Some of you may know that I may have a medical condition that has been associated with many things, including exposure to metal dust. While it's not certain this is the case for my situation (and it may never be fully established) I thought I would set up some sort of metal dust catching system to try and reduce my exposure. I should mention the condition I have probably also requires one to be allergic to metal dust and I know I am allergic to nickel dust.

I have what I consider good wood-dust extraction in my shed, plus 2 x 1000+ CFM ventilators, one ventilator is attached to my welding booth and one is high up in the middle of the celling to vents hot gasses from the shed when I run my forge/furnace. Despite these, I'm pretty certain most of the metal dust I'm exposed to comes from a multitool linisher because that is invariably where I end up tidying up various bits of metal I cut etc. The linisher sprays dust forwards and while I do wear a full face shield dust gets all over my hair and clothes. I have also started to wear a mask when using it.

I have up until now occasionally hooked a 100 mm flexible duct from my wood working dust extraction under the linisher just to help keep the dust levels down. Although the risk is very low that sparks may get into the dust extractor, a much bigger risk is a piece of hot metal getting sucked into the system and starting a fire.

Anyway, after much mucking about and changing my mind here is what I have come up with.
Its basically a metal chip catcher attached to my wood dust collector on one side and a sort of heat resistance snorkel arrangement on the other side
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The chip catcher is a 20L metal drum - I cut the top off right where the drum tapers and then inverted the top and its natural taper fits tight against the inside of the drum. The top is held down by 3 of those cantilevered clip things you find on caravans making a solid tight seal

The connections are 100 mm galv down pipe/gutter connections, just pop riveted to the drum lid.
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The input side ducting is some left over aluminised Mylar film flexible ducting typically used for connecting kitchen range hoods. With a rating of only 130 (I think it can take a bit more than that) I realise this won't last all that long especially if a HD stream of metal dust is sprayed onto it but it will do while I source some proper Al flexy ducting. There also some excellent High temp ducting around but the one place that sells it here in WA has a minimum buy of 20m!

The reason I wanted the input ducting flexible is because I want to be able to adjust the "snorkel" as shown for different grinders etc.
Like this. The inlet is another one of those 100 mm galve drainpipe/gutter connectors.
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And this

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That corrugated ducting and a chip catcher really stymies the air flow but I'm at the point where something is better than nothing. Ideally I'd like a linisher oriented to operate in the vertical direction so that it sprays its dust down into a steel chamber that is sucked on by a 150 mm duct connected to the shed dust extraction system. However I have many more things on the todo list to attend to at the mo.