# Can a rigid shop vac be used on my mini surface grinder?



## ome (Nov 10, 2013)

Hi guys,
i recently got a sanford mini SG WITH 4 inch wheels.  Can i use my large shopvac to pick up any metal dust that gets around the spark plate. 
Thanks,
Jon


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## kd4gij (Nov 10, 2013)

Shure but you will wan't a good filter in it.


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## Holescreek (Nov 10, 2013)

If you are going to use it make sure you have at least an inch of water in the bottom of it and surround the filter with a material that doesn't burn.  That way any heavy particles that may be still sparking will drop into the water and the lighter dust won't start a fire.  Fine grinding particulate steel will burn by itself when introduced to a good spark.


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## astjp2 (Nov 10, 2013)

Realistically, no.  What you should do is spray coolant on it and then filter the coolant for reuse using a sediment tank and skim off the clean coolant from the top.  Grinders are just messy, we have 2 at work, one from 1954, the other from the 80's.  Vacuums have inherent problems like wanting to explode with flammable dust and adding water can cause heat in the tank when the iron starts to corrode.  Just something to think about.  Tim


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## Pacer (Nov 10, 2013)

Not a good choice - you really need coolant on a SG - youll have burn/hot spots all over the place and your wheel wont have a very good life span


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## pdentrem (Nov 10, 2013)

I would place a separator between the vacuum cleaner and the SG. Easily made using a 5 gallon pail and one extra hose. That way most of the particles will stop there instead of all getting to the vacuum cleaner.
We have 2 SG at the shop, we use a Q-Air collection unit. It has a metal screen that sits on top of a collection pan, the pan has a drain for return of coolant, the second stage is a set of vertical filter bags. We don't use coolant, all of our tooling is ground dry. We use soft wheels so burning is reduced but resurfacing the wheels is increased. 6 of one, half a dozen on the other.
Pierre


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## Holescreek (Nov 10, 2013)

What you have to remember is that there are two categories of grinders commonly found in a shop, to keep it simple you have "water grinders" and "surface grinders".  Water grinders typically have a self reciprocating table and sometimes have automatic down feeds (but most are manual). Surface grinders are usually found with all manual controls and are meant to grind dry, though I occasionally use a "cool gun" (cold air gun) to keep the material temp under control if I'm going to be hogging.   Coolant on a surface grinder could quickly destroy it, water grinders have the proper sealed bearings and way protection built in.  I'd kick someone out of my shop if I caught them even running a coolant mister on my KO Lee 618.

Burn spots on a surface grinder indicate wheel loading and or the wrong wheel selection (to keep it simple).

The issues with surface grinder dust collection come down to health and safety. From a health standpoint, breathing silica is bad. Google it. Surface grinders require suction of around 650 cfm to pull the dust away from the operator. Many shop vacs fall into the 150~250 cfm range. Safety us most usually addressed relative to the noise issue.  Look at the dB rating of the vacuum you choose. Many yeas ago when I investigated the issue for my home shop Fein made the quietest vacuum but it was still around 100dB.

I ended up looking at it from a long term standpoint and am glad I did because I've added a T&C grinder and a Deckel SO grinder since.  I chose to make my own Torrit style dust collector using the impeller assembly from a Harbor Freight wood dust collection system which was rated at 650cfm.




In the photo above, the dust is collected in the 2" grey hose and enters the lower chamber behind a false wall that extends down towards the bottom  of the box stopping about 3" from the bottom. The heavy dust drops into the metal tray and the light dust gets caught by the 5 micron bag units as the air is pulled upwards by the impeller. Anything that makes it through the bags gets caught by a HEPA filer that is mounted over top of the bags. he clean air is then pulled through the impeller and shot up through the eggshell lined foam chimney.  Sending the air up through the chimney puts the expelled air out well above my ears and the foam lining quiets the noise to about 75dB.  I'v been running this unit for 10 years now without a hiccup.


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## ome (Nov 11, 2013)

Is there a dust collector that is portable so i can use it on a few different machines?
thanks, 
Jon


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## Ray C (Nov 11, 2013)

You mean, like this one? http://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html

In conjunction with this kind of hose?  http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
Ray




ome said:


> Is there a dust collector that is portable so i can use it on a few different machines?
> thanks,
> Jon


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## ome (Nov 11, 2013)

Ray C said:


> You mean, like this one? http://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html
> 
> In conjunction with this kind of hose?  http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
> Ray


Thanks Ray,
that looks like the price is right,  but will it get the dust from a surface grinder, as well as any fumes from a spot welder. I have most of my grinding machines in one room, with only one window
to open. I have a full face mask with cartridges and a heap vacuum for any carbide I may grind, but my baldor carbide grinder are in a different room with my other delta grinder for HSS. 
THANKS,JON


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## Ray C (Nov 11, 2013)

This does a fine job when I surface grind.  There will always be some residual dust in the immediate area of the grinder table and mag chuck.  I run this thing enclosed in my shop and I do not find dust in other areas.

Welding fumes are a different matter all together.  If you're concerned about welding fumes, I suspect this unit would serve as a good fan to suck air from one place and blow it out a window.  As for protection from organic poisioning, for that, you need a well fitting and appropriately outfitted face mask.


Ray




ome said:


> Thanks Ray,
> that looks like the price is right, but will it get the dust from a surface grinder, as well as any fumes from a spot welder. I have most of my grinding machines in one room, with only one window
> to open. I have a full face mask with cartridges and a heap vacuum for any carbide I may grind, but my baldor carbide grinder are in a different room with my other delta grinder for HSS.
> THANKS,JON


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## ome (Nov 11, 2013)

Hi Ray,
thanks alot, for the links and info. I have a good full face mask and sounds like once i get thise two products for dust collection and to direct the fumes from the spotwelder to the open window. 
Great idea.  When i srarted looking at some of the brand name dust and/or fumes were close to 1000. Or pricing was unavailable, which is probably more. 
Thanks again,
Jon


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## yendor (Oct 29, 2015)

I'm confused by the design above.

Do the Bags NOT Collapse on themselves and limit the surface are for dust to be collected upon when the System is turned on.
It looks to me like the direction of the airflow is wrong for the way the bags are mounted.

For this to operate efficiently it would require the bags to be mounted upside down so the bags would expand with air flow not collapse, and the HEAPA Filter to be suspended above them.

or is it just me ?


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## JimDawson (Oct 29, 2015)

yendor said:


> For this to operate efficiently it would require the bags to be mounted upside down so the bags would expand with air flow not collapse, and the HEAPA Filter to be suspended above them.




Normally bags set up like that have a frame inside to keep them from collapsing, at least the big ones are built that way.


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## Holescreek (Oct 29, 2015)

I put pieces of broken bricks inside my bags to keep them stretched.  Works great!


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