through 5+. Might be interesting.

I guess another advantage of a steel based wheel.

I'm not sure how many chains we've sharpened at the shop, tens of thousands I'd guess.. enough to completely wear out 2 Oregon 510 grinders and the current "main" one is pretty well shot too.
Anyhow, no issues here with wheels. Well, aside from a few wheels that vibrated worse than a "ladytoy" right out of the box, brand new.

Not to say that I don't completely believe that grinder wheels can come apart. I think what helps on the chain grinders is the fairly slow rpms and fairly light wheels. The Oregon grinders are around 3200 rpms I believe? Much lower than an angle grinder or air powered grinder.
Or a bench grinder, horizontal grinder, etc that uses wheels that may weigh a few pounds.

 

[Philbert]

Saw these today at a local Lowe's. Pre-cracked. No blotters.



Philbert

 

[MarcS]

Good advise Phil. I've had a 20"x3" wheel explode on a large surface grinder before...grinding wheels are dangerous if mishandled. Blotters and ring tests are absolutely crucial.

 

[singletrack100]

Thank you guys! I don't have a chain grinder, do it all by hand. But I do a lot of shop work and never heard of the ring test. I googled it- I spent a lot of time in the auto and metal shop in school in the day and don't remember it either! Thank you for that' I'll certainly put that to use as I need to change bench grinder wheels soon!

Duane

 

[Philbert]

BUMP
(this came up in another conversation).


Philbert