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Inhaling metal dust particles...

R

robo hippy

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Well, I made an interesting discovery today. I took a Moffat lamp down from a shelf that was about 30 inches above my grinder. I have CBN wheels on my grinder. It was still in the closed box. When I opened it up (1/4 round dog ears that tuck into the sides, but not taped), there was a ring of fine metal dust particles on the box that had the magnetic base inside it. I never thought that the metal dust was fine enough, and thought it was too heavy to float around like that. I asked if it was any kind of health risk. Ralph Lindberg said that when he was in the Navy, full respiratory protection was required for any metal grinding or chipping.

Some thing to ponder...

robo hippy
 
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I have placed several rare earth ( hard drive ) magnets around the bottom of the CBN wheels.
The coarse wheel side collects more, makes sense.
Right now the wheels are unguarded, but I think that I will make some sort of housing for them.
 
robo hippy said:
Well, I made an interesting discovery today. I took a Moffat lamp down from a shelf that was about 30 inches above my grinder. I have CBN wheels on my grinder. It was still in the closed box. When I opened it up (1/4 round dog ears that tuck into the sides, but not taped), there was a ring of fine metal dust particles on the box that had the magnetic base inside it. I never thought that the metal dust was fine enough, and thought it was too heavy to float around like that. I asked if it was any kind of health risk. Ralph Lindberg said that when he was in the Navy, full respiratory protection was required for any metal grinding or chipping.

Some thing to ponder...

robo hippy
Click to expand...

Taking your suggestion and doing some pondering, it seems there really isn't a reason to expect a minimum size on the metal particles -- and super fine metallic dust can hang around the air for quite a long time -- just like smog does.
 
Bill Boehme said:
Taking your suggestion and doing some pondering, it seems there really isn't a reason to expect a minimum size on the metal particles -- and super fine metallic dust can hang around the air for quite a long time -- just like smog does.
Click to expand...

I have my CBN wheel sort of in the housing of the Rikon grinder. The side is off because the wheel is too wide. I put some magnets on the bottom of the housing (rare earth) and haven't seen any real result. I thought that, as the wheel spun it would fling the particles and the magnet would grab them but doesn't seem to be doing much if anything. The drawing shows what I'm referring to.

Perhaps a vacuum hooked up to the grinder would be prudent? Not looking forward to the noise but better that than sucking up steel bits. I quit smoking 25 years ago for a reason (see my signature) 😀

grinder.jpg
 
If I understand correctly, you put the magnets on the outside of the shroud. If that is the case and assuming that the shroud is steel, it's no wonder that they aren't working. Magnetic shield.

You could put them on the inside of the shroud and have a little better results, but personally I have a strange aversion to magnetizing things that are in the vicinity of metallic dust -- just seems like an all around bad thing to be doing. The air velocity inside the shroud also may be high enough to reduce the effectiveness of the magnet anyway. I think that a shop vac plumbed into your shroud might be more effective. Some people do not have shrouds around their wheels and use magnets a bit further away. I have no idea how much of the metallic dust they catch, but it certainly is better than nothing.
 
Bill Boehme said:
If I understand correctly, you put the magnets on the outside of the shroud. If that is the case and assuming that the shroud is steel, it's no wonder that they aren't working. Magnetic shield.

You could put them on the inside of the shroud and have a little better results, but personally I have a strange aversion to magnetizing things that are in the vicinity of metallic dust -- just seems like an all around bad thing to be doing. The air velocity inside the shroud also may be high enough to reduce the effectiveness of the magnet anyway. I think that a shop vac plumbed into your shroud might be more effective. Some people do not have shrouds around their wheels and use magnets a bit further away. I have no idea how much of the metallic dust they catch, but it certainly is better than nothing.
Click to expand...

I could put the magnets farther away (on the inside). My reasoning was that this was the lowest point. But the vac is probably the way I'm going to go. A bucket vac from lowes runs $20 so it's a cheap experiment.

I think you're right about the air velocity in the shroud. The vac will pull from the side. Gotta come up with a makeshift cover. And also a filter of some sort on the exhaust. Something to keep the fine stuff from just blowing out the vacuum discharge.
 
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Any sanding or grinding would require some sort of dust mask or respirator. A DC system would make it even better.
 
John Torchick said:
Any sanding or grinding would require some sort of dust mask or respirator. A DC system would make it even better.
Click to expand...

John,

I hadn't thought of that but a respirator is a good idea. Up until recently I've been using a Jet wet grinder. The CBN is very new to me. I can use a respirator during the process but still need to collect the suspended particles that are left long after. I thought about my DC but I'm wondering if a high velocity vacuum might not be better for this purpose? I have an extra one of those auto switches that kick on an auxiliary so when the grinder powers up it would come on. I also have the whole grinder setup on a tool cart with an enclosed cabinet. I was thinking about housing the vacuum in the cabinet (after opening up a spot for airflow and putting a small filter in it).

Any thoughts on this approach?

Thanks,

Mark
 
I have a CBN wheel that fortunately I use only for shaping and therefore rarely. I warned of metal dust in a previous post. I still believe that, like the old timers, wet grinding is the best for safety and results, mainly considering that while in the high carbon steel manganese may be the only toxic molecule, in high speed steel and powder steels there are mane very toxic metals.
 
Sergio Villa said:
I have a CBN wheel that fortunately I use only for shaping and therefore rarely. I warned of metal dust in a previous post. I still believe that, like the old timers, wet grinding is the best for safety and results, mainly considering that while in the high carbon steel manganese may be the only toxic molecule, in high speed steel and powder steels there are mane very toxic metals.
Click to expand...

Sergio,

I recently got that CBN wheel and became so enamored of it that I started using it almost exclusively. And the truth is that the Jet does a very nice job. I just hated the mess. Perhaps I'd save my lungs - and some of the tool longevity - by using the Jet more and the CBN a little less. 🙂

Still want to collect the particulate matter though for when I am using either the CBN or the AO wheels on the Rikon.

Mark
 
Sometimes, the best solutions are the easy reapplication of known methods. I didn't think this up; it's been used in different ways for many years.
 
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