Which vac for metalworking?

hdv

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I am planning to create a corner in my shop that is dedicated to metal working. For now it will just be a vice, a drill, a soldering station, and a belt sander.  Next up will be a metal saw and hopefully sometime in the coming months a small mill and/or lathe. I would really like to learn to weld. After that there'll probably a welding station too.

Now, on to the question. I plan on having dedicated extraction for all the metal stuff, because I really like the idea of not mixing hot metal with saw dust. However, I have no clue about good vacs for this. Do I buy a specialised vac? Or just a normal vac that will never be used for anything else? What do you guys do?
 
There are specialty manufacturers of vacuum systems for metal chips, however, they're usually very expensive.

My choice was to purchase a Milwaukee vac that has a stainless tub and can be used without a bag. The one I own is a Model 8925 which holds 15 gallons. There was also a smaller/shorter Milwaukee stainless unit that I think was 10 gallons and weighs a lot less.

Milwaukee also manufactured vacuums that had red painted steel tubs. I'd make you a bet you can find a used one for a song as they've been manufactured since the 70's.  [smile]  Parts are still available from Milwaukee if you find a rough one.

The ideal model would be one of the short ones so that you can pick it up and empty it into a garbage can.

These can also be used as wet vacs, the reason for the dump valve on the bottom of the photo, try searching for Milwaukee 8911, 8912, 8925, 8926 or 8950.

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I never see the point of dust extraction when working with metal. Metal dust doesn't get airborne, it drops straight to the ground. And if it's hot it is dangerous to suck into an enclosed space. When I work with metal I just let it drop to the ground and clean it up afterwards with a dust pan or a vac.
 
Alex said:
I never see the point of dust extraction when working with metal. Metal dust doesn't get airborne, it drops straight to the ground. And if it's hot it is dangerous to suck into an enclosed space. When I work with metal I just let it drop to the ground and clean it up afterwards with a dust pan or a vac.
As someone that does metal fabrication often I can say with certainty the airborne dust from grinding and plasma cutters goes everywhere and leaves a nice thick dark layer from ceiling to floor. It is considered a health hazard, along with smoke. There is not a good way to have dust collection on a common grinder, although the RAS does have a metal brush attachment. So I too cleanup after making a mess using a CT36...well kinda as the dust literally goes everywhere, and my cleanups are not that thorough. Cabinets with doors are one of the best solutions to keeping stuff clean.
 
hdv said:
I am planning to create a corner in my shop that is dedicated to metal working. For now it will just be a vice, a drill, a soldering station, and a belt sander.  Next up will be a metal saw and hopefully sometime in the coming months a small mill and/or lathe. I would really like to learn to weld. After that there'll probably a welding station too.

Now, on to the question. I plan on having dedicated extraction for all the metal stuff, because I really like the idea of not mixing hot metal with saw dust. However, I have no clue about good vacs for this. Do I buy a specialised vac? Or just a normal vac that will never be used for anything else? What do you guys do?

if you are just getting into metalworking, you might enjoy this. No discussion of vac choices but some guidance on what machine to buy next and some very good lessons on basic lathe and mill skills, layout, etc.
 
Cheese

That Milwaukee vac has the  cool factor going for it....looks like something from the 1950's.
 
Peter_C said:
As someone that does metal fabrication often I can say with certainty the airborne dust from grinding and plasma cutters goes everywhere and leaves a nice thick dark layer from ceiling to floor.

Grinded particles can't float in the air like wood dust and most other common dust types. Gravity will pull it to the ground immediately. Of course, if you have a lot of grinding going on, particles can be shot everywhere and stick to surfaces.

Plasma cutters can vaporise metal. That's something different.
 
Hi,welding curtains and exhaust fan work well plus broom or shop vac.guy
 
Rob Z said:
Cheese

That Milwaukee vac has the  cool factor going for it....looks like something from the 1950's.

Hey Rob...yes, I affectionately refer to it as R2D2... [big grin] I think the basic design was first produced in the 60's.
 
"Grinded particles can't float in the air like wood dust and most other common dust types."

Bull. I spent many a day grinding carbon and stainless steel and was covered with swarf by the end of the day. It gets in your ears and nose and mouth. This was decades ago (70s) before there was any concern about PPE. We were not issued earplugs for noise or dust masks. Hard hats, safety glasses, and a face shield was about the extent of the PPE we got. I worked in refineries and power plants for decades and I ate so much of that crud I think back on it and can't believe it. When you blow your nose it comes out black. Looks like coal dust. To say that stuff does not get airborne is wrong. It travels far enough to get in your lungs. Work like that in an enclosed space with 3 or 4 other guys grinding away and there is a cloud of that crud floating around, you can't help but breathe it in. Shake you jacket out and it rains silica dust and metal bits. It gets in your boots, your pockets, your wallet, and just about everywhere else.

Yes it will not 'float' for many yards but it does travel, mostly from the particles being thrown off of the grinder which are composed of bits of metal and the silica in the wheel as it is abraded away. I started most days with one 4-1/2 and one 7 inch grinder, a stack of a dozen 4-1/2" wheels, and one extra 7 inch wheel plus end grinder with some flap wheels and a file or two. By the end of the day most of those wheels were turned into dust. Maybe I would have one of each for the next day.
 
Bob D. said:
"Grinded particles can't float in the air like wood dust and most other common dust types."

Bull. I spent many a day grinding carbon and stainless steel and was covered with swarf by the end of the day. It gets in your ears and nose and mouth.

Go saw some wood in a room and you'll quickly find the air full of dust. Leave the room and come back an hour later, you'll still see the air itself is still full of wood dust.

Grind metal with a grinder and after a few seconds, all particles will have dropped down to the surface, and there will not a be any metal in the air anymore.

Bob D. said:
Yes it will not 'float' for many yards but it does travel, mostly from the particles being thrown off of the grinder which are composed of bits of metal and the silica in the wheel as it is abraded away.

Yup, this. Nobody here disputes you create a lot of dust when you grind metal. It is just too dense to float in the air. The grinding process itself is an energetic process so the particles are thrown away with force, and can reach up to the ceiling, even a high ceiling. But they still do not float in the air, gravity will pull them down as soon as they lose their momentum.

So back to the idea of needing a vac for metal work. Catching red hot metal particles is a dangerous thing as it can easily set your vac on fire. But if they simply fall to the ground on a solid non-flammable surface, like concrete, there's no fire danger at all.

Using a vac while sanding or sawing doesn't only keep the place clean, but is also a must for your health. Sawing and sanding without a vac will create a dust cloud you can breath in for hours and this is very bad. Grinding metal on the other hand, can create just as big a mess, but will not create a dust cloud that hangs in the air for hours and fill your lungs with metal.
 
Alex said:
Grind metal with a grinder and after a few seconds, all particles will have dropped down to the surface, and there will not a be any metal in the air anymore.
You have your experience and I have my observations as of last Saturday. My chair (Throne as my wife calls it) situated about 15ft (5 meters) away from where I was grinding and using a flap disk was covered in metal dust, to the point I cleaned it before sitting down. Going to grab some drywall shims off my highest cabinet which is white, I found it to be covered in a layer of black dust. I haven't used my plasma in a couple years as I just moved back into our house, so I have been rebuilding my welding cart again as the original wheels weren't rated for the 640#'s and failed in the rough moves. So the metal I grind does go full airborne. Maybe the flap disk creates more fine dust than a grinding disk, and I do tend to use flap disks a lot. I am not new to metal working as I started welding in 1983 fixing farming equipment. 

Fortunately Alex and I are most often in agreement on things :)
 
Actually Alex, the largest driving force for me, is to build a larger outside garage specifically so that i can move the metal working parts of my shop into the garage where hopefully the dirt and clutter will be less. I'm willing to declare that metal working is several times more toxic/dirty than wood working...hands down.

Wood working is dusty but metal working is horrible. A black layer of sediment covers every square inch of the shop and it's like fly paper...you just can't shake the stuff. The stuff is everywhere. It's in your nose, it's on your hands, it's on your face...I'd much rather deal with saw dust rather than metal grinding dust. Two days later and you're still trying to wash the stuff off of your hands. Your hands will literally turn black from the stuff and it will be several days before you can remove the metal dust from your person. The stuff is tragic.

 
Peter_C said:
So the metal I grind does go full airborne.

Shoot a gun, the bullet goes airborne, and quite far. Drop a bullet from your hand and it goes straight down. That's how it works with metal, from great to small.

Of course metal goes everywhere the moment you grind it. Grinding expells metal particles with great force.

Cheese said:
Wood working is dusty but metal working is horrible. A black layer of sediment covers every square inch of the shop and it's like fly paper...you just can't shake the stuff. The stuff is everywhere. It's in your nose, it's on your hands, it's on your face...I'd much rather deal with saw dust rather than metal grinding dust. Two days later and you're still trying to wash the stuff off of your hands. Your hands will literally turn black from the stuff and it will be several days before you can remove the metal dust from your person. The stuff is tragic.

Yeah, I know, Cheese metal dust is bad, sticks everywhere because it has sharp edges, and is also electrically charged which makes it even stickier.

But how is that going to be solved with a vac? How do you collect all the dust from a grinder? How do you make a hood for it that you can use in the many positions you hold a grinder? And how do you solve the red hot particles that can light your vac up?

Staying clean with metal working can be done, but it requires a strong cleaning discipline. When I worked in my father's body shop we had two metal working companies on the other side of the street we sprayed for on a regular basis. One dealt mostly with sheet goods making things like air ducts and containers for various types of equipment. That place was always squeeky clean. The last half our of the day the entire crew would clean the place up.

The other company dealt mostly with heavy metal, lots of H-beams, they built bridges, grain silos, structural supports for buildings, etc. When you walked in there it was like walking into the depths of Hades. Everything was covered in a dark layer of metal and grease, and the grinders and welders were spewing glowing metal everywhere, all day. At the end of the day, they drank a beer and went home.

I'm just a bit amazed the answer on this site always seems to be "more equipment" instead of more technique & more discipline.
 
I have a metalworking area in my shop with mill, lathe, belt sander, bench grinder, angle grinder. 
I am with Alex on this --- metal particles don't float in the air like sawdust.  But they do have a lot more velocity and momentum and I don't think you will be successful with point of use dust collection.  Maybe a little successful with grinder and belt sander.
For a drill press, mill, or lathe, the majority of the chip volume is too long and stringy to be collected effectively with a vacuum --- they are too likely to clog your vacuum hose.  I clean those up with brush and broom, and then use my CT-36 to clean up the left over smaller chips.
 
Alex said:
But how is that going to be solved with a vac? How do you collect all the dust from a grinder? How do you make a hood for it that you can use in the many positions you hold a grinder? And how do you solve the red hot particles that can light your vac up?

I'm just a bit amazed the answer on this site always seems to be "more equipment" instead of more technique & more discipline.

On the 8" Milwaukee bench grinder there is a 3 1/2" dust port on each wheel guard and on the 10" Milwaukee there is a 4 1/2" dust port on each wheel guard. Those were cast directly in the wheel guards by the original manufacturer Wissota. The same thing goes on Baldor bench grinders, they also have integral dust ports.

I also have a Jet combo machine with a 6" belt and a 12" disc, that also has a built-in 4" dust port on it. So a lot of the metal fab machinery is configured from the factory for dust collection and some of these items are over 20 years old.

Right angle grinders are a different issue, I just place the vac hose as close to the object as I can. The particles may be hot but they're pretty small and rapidly lose their heat inside the 10 foot hose before they fall into the stainless vac tub. When I move the metal operations to the garage, I'm going to fabricate a small hood just for use with the RA grinders.

And on your last point... [ban]  [smile]
 
Thanks for all the input!

I didn't ask because I was worried about health issues. I am and that's why I always wear a mask when I suspect that fine particles will hang in the air long enough or close enough for me to breathe them in. Irrespective whether wood, metal, or plastic. My lungs are bad enough as it is. I don't need to make it worse just for a hobby.  [crying]

However, in this case it was more about not having all that cruft everywhere in my shop. I like my shop to be tidy and clean. A bit like that role model ours here on the forum. He, Matt is that you...  [tongue]  (Sorry man, I just couldn't resist with all the FOGers getting on your case about that.  [cool])

[member=44099]Cheese[/member] : I really do like that Milwaukee with the metal bin. I might very try to find something like that.
 
It seems everyone agrees that metal dust does get airborne, even if it hangs around less than sawdust. I agree that there are no decent dust collection hoods for angle grinders, plus the hot chips are going to create a fire hazard if you're sucking them into a CT36. Cheese's Milwaukee vac looks like a good solution, though I'd probably investigate the ducting material used in the hose to make sure its abrasion and fire resistant. Good flex ducting able to handle abrasives and high temps are very expensive - see the GS HIGH TEMP product on this page at around $13 per foot for 2" diameter.

Like Cheese, I am religious about wearing PPE when grinding metal because I do think it's an order of magnitude more damaging than most sawdust, unless you're cutting exotics known for sensitizers. The Wood Database is a good way to look that up.

The only good solution I have found is wearing a 3M full-face respirator. I currently wear their model 6800 which offers a full face seal and is surprisingly comfortable. Also, it has the absolute best venting of any respirator I've ever worn, and has never fogged up on me, even when I'm outside in the heat. It's compatible with P100 disc filters which are fine for handling metal. If you do a lot of grinding, you can also use their 2297 P100 disc filters which offer the same particulate protection but also filter out "nuisance level" grinding dust fumes. This also acts as face/eye protection so the only thing I need to add is usually hearing protection.

Since there's no good way to collect grinding dust at the tool, the next best thing is to protect your lungs, leave, let it settle, and vacuum when you're done.
 
This is timely as my woodshop (shed) has morphed into a metal shop over the past year. 120SF is too small for either avocation, let alone both, but I find myself doing more metalwork lately. I havent found any efficient way to contain the mess yet, but I'm seriously interested.

I grew up the son of a carpenter, then did a ton of welding in my early 20's and now again pursue both hobbies. I was initially puzzled by YT'ers with their dedicated grinding rooms until I recently got back into metalwork deeply and recalled the grinding "dust" that is generated. On a tangent, my question is, why do we call the pursuit "welding" as shorthand when "grinding and sweeping up" takes up 5X the amount of time?

Anyway, metal grinding dust is insidious in a way that sawdust just isn't. For perhaps 5 minutes of actually gluing steel together last weekend:

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Angle grinders throw the dust everywhere and it doesn't clean up as neatly/completely as sawdust.

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Trust me [big grin]

RMW

 

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