Separator used with a benchtop grinder

[tman02]

I would like to know if one of these separators would be safe to use attached to a benchtop grinder that is used to sharpen lathe tools. I really don't want to have to buy another shop vac, and am hoping all of the dust from the grinder wheel will stay within this separator.

tman02

[WayTooLate]

T-man, 
Yes and No.  (How is that for a 'definitive maybe'?) 

The separator will separate the 'grind dust' from your bench grinder.  Since the metals you are grinding are a higher molecular weight, they are easier to remove from the air stream than the lighter wood dust. 

There are two potential complications.  The first is that the metal debris is much sharper and irregular than wood dust.  While wood dust likes to 'bridge' across openings and pile up in corners, it doesn't 'grab' real well.  However, metal fines are able to imbed and latch onto each other with greater tenacity.  You will find that the metal particles will find more nooks and crannies to imbed themselves and cling much harder than with wood dust. 

The second issue is with metal by-products.  When wood working, you should not expect to find bits of your blades and bits in the dustbin.  The debris collected from grinding is a conglomeration of wheel debris, and the different metals, plating, paints and other assorted items that go through your grinder. 

My bench grinder has a squirrel cage blower mounted behind the grinder that went into a ~15cu ft reusable fabric bag.  The bag gets clogged with fines and starves the airflow.  Cleaning the bag is a 'hazmat experience' .  I started to use a Thein separator to drop out as much debris as possible.  But when I saw how contaminated the separator was becoming, I couldn't bear to see my wonderful separator being defiled. 

So I bought a $30 (on sale) DD and mounted it to a plastic bucket.  I don't care how disgusting the little cyclone gets.  I can wipe out the bucket several times before I have to clean the bag again.  It is a filthy system that works well enough not to have to share it with anything else. 

That has been my experience - I hope it helps!
- Jim

[tman02]

Thank you for your reply.

This separator would only be used with my bench grinder so I would not care how ugly it becomes.

My only concern is I would be using it with a shop vac that also is used for collecting wood dust and chips (from my lathe) and worried about starting a fire in the wood particles.

But from what I read on the posts the grinder debris should never reach the shop vac or if any of it does would be cool enough to not be a problem - yes or no?

tman02

[alan m]

i wouldnt worry about making the seperater ugly.
it will only  be on the inside
i think the metal particals might wear through the side of the seperater.
i would make the seperater out of something solid rather  thin  plastic

i would be worried about hot particals getting through (or the spark) and setting fire to the vac.

some companies  sell a box that will catch the spark.
festool sell one  as far as i know

[WayTooLate]

T-Man,
Famous Last Words from a Red-Neck:  "Hey Y'all, ...wonder what this will do..." 
After your shop burns down, having a separate shop vac, will be a lot less than your deductible. 
We all have to live within a comfort zone of the risks we take - you have to be comfortable with yours... 

As for me, I don't EVER worry about static sparks igniting my dust collector - I believe it is an urban legend.  There are documented studies where engineers TRIED to ignite the moving dust flow and failed.  However, dust explosions from other sources of ignition are real - and disastrous. 

On our grinder, we have a cloth bag that will not ignite, but will support combustion - like almost every other cloth bag on dust collectors around the world.  We don't have ANY evidence that a grinding spark, can come close to following the duct, going through the blower, swirling through the cyclone and maintaining anything close to the heat needed for combustion. 

When dust fires DO occur, they seem to be doubly tragic because they typically smolder for hours before turning into flames.  It doesn't ignite while you are working nearby and could easily extinguish it.  It always seems to wait until it is unattended and can spread significantly before being detected. 

A good smoke detector should sniff that out before it bursts into flames - a good idea in any shop. 

I would consider the risk to be QUITE minimal, but they thought the same thing about the Hindenberg! 

Hope this helps!
Jim