12 volt motor

[wadebevan]

FYI, I placed a strong magnet below the base of the rest on my kally... I learned this is not a very good plan because the dust collected, then caught fire (well, it caught 'smolder'). It was a deep red all the way to the center of the little dust ball.

[SHARPCO]

FYI, I placed a strong magnet below the base of the rest on my kally... I learned this is not a very good plan because the dust collected, then caught fire (well, it caught 'smolder').  It was a deep red all the way to the center of the little dust ball.

What if you put a wet towel(or paper towel) on the magnet? Spraying water on the towel from time to time will prevent the fire from coming on.

[wadebevan]

I think it would probably still smolder.
The magnet collects the dust pretty effectively and it builds up fast and the outermost surface of the dust ball would probably be exposed to enough sparks to ignite.
Standing water seems most effective for a DIY 'home shop' solution.
So, I have a stainless bowl with a few inches of water in it and a magnet at the bottom.
The magnet serves two purposes, sticks the bowl to the base plate, and draws the dust in.
Not sure it is the perfect solution, but so far it has helped.

[Mark Reich]

Thank you for posting the fire danger warning, Wade. I'm not sure if there is a more important message. People burn their shops down at an alarming rate. You are right, standing water is the safest and most effective spark arrester.

[SHARPCO]

Thank you for posting the fire danger warning, Wade. I'm not sure if there is a more important message. People burn their shops down at an alarming rate. You are right, standing water is the safest and most effective spark arrester.

Mark.

Can I use woodworking dust collector for blade sharpening?

[grepper]

Mr. Sharpco,

Wood and metal dust collection systems are in principal basically the same.  Please see:  

http://www.bessex.com/forum/showthread.p...34#pid4434

However there are very important safety considerations:

It is not a good idea to use the same system for wood and metal dust collection.  Mixing fine metal particles with wood dust can be real fire hazard, especially if any oil mist and/or sparks are involved from the metal grinding.  Fine metal particles will oxidize, and wood dust combined with oxides of aluminum and steel, especially combined with oil and/or varnishes and glue from wood is a recipe for disaster.  

Additionally, very finely ground iron rich metal particles are pyrophoric, meaning the can ignite by simply being exposed to aerobic environments such as air.  This is not the same as glowing sparks produced by the friction of grinding.  Unless the goal is a fire, mixing pyrophoric combustible metal dust, glowing sparks from grinding friction, wood dust and varnish residue is contraindicated.

http://bessex.com/forum/showthread.php?t...60#pid4260

Another difference between metal and wood dust collection systems are the types of filters used on the output side.  Metal dust can be extremely fine and is not beneficial to inhale.  Metal dust filters are very fine and can be expensive.  If possible it’s best to vent outside the workspace so only our backyard friends like beautiful birds and delightful little chipmunks in the vicinity of the exhaust can be adversely affected.  

While venting outside and specialized metal dust collection systems can be logistically and/or financially prohibitive respectively, a simple cyclone separator and/or forcing the collector airstream at the surface of water can go a long way in both fire prevention and greatly reducing metal dust in the shop environment.  These simple systems can be constructed for a reasonably minimal cost as I mentioned in the first link above.

It's way better to at least do something rather than nothing.

[SHARPCO]

Thank you so much grepper. 

In fact, I bought a woodwork dust collector a few months back and was afraid of the fire and refunded it. The reason I bought woodworking dust collector was because I couldn't buy metal dust collector at reasonable prices here in Korea. 

So I solve the dust problem in two ways.

First, if possible, I remove the metal as much as possible with Tormek and move to the belt grinder. 

Second, I use magnet. I wrap a 100 mm x 25 mm x 10 mm neodymium magnet with a wet towel and place it 2 inches behind the edge. When the metal dust is accumulated in one spot, I push it to around. And I often sprayed water here to prevent fire. But I have never experienced a problem, although I have forgotten to spray water several times. 

These are quite effective, but I think it's less effective than using a dust collector.

[grepper]

No need to fear a dust collector. Just understand how it works. A magnet works but won't eliminate environmental dust nearly as well as dust collector air flow sucking dust away.