Grinder dust collection - a few questions

Jonas Liebel

Jonas Liebel

Joined
Jan 20, 2018
Messages
34
Hi there,

I finally chose to make a dust collection for my grinder, and I wondered whether that steel part at the front (whats the english term for it?) would make a good entry point for the sparks to get sucked in.

Does that look like a good idea or will most of the dust get blown out of it again?

If the collector bucket is filled halfway with water, would the whole system work without catching fire at some point?

If anyone has some opinions or experiences on this, feel free to let me know. :)

Best wishes,

JonasIMG_20190116_171019.jpgIMG_20190116_171145.jpg
 
I use an old gallon paint thinner can turned on edge. This gives a similar shape to the ss steam table tray you have. If I leave the entire top open I find the steel and grit tend to stick where they hit. A good portion of the dust will be sucked into the vacuum.
If I add an adjustable lid to cover the majority of the opening, this increases the velocity of the air being drawn in and improves the performance.
Jim A.
 
Looks good to me. Strategic placement of duct tape will improve the suction effectiveness around the top of the collection container. Here's a system I just started building with a friend. Most sparks are dead by the time they reach the plastic tubing.
 

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With my grinder here (almost ... one box was “delayed” by fedex :( )i have been thinking about dust collection, and found this recent thread.

Question: sparks from grinding metal and wood dust do NOT play well together. I currently have a shop vac sucking dust from my band saw (wood only). I am presuming i will need a separate system for the grinder used only for metal dust collection?

Related question is what do you do when you shift from sanding metal to finishing handles on the grinder? Change collection systems? I know one person said”most sparks are dead before they hit the plastic tubing - BUT i have enough experience with fire (and putting one out) that i do NOT want to come anywhere near creating one, especially in the enclosed dust filled space of the shop vac.

Final question: Jonas’s post shows a dust separator in the system. Is one really useful? Why not just go with the shop vac as the one and only collection point?
 
If you use a dust deputy (or similar cyclone separator) and put an inch or two of water in the catch bucket you will have no problem with sparks and any wood dust from shaping handles. On a dedicated wood cutting machine like the band saw and table saw, use a separate shop vac

Also, the more powerful the vacuum, the better the dust extraction and separation.Clean the vac filters regularly, too.
 
steel and aluminum dust is much more dangerous than wood and metal, i forget what the combination is called... one thing i see is that plastic hose will collect some dust and if it catches a spark, will smolder and possibly catch fire later. i had it happen. i use the same dust system and grinder for metal and handles. a spark bong keeps sparks from getting into the dust collector. yes the dust separator/cyclone helps your filter in the dust vac last longer because it gets less clogged.
 
You can eliminate all worry by placing the spark bong/dust deputy directly under the catch bin. I have a rectangular to round ductwork reducer going down in the trap. Plastic hoses from the trap will be fine that way.


Aluminum and steel dust is a similar mix to thermite. It will burn very hot, but needs a good bit of heat to ignite. Random sparks are not likely to start it. Few knifemakers grind enough aluminum to be a worry. If the dust goes directly into the wet trap, the concern is moot.
 
john april said:
i use the same dust system and grinder for metal and handles. a spark bong keeps sparks from getting into the dust collector. yes the dust separator/cyclone helps
Click to expand...
A spark bong seems like a good idea (but messy!). Question - the one video I looked at online (from Jess Hoffman) indicates that liquid/water does make its way in to the shop vac. Does the water leaving the spark bong interfere with the performance of the cyclone separator? My experience/training with these devices is that they are usually for dry dust systems.....
 
I have a vacuum cleaner similar to that. I tried it, but there's just too little volume/time so suck the dust away from the grinder properly. And I'd opt for a bigger collector as well. Go to Amazon and search for dust collection hood and you'll get some good options.
This is what I have. It's a dust collector specifically made for metall. I use a PU hose, the normal thickness one that flexes well.
I'd definetly not mix with wood/handle dust. All though the risk for fire may be small I respect it tremendously.
I'm getting a smaller separe collector for wood/handle dust with the same kind of hose and identical collection hood, it's going on the floor to the right of the grinder.

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Scaniaman said:
This is what I have. It's a dust collector specifically made for metall.
Click to expand...
Not sure if I have the space for a full up dust collection hood ... but then, funny enough, your space looks almost identical to mine, right down to the relative locations and spacing of the two benches and the placement of the drill press and grinder :) ). I did opt though for building a dedicated 2'x2' bench for the grinder .... i hope I did not make a mistake (am also thinking of positioning the VFD on the left side of the bench below the work surface (attached to cross-braces on the legs) - it seems like a well protected unit - hopefully not a mistake (i see you have yours on the wall).

Anyway - mine is not a production space ... just hobby - so hopefully capacity is ok? I might opt for your approach of two separate collection systems, one for handle material one for metal - unless someone else reading this can raise red-flags about that approach?
 
Take a look at a vortex separator, they are about the size of a standard shop vac and are powered by one. They seperate out all the solids so you dont damage your vac.

edit: Bad habit of not fully reading posts. Good luck!
 
Cushing H. said:
that is what I mean by a "cyclone separator" ... I believe different terminology for the same thing? Does seem like a good (and pretty inexpensive) addition....
Click to expand...
Yeah, same idea. I have one in my shop but it isn't quite set up, I was using an old industrial blower/vac thingy, but it just doesn't have the speed or volume needed for my uses.
 
Cushing H. said:
Not sure if I have the space for a full up dust collection hood ... but then, funny enough, your space looks almost identical to mine, right down to the relative locations and spacing of the two benches and the placement of the drill press and grinder :) ). I did opt though for building a dedicated 2'x2' bench for the grinder .... i hope I did not make a mistake (am also thinking of positioning the VFD on the left side of the bench below the work surface (attached to cross-braces on the legs) - it seems like a well protected unit - hopefully not a mistake (i see you have yours on the wall).

Anyway - mine is not a production space ... just hobby - so hopefully capacity is ok? I might opt for your approach of two separate collection systems, one for handle material one for metal - unless someone else reading this can raise red-flags about that approach?
Click to expand...

I'm also a hobbyist, just getting started in all this :) Of course using a vacuum cleaner is better than nothing. I did try it, with my collection hood, and honestly I'd prefer a large bucket with water instead. Sure it sucked away the dust that fell/shot into the hood, but it did not make the dust fly in there well enough.
 
Scaniaman said:
I'm also a hobbyist, just getting started in all this :) Of course using a vacuum cleaner is better than nothing. I did try it, with my collection hood, and honestly I'd prefer a large bucket with water instead. Sure it sucked away the dust that fell/shot into the hood, but it did not make the dust fly in there well enough.
Click to expand...
Hmmm. Just a big open bucket. No vacuum at all (i think i have seen this a couple times...
 
You don't need a spark bong if you use a cyclone (dust deputy) separator. The water in the bottom of the cyclone won't get into the shop vac or vac system if it is kept low enough and the incoming tubes are properly directed. If you put the catch pan/funnel directly feeding the bong or dust deputy with hose, the sparks and dust go straight in.

Using 3" PVC or metal ducting is far better than flex hose. After the separator, flex hose is OK, but you are still going to get better ait flow without all the turbulence caused by flex hose.
 
Stacy E. Apelt - Bladesmith said:
You don't need a spark bong if you use a cyclone (dust deputy) separator. The water in the bottom of the cyclone won't get into the shop vac .....Using 3" PVC or metal ducting is far better
Click to expand...
Oh - thanks for the clarification. I was not aware that the "dust deputy" can be fit to a bucket with water in it (I am used to thinking about cyclone separators on a much bigger industrial/dedicated scale, where they are run dry ). Cool ... I think I will try to go that direction. Agreed with the solid ducting for air flow ... looks like I will just need to play with the "catch" mechanism to make sure as much material is caught as possible.

Thank you all - this makes much more sense now!
 
In the photo from an earlier post, the dust deputy is on a bucket. Many are made to fit a drywall bucket. You can just set it on the top of a metal waste bin. There is no vacuum in the bucket.
They make an all metal dust deputy, including the bucket, for around $100.
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FWIW, this is what I am using. I've used a 5 gal bucket and lid in place of the igloo cooler for about 4 years and it was ok, But this igloo water cooler (garage sale $5) just works a LOT better than a bucket. The lid just fits better, and the vac tubes fit better and hold position better than with a thin bucket lid.
So my system: Spark Bong -> Dust Deputy -> Vac. I do wood and metal with no change in setup at this point.
The downtube in the igloo spark bong goes over half way down the bucket and about 4 inches of water in the bottom.

DustCollection1.jpg
 
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