Planning a New Shop – Dust Collection Ideas for Grinding Room?

M

Marko Veselinovic

Joined
Aug 3, 2020
Messages
32
Hi everyone,

I’m in the early stages of planning a new shop focused mainly on knife making. Nothing has been built yet — I’m trying to think everything through carefully before starting. My property is a bit limited in size and layout, but I should be able to fit a decent workspace.

Here’s the basic plan so far:

The shop will be divided into two main areas:
  • A larger general workspace
  • A smaller, enclosed grinding room
I have a similar setup in my current shop, and having a dedicated grinding room has honestly been one of the best decisions I made. In the new build, I want to expand it to fit:
  • Multiple belt and disc grinders
  • A surface grinder with a belt conversion
  • A vise for occasional angle grinder work
  • Buffers
(The precision surface grinder with a traditional wheel and flood coolant will stay in the general area for when I need really fine, micron-level removal.)

There will also be a small office space and a large open (just roofed) area at the front of the workshop, connected via a big roller door.


Now here’s where I need advice:

I’m thinking of adding a small attached room or shed right next to the grinding room to house my big compressor and the dust collection system.

My goal is to have one large dust collector with ducting run to all the machines in the grinding room. I’ve seen setups like this in woodworking shops — but of course, they’re not dealing with metal sparks and abrasive dust.

The separate room should help with noise, and if some fine dust escapes, it’s contained. I even considered just venting a turbine outside, but that doesn’t seem like a responsible solution — even though local regulations where I live aren’t that strict.


Has anyone here built something similar or have experience with metal dust collection systems?

Would really appreciate any input or photos of your setups if you’ve tackled this problem before. Thanks!
 
As strong as box store magnets have gotten, I've often wondered whether there couldn't be a magnetic dust collection system invented. As simple as a shield with some magnets stuck to the back. I have three nickel-sized magnets that I had in my pocket while grinding the other day and I looked down and thought I had ripped my shorts or that it had grown a beard. If had about a cubic inch of metal dust stuck to the outside of my shorts. They're almost impossible to clean because wiping them just moves the metal dust around the surface and I have to get tweezers to pick them clean (or stack two of the three and run them across one with a piece of cotton or paper in between). Even my iphone can't stay in my pocket while grinding because of its magnets.
 
Last edited:
The magnet thing is flawed, sparks are hot, and when steel gets hot it loses magnetic properties (Curie temperature). Plus they don`t do anything for dust when grinding handles, buffing etc.
 
Marko Veselinovic said:
The magnet thing is flawed, sparks are hot, and when steel gets hot it loses magnetic properties (Curie temperature). Plus they don`t do anything for dust when grinding handles, buffing etc.
Click to expand...
Well, that shows my verified newbie status! Are the grinders getting steel so hot that they turn non-magnetic? I didn't think so. And the magnet in my pocket didn't know any better. And yes, they won't collect non-ferrous particles. I was thinking about a supplement to a vacuum system.
 
Well if something is a spark, it is very hot indeed, hot enough to glow :) . Now when it cools down it will be magnetic again. But a better thing then magnets is just to have a water bucket underneath you grinder.
 
Marko Veselinovic said:
Well if something is a spark, it is very hot indeed, hot enough to glow :) . Now when it cools down it will be magnetic again. But a better thing then magnets is just to have a water bucket underneath you grinder.
Click to expand...
For sure. I didn't think that the sparks were non-magnetic hot, but what the heck do I know!! I'm new to all of this and have been thinking of ways to stop from having to shop vac my bench so often!
 
JustinGreen said:
As strong as box store magnets have gotten, I've often wondered whether there couldn't be a magnetic dust collection system invented. As simple as a shield with some magnets stuck to the back. I have three nickel-sized magnets that I had in my pocket while grinding the other day and I looked down and thought I had ripped my shorts or that it had grown a beard. If had about a cubic inch of metal dust stuck to the outside of my shorts. They're almost impossible to clean because wiping them just moves the metal dust around the surface and I have to get tweezers to pick them clean (or .s tack two of the three and run them across one with a piece of cotton or paper in between). Even my iphone can't stay in my pocket while grinding because of its magnets.
Click to expand...
I have done this for years. I have cheap HF welding magnets sitting all over the bench in the path of the debris. It catches lots of steel fragments Only the dust and some fine stuff go into the vac. Problem is that the magnetized metal shards are pretty much like steel wool. One tiny spark from the showers of sparks will light it . At the end of a grinding session, I put on a cotton glove and wipe the filings off te magnets as much as I can, clean the bench up well, and dunk all the magnets in the dunk tank just to be safe ... if you don't your bench will end up on fire. I have some serious charcoal areas where it burned into the wood from long grinding days.
It would be far better to make a dedicated water trap grinding vacuum setup. There are dozens of threads on building them.

Putting the equipment in a weather tight shed is a very wise idea. It keeps the noise out of the shop and makes maintenance easier. A Rubber Maid or Costco shed works well if you don't ant to build one.

Other ideas are:
Make the walls to the grinding room four foot high half walls, and put windows from there to the ceiling. It allows light and you can see out as well as guests can see in. Use a glass storm door for the same reason

Make sure the grinding room is sealed from the main shop. Dust will get out if not pretty well sealed. It doesn't need to be air tight, but there should not be big openings and gaps.

Have an Air-In and/Air-Out setup to bring fresh air in the shop. The vac system will make serious negative air pressure. Air in should be 50% more area than air out.

Put twice the lighting you think you need in te grinding room. It will still be less than you need. You want 5000-6000K spectrum.

A hanging air cleaner is also a great thing. Most will run for about 30 minutes after shutting them off for the day to clean the air to HIPA standards. Clean the filters weekly. They catch a lot of dust that would end up in your lungs. Look at the ones from Woodcraft or HF. This is money well spent.

If possible, have the dust catch system and vacuum motor in the shed or other room. Space in the grinding room is precious.

Cover the counter tops with metal. thin sheet aluminum will work fine. Mine are 20-gauge stainless ... but the 10X4' sheets were free.

Store EVERYTHING in the grinding room in clear bins with tight lids. Put them under the bench when possible. Again, bench top space is precious real estate in the grinding room. Shelving above the bench should be wire closet shelving, as dust will just fall through it. Put supplies on these shelves in smaller clear bins with tight lids.

Vacuum the benchtop regular .. even daily. Clean work areas are safer as well as prettier. Vacuuming the equipment often extends its life, too.

Put all accessories in closed bins or hang on the walls over the bench. The only stuff sitting on the bench should be knives. Small tools and grinder things can be in a shoebox size storage bin.

As notedin the above suggestions, dust is the enemy of a nice grinding room. If there is an open box or bin, it will slowly fill with dust. If there is a quiet corner or nook behind a machine ... it will fill with dust.
 
Stacy E. Apelt - Bladesmith said:
Make sure the grinding room is sealed from the main shop
Click to expand...
The grinding room as the rest of the shop will be fully insulated and closed up space. Also it will be climate controlled.
It will have as much windows as my property allows me to put. And the lighting I cant agree more with, there is no thing as too much lighting in a grinding room :).
There will be no benches, as I don't like that in the grinding room, every machine will have its own stand, and appropriate storage for accessories.
I also plan to add a very powerful fan close to the sealing and a place close to the floor that air can enter (preferably on the opposite side), so that i can "flush" the air out of the grinding room very quickly. This will be somewhat of an issue, I will lose heat in the winter, and cold air in the summer. I think that will be a negative, but something you can live with. This in my opinion is a better option then to circle the air inside through a filter, but I might add that to...

The main thing is that I would like to collect as much of the dust at its source, that's why the dust collector is something I want to do right.
 
If I ever get to build a shop the way I’d like I’ll have a concrete pad with an awning on the side with the grinding room and one 2x72 on a rolling stand I can roll outside for hogging and the real dusty stuff. I live in Alabama so it gets a little hot in the summer but I’d be able to grind outside pretty much year round.

It will also have windows and/doors on every wall so I can get good airflow through it. Outside of that my other main objective will be to have enough lighting in it I’ll have to wear sunscreen inside.
 
There's some good advice in this thread and also a bunch of other threads linked in one of the posts.
J. Keeton

Thread 'RBO Grinding Room Build (12'x6.25') - Looking For Advice'

Well it's time for me to actually follow though on a grinding room. With my new shop deployment I want to keep the dust down from day 1! I have a space sectioned off that's about 12ft by 6-1/4ft to turn into a grinding room. While it's not quite as wide as I'd like it to be I have limitations due to an attic door.

This is the basic overview of where I'm planning to place it in the shop:


I plan on putting a door and window (for light) on the 12' wall something like this (but the window will be 24x27 and door space...
  • Like
 
I did not mean the outer walls and doors. I was referring to the inner walls between the grinding room and the rest of the shop. Having both visibility and light coming in from the main shop area is really nice. If someone comes in the shop, or a person is working in the shop area while you are grinding, you can see each other. The storm door I mentioned is the door into the grinding room.
 
Yes I will definitely put windows between the grinding room and the general shop area.
And yes it will be fully closed, I do not plan to throw this together, plan on doing this properly.

I have maybe not phrased my question right, I am mostly interested on the dust collector it self.
As I have been making knives full time for years now, I have quite a good understanding on the general shop area and the grinding room setup I want.

But the dust collector itself is a bit of a unknown thing for me. I have not found any commercial available units here. Closest thing I have seen are dust collectors for surface grinders.
They would not be powerful enough for a dust collection system running multiple pipes etc
I have seen also a wet dust collector, with a water tank that takes dust into it, seems interesting, but very expensive.
Also dust extraction for blast cabinets might be interesting.
 
Here is what I have learned

- don't run a filter bag to recycle air, if you must use the bag put it out of that room and even better out of the shop in a "closet" to protect it from rain.

-don't use a collector on anything flamable then grind metal
 
Marko Veselinovic said:
Yes I will definitely put windows between the grinding room and the general shop area.
And yes it will be fully closed, I do not plan to throw this together, plan on doing this properly.

I have maybe not phrased my question right, I am mostly interested on the dust collector it self.
As I have been making knives full time for years now, I have quite a good understanding on the general shop area and the grinding room setup I want.

But the dust collector itself is a bit of a unknown thing for me. I have not found any commercial available units here. Closest thing I have seen are dust collectors for surface grinders.
They would not be powerful enough for a dust collection system running multiple pipes etc
I have seen also a wet dust collector, with a water tank that takes dust into it, seems interesting, but very expensive.
Also dust extraction for blast cabinets might be interesting.
Click to expand...
You can get hand operated sliding knife gates for ductwork and piping. You could use those or caps to close off the lines to whatever you aren’t using so you would only be pulling through one line at a time.
 
1) The dust collector system has one function in a grinding room - to remove the metal dust and grindings. Clean up the benches and floors with a large shop vac and hose.
2) The sparks are hot and can make a fire, so you need a preliminary stage to quench the hot sparks. This is usually either a cyclone system (Metal Dust Deputy) or a spark Bong. An inch of water in the tank of either takes care of any fire risk.
3) The dust then needs to travel to a collection point. The air flow is from a vac-blower unit. Most of us use a 1HP to 2HP blower, depending on the size of the ducts. The whole setup can be a large stand alone dust collector with a filter bag and a bottom bin, a blower with a direct discharge outside onto the grass, or a large shop vac hooked to the spark trap. The spark trap and dust deputy will trap 99% of the heavy particles, and what is left to discharge is mostly air. It can just be blown out to the yard in many cases.
4) The duct work should be smooth walled and 75mm to 100mm for most shops. any type of AC or dryer vent tubing is fine. Use smooth turn elbows and limit the number of bends in the duct between the grinder and the trap. Avoid corrugated hoses except where used to hook up tools like a bandsaw or other woodworking tools. Hot sparks will burn through the hose and the hose also traps the grit and creates turbulence. This makes the system less efficient. Make all duct runs as short as possible to the trap, and from there as short as practical to the collection container/bin. Never have the duct go uphill from the port to the vac-blower. This will cause debris to collect and reduce efficiency, and possibly start a fire in the duct. You can find all sorts and shapes of AC boxes that the duct can connect to. These are great for making the spark funnels and such. They are very cheap.
5) Have a separate system for wood sanding dust, chips, and sawdust. A large shop vac plugged into the catch funnel or tool dust port will take care of it. A separate set of ducts to a wood dust collector is a more professional system. Again, this can be small or large, depending on the shop and amount of wood dust. If you just do handles in the grinding room, you can use the same setup for the metal as long as the tank is emptied afterwards and fresh water put in.. Vacuum the funnel and bench area when done with wood and you will be fine.

Spark Bong - https://www.bing.com/videos/rivervi...3CC1C308F3F9434&mmscn=mtsc&aps=37&FORM=VRDGAR


Wood type dust collector; small dust vac with bag or discharge port; metal dust deputy; 4X10" AC register box
 

Attachments

  • 1752176165716.png
    1752176165716.png
    253.6 KB · Views: 3
  • 1752176191623.png
    1752176191623.png
    417.6 KB · Views: 3
  • 1752176241699.png
    1752176241699.png
    35.7 KB · Views: 3
  • 1752177071773.png
    1752177071773.png
    5.9 KB · Views: 3
ScarFoot said:
You can get hand operated sliding knife gates for ductwork and piping. You could use those or caps to close off the lines to whatever you aren’t using so you would only be pulling through one line at a time.
Click to expand...
I would be putting those in for sure, but there is still time where it would be handy to have two machines with dust collection "turned on". Now I am not sure, the length of the lines could also effect the sucking power?!
And a more powerful blower would not be a bad thing.
Stacy E. Apelt - Bladesmith said:
Have a separate system for wood sanding dust
Click to expand...
I would like to avoid that, the system should be as easy to use as possible, so I end up actually using it all the time. As you said in my case it would not be much wood dust, just the handles, and I do micarta mostly.
Stacy E. Apelt - Bladesmith said:
This is usually either a cyclone system (Metal Dust Deputy) or a spark Bong.
Click to expand...
These are great ideas, the spark bong would be a cheaper and easier, but it might get in the way a little, and I would need multiple ones.

Overall great advice!
I think I will go with a big blower with a a cyclone system to a steel drum filled with water, and the fine dust just to a bag filter. It will not filter the micron dust, but I will be putting the whole system in a separate room, so it is not a problem.
 
The length of the lines would have some impact but really you need to make sure everything is sealed well and the leg(s) that is in service is isolated from what’s out of service while you’re using it. When you’re talking about vacuum systems remember, a vacuum doesn’t move the material, it moves the air that moves the material. You just need enough vacuum to get the proper airflow from point A to point B. I deal with systems that have thousands of feet of piping but they all operate on the same principle. When things aren’t pulling correctly most people think they need more vacuum when they generally just aren’t getting enough airflow. Often it is because of air-in leakage or they’ve throttled the inlet air down too much. Minimizing air in-leakage throughout the system will help maximize how much you can pull.
 
Air speed is controlled by volume being moved and restriction. reduce the pipe size at the machine and the speed increases. Using a 100mm duct to the vac system and reducing it to 75mm or 65mm (3" or 2.5") at the machines/spark trap will increase the air speed at the machines. With a 2HP blower, you can easily run several machines. If using a water trap bong you can do wooden handles in the same system. The water will get sludgy faster, so dump it more often.

There are many past threads on building spark bongs and dust collection in general. Look through them before settling on where the ducts and such will go.
 
Spark arrestors for dust collection systems are readily available. They are not cheap though. We have a 3 Hp cyclone for each grinder in the shop, upgraded with FR treated HEPA filters and a spark arrestor between the grinder and cyclone. The air goes right back into the shop.

We don't work wood and metal on the same machine, and we clean out the system after grinding aluminum. YMMV
 
You must log in or register to reply here.
Back
Top