Grinding dust

[Paul Durden]

Should have posted here rather than getting started from…my bad

Tool Grinding dust. Is this still a real health concern if I just wear a n90 mask when grinding/sharpening lathe tools? Black dust still gets all over the workbench and nearby. I’m using a Sorby ProEdge. (linisher -belt sander type sharpener)

 

[Russell Nugent]

Should have posted here rather than getting started from…my bad

Tool Grinding dust. Is this still a real health concern if I just wear a n90 mask when grinding/sharpening lathe tools? Black dust still gets all over the workbench and nearby. I’m using a Sorby ProEdge. (linisher -belt sander type sharpener)

I hook magnets all around my grinder, picks up a lot of dust but still get lots of dust all over. If you're grinding a tool wearing a mask great. If you shut off the grinder and then take off the mask, realistically you're breathing in the finer metal particles. I generally sharpen while I'm turning so still wearing my Airshield pro.

 

[hughie]

I hook magnets all around my grinder, picks up a lot of dust but still get lots of dust all over. If you're grinding a tool wearing a mask great. If you shut off the grinder and then take off the mask, realistically you're breathing in the finer metal particles. I generally sharpen while I'm turning so still wearing my Airshield pro.

Same here i use rare earth magnets and it amazing how much they collect. With carbide, the dust is super toxic, so face mask and move grinder close to the door and fan blow it all outside.

 

[John K Jordan]

Should have posted here rather than getting started from…my bad

Tool Grinding dust. Is this still a real health concern if I just wear a n90 mask when grinding/sharpening lathe tools? Black dust still gets all over the workbench and nearby. I’m using a Sorby ProEdge. (linisher -belt sander type sharpener)

I hook magnets all around my grinder, picks up a lot of dust but still get lots of dust all over. If you're grinding a tool wearing a mask great. If you shut off the grinder and then take off the mask, realistically you're breathing in the finer metal particles....

I'm not familiar with the ProEdge but if the dust is black and the belt isn't, it's prob fine steel. I get a lot from CBN wheels and with a strong light and a dark background I can see it floating the air around the room. I even found fine black dust on magnets stuck on the backside of my bandsaw cabinet, the side away from the grinder, over 10' away - proof the dust floats well, maybe like pollen, and probably all around the room. I am primarily using 600grit CBN so maybe the dust from mine is finer than some.

Last time I checked I still wasn't a pulmonary doctor or researcher but my guess is it might not be beneficial for the lungs. (Unless maybe it rusted quickly and the iron entered the bloodstream and enriched the blood! Somebody quick, do a study...)

I like the 3M half-mask industrial respirators, also available from Home Depot (or used to be). The 7000 series are softer and more comfortable. Price was $10 cheaper for the last one I got, a year ago - oh well.)

Amazon.com

I use the pink P100 particle filters which are better than the N95 masks, and the respirator fits and seals far better than a typical mask. But I suspect the dust mask would be better than nothing.

One huge FIRE caution about magnets: my experience: A lot of people use magnets near or below their grinders. Some put them in plastic bags to make them easier to clean off the black steel particles. I mounted a strong super magnet just below a CBN wheel and it immediately started picking up black dust and eventually accumulated enough to make a fuzzy ball around the magnet. We all know, if watching closely, a CBN does throw an occasional tiny spark. Well, one of those tiny sparks must have found it's way just right (or wrong) into the fuzzy ball of steel dust. I happened to look down and saw an orange glow deep inside the fuzz. Any kid who's ever played with taking a match or torch to fine steel wool knows how well it burns.

The steel dust on the magnet had ignited and was forming a ball of molten steel inside. I scooped up the magnet and took it outside.

I still use the magnet but keep it cleaned off better. The grinder was on a stainless steel table but I have it and a Oneway Wolverine mounted to a piece of plywood on top the table. Hate to burn the shop down by sharpening lathe tools!

JKJ

 

[Marty Vogel]

I had the dust on my magnets under my grinder catch fire also the other day.
I assumed it was the plastic bag catching on fire............

 

[Jon Rista]

Using a magent is pretty smart. I am curious, though...has anyone ever tried to set up or rig up a way to hold a dust capture or shop vac inlet somewhere near the wheel? Not sure the best place to put an inlet, but, on top of magnets, I wonder if that mgiht help?

I generally wear PPE, but sometimes I have ground without, and noticed that metallic taste in the air. I actually wonder if maybe its more than just getting an intake near the wheel...maybe the wheel should be kind of wrapped in an intake so it captures grinding dust from the whole area...

 

[Tom Gall]

Using a magent is pretty smart. I am curious, though...has anyone ever tried to set up or rig up a way to hold a dust capture or shop vac inlet somewhere near the wheel? Not sure the best place to put an inlet, but, on top of magnets, I wonder if that mgiht help?

I generally wear PPE, but sometimes I have ground without, and noticed that metallic taste in the air. I actually wonder if maybe its more than just getting an intake near the wheel...maybe the wheel should be kind of wrapped in an intake so it captures grinding dust from the whole area...

There have been several discussions about this in previous years (2020-2022). Here is a link to my latest response. Magnetic Dust Chute

 

[Aaron Harris]

I'm not familiar with the ProEdge but if the dust is black and the belt isn't, it's prob fine steel. I get a lot from CBN wheels and with a strong light and a dark background I can see it floating the air around the room. I even found fine black dust on magnets stuck on the backside of my bandsaw cabinet, the side away from the grinder, over 10' away - proof the dust floats well, maybe like pollen, and probably all around the room. I am primarily using 600grit CBN so maybe the dust from mine is finer than some.

Last time I checked I still wasn't a pulmonary doctor or researcher but my guess is it might not be beneficial for the lungs. (Unless maybe it rusted quickly and the iron entered the bloodstream and enriched the blood! Somebody quick, do a study...)

I like the 3M half-mask industrial respirators, also available from Home Depot (or used to be). The 7000 series are softer and more comfortable. Price was $10 cheaper for the last one I got, a year ago - oh well.)

Amazon.com

I use the pink P100 particle filters which are better than the N95 masks, and the respirator fits and seals far better than a typical mask. But I suspect the dust mask would be better than nothing.

One huge FIRE caution about magnets: my experience: A lot of people use magnets near or below their grinders. Some put them in plastic bags to make them easier to clean off the black steel particles. I mounted a strong super magnet just below a CBN wheel and it immediately started picking up black dust and eventually accumulated enough to make a fuzzy ball around the magnet. We all know, if watching closely, a CBN does throw an occasional tiny spark. Well, one of those tiny sparks must have found it's way just right (or wrong) into the fuzzy ball of steel dust. I happened to look down and saw an orange glow deep inside the fuzz. Any kid who's ever played with taking a match or torch to fine steel wool knows how well it burns.

The steel dust on the magnet had ignited and was forming a ball of molten steel inside. I scooped up the magnet and took it outside.

I still use the magnet but keep it cleaned off better. The grinder was on a stainless steel table but I have it and a Oneway Wolverine mounted to a piece of plywood on top the table. Hate to burn the shop down by sharpening lathe tools!

JKJ

John-I had this same experience not long ago when doing a lot of grinding on my 80-grit CBN with the magnet inside the sandwich bag. I started smelling burning plastic and metal, looked down and saw the red eye of Sauron glowing and about to ignite in the metal-dust. I just reached for my spray bottle of water on the same bench, and soaked it good. Ever since then, I have taken to spraying both the wheel and the tool about to be sharpened with water trying to tame both the heat and the dust. It seems to help, and has no effect on the wheel or my tools. I also keep used (not oily) shop rags in a box under the bench. When I'm ready to clean up around the grinder, I spray a couple of rags to give a good wipe-down to get most of it before vacuming and blowing off with compressed air. Trying to wet the dust while it is being produced and later when it is cleaned up can't hurt, I figure, and also might keep me from burning my shop down!

 

[John Whitley]

Using a magent is pretty smart. I am curious, though...has anyone ever tried to set up or rig up a way to hold a dust capture or shop vac inlet somewhere near the wheel? Not sure the best place to put an inlet, but, on top of magnets, I wonder if that mgiht help?

I generally wear PPE, but sometimes I have ground without, and noticed that metallic taste in the air. I actually wonder if maybe its more than just getting an intake near the wheel...maybe the wheel should be kind of wrapped in an intake so it captures grinding dust from the whole area...

(tl;dr: I don’t think ANY current metal dust collection approach actually works well enough to forgo robust breathing protection such as a good half-mask or PAPR. And I don’t believe anyone who says otherwise who hasn’t actually done before/after measurements. A dirty magnet says nothing about the metal dust that got away.)

I actually have a JET Metal Dust Collector (JDCS-505). It’s a metal dust collector base designed for bench grinders. It helps, but I’m not blown away by it(**). IMO, it’s only OK because I’m already wearing a PAPR and because I have a big exhaust fan mounted in the back wall of the shop – I can quickly clear out any dust that the big dust collector doesn’t catch. One key problem is that bench grinder wheel guards are designed to catch debris from an exploding friable wheel first and …. somewhere much later down the list …. actually allow dust collection. The problem is particularly acute when platform grinding (hi skew, 40/40 grinds), as a properly close-set platform acts as an amazing diverter of grinding dust. A significant amount of dust hits the platform and never gets anywhere near the wheel shroud and collection zone.

Nor are magnets magic; they fail in a similar way to fan-driven dust collectors in that magnetic pull force or suction force drops off extremely rapidly with distance (an inverse cube law, iirc). (See charts here, for example.) Likewise, I’ve yet to see anyone using a magnetic dust collection approach actually take measurements (e.g. with a Dylos or other reliable air quality meter/particle counter) and do a before/after test. Sure, a nice neodymium magnet will catch dust that happens to wander close by it… but just like with a fan-driven dust collector, if the dust escapes the capture zone it’s now just part of the shop atmosphere.

I have a project, maybe more of a lark, in mind to design a custom wheel shroud that tries to significantly improve dust routing and capture. The rationale is that the guards on my grinder are so obviously bad at dust collection, and clearly hinder what my collector might otherwise achieve. I suspect that this is a necessary first step, but even that may not be sufficient.

(**) Because I’ve measured the results using my Dylos air quality monitor.

 

[Jon Rista]

(tl;dr: I don’t think ANY current metal dust collection approach actually works well enough to forgo robust breathing protection such as a good half-mask or PAPR. And I don’t believe anyone who says otherwise who hasn’t actually done before/after measurements. A dirty magnet says nothing about the metal dust that got away.)

I actually have a JET Metal Dust Collector (JDCS-505). It’s a metal dust collector base designed for bench grinders. It helps, but I’m not blown away by it(**). IMO, it’s only OK because I’m already wearing a PAPR and because I have a big exhaust fan mounted in the back wall of the shop – I can quickly clear out any dust that the big dust collector doesn’t catch. One key problem is that bench grinder wheel guards are designed to catch debris from an exploding friable wheel first and …. somewhere much later down the list …. actually allow dust collection. The problem is particularly acute when platform grinding (hi skew, 40/40 grinds), as a properly close-set platform acts as an amazing diverter of grinding dust. A significant amount of dust hits the platform and never gets anywhere near the wheel shroud and collection zone.

Nor are magnets magic; they fail in a similar way to fan-driven dust collectors in that magnetic pull force or suction force drops off extremely rapidly with distance (an inverse cube law, iirc). (See charts here, for example.) Likewise, I’ve yet to see anyone using a magnetic dust collection approach actually take measurements (e.g. with a Dylos or other reliable air quality meter/particle counter) and do a before/after test. Sure, a nice neodymium magnet will catch dust that happens to wander close by it… but just like with a fan-driven dust collector, if the dust escapes the capture zone it’s now just part of the shop atmosphere.

I have a project, maybe more of a lark, in mind to design a custom wheel shroud that tries to significantly improve dust routing and capture. The rationale is that the guards on my grinder are so obviously bad at dust collection, and clearly hinder what my collector might otherwise achieve. I suspect that this is a necessary first step, but even that may not be sufficient.

(**) Because I’ve measured the results using my Dylos air quality monitor.

Wholly agree about still using PPE. I was more concerned about the metal buildup on the bench and everything. I also have a long power bar behind that workbench (which is where I've attached many of my benchtop power tools, including the grinder.) I plug all the outlets with outlet caps, to make sure no metal filings get in there. But it builds up quite a lot, and I'd like more active cleanup of it.

 

[John K Jordan]

also might keep me from burning my shop down!

I HATE to hear of a shop that burned down. I know someone who lost his shop, all the wood, and all the tools because a pressure cut-off switch on a big air compressor failed. He wasn't at home at the time. The motor overheated and the rest of the story is ash. Almost another horrible thing - when visiting him once we walked from the house to the (new) shop and the (new) air compressor was running. That switch had failed. What are the CHANCES?

After learning about the first fire I built my shop with the master switch to the 5hp compressor motor on the wall OUTSIDE the sound insulated closet so I can see it from the door when I leave the shop.

When I was a kid I played with a lot of iron and aluminum dust, would light magnesium shavings (burn oh, so well) and mix all kinds of combustible and explosive things, was a real pyro, all non=destructive. Somehow I lived to tell about it. Iron powder, especially rusty, mixed with aluminum powder when ignited can make thermite - gets hot enough to weld steel. Once in the high school chemistry lab a guy mixed up some mercury fulminate and with poor judgement put the wet goop on a paper towel on the windowsill of an open window to dry. When it dried, someone opened a door, the paper blew out the window. It ignights with a shock, left a burned streak down the brick from the second story window that was there for a couple of years. Ask me sometime about the flying saucer explosion and the jet backpack. Somehow we all lived through it. Lots of things in the 60s that were just "kids playing but would bring authorities these days. I mostly hung out with wizards who liked good clean fun, mostly with fire, electronics, mechanical contraptions, and high voltage. Science fair time was the highlight of the year. My mother later sent me a newspaper article later about some of the area chemistry geeks (who I didn't know) who decided to make some money designing and selling drugs. That didn't go over well with the authorities.

Just the plain extremely fine iron (or HSS) powder can be ignighted with the tiniest spark from a CBN wheel., won't easily burst into flame, but create a blob of molten steel in the middle that can get larger and drop onto the table and maybe bounce on the floor. Could cause serious flesh burns or worse. A science/engineering wizard frind has me save all the dust from the CBN wheels for him to play with. I keep them in a glass jar.

JKJ