metal dust collection

[sethsacc]

Trying to figure out the best way to collect the metal dust and grindings from grinder, metal chop saw, and belt sander using my existing CV1800. Thought about a wye after cyclone going to two bins with separate blast gates but I don't think I can seal the gates. Anyone have any idea if a separate cyclone body placed inline with the duct that feeds the metal working machines (no impeller or motor) would work to separate out the metal dust first before entering the main ductwork? Or would a separate system using a big shop vac with the mini work better.

 

[bababrown]

I would have three concerns. The first is starting a smoldering fire. The second is melting plastic parts. The third is to get enough air velocity to transport the metal filings. A dust collector doesn't provide enough head (static pressure) to generate the air velocities you would like to transport metal filings. A good shop vacuum will provide 5 to 10 times the head though at lower air flows. Trying to share a dust collector also mixes sawdust with glowing embers --- something I would avoid. Also, the stream of sparks from a chop-saw is enough to melt plastic at close range. You need to cool the sparks before they contact any plastic. For a fixed grinder or sander you can use a few feet of metal ducting to let the sparks cool. The same would work for a large, fixed chop saw but you would need metal flex for a portable saw. I would stay away from a cyclone because the volume of dust in metal working is so much smaller than with woodworking. I'd just go with a good shop vacuum. One other thing I've noticed with my chop-saw is that a hard crust develops on the base of the saw where the sparks hit and also inside the shield. It will build up quite thick until I break it off. I'm sure it would be a nuisance in ductwork.
bababrown

 

[Kennyd]

As a hack metal worker myself, I have to agree that you don't want to be using your CV for your metal tools.