Exhaust venting & buff dust

Thoughts if someone had the time. I’m planning on stepping down in size on an exhaust blower I used previously as I believe it’s too big for my new area. I was using a 6” 460cfm blower to vent fumes & had it tied into my old buffing station. I intend to step down to a 4” 170cfm. I use a Y that I can close off the run to either the buffing collector or soldering area or both when not in use. Since I am back in my house with fabrication the 460cfm would be overkill & too much negative draw on the house & would draw on too much outside air from anyplace it could (mostly from my cat door)
I do plan on installing a dust collection baffle (storage container with a filter or bag). I vent out through the ceiling into the attic then a duct through the wall.
My question is do you believe 170cfm is sufficient? I plan to close off soldering or buffing line to isolate either I am using at the moment. Much appreciated thank you

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Man id love to knpw how to set that up.

I have a 900 cfm blower that ventilates my polishing hood through a coarse polishing duff filter then is vented directly to the outside through a 6" metal flex hose. My shop is a lot cleaner than it used to be. I have an inexpensive stove hood over my soldering bench that is also vented directly outside. I need to add a powered vent over my casting and resin working areas. You can see these two systems on the Shop Shots page of my website.I feel like I provided this same reply recently. There may be a similar discussion in progress…Rob


It’s somewhat simple & basic Kim. You can find inline exhaust vents fairly cheap now days & the duct lines all on Amazon. I can send you a list of what I’m ordering & you can get an idea. A drier hose & a small blower will work to keep dust & fumes out of your work area.

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Also look at websites that sell small green house ventilation products. For me the hardest part is cleanly cutting a hole in the side of the cellar wall to pass the vent hose through to the outside and then finish it with a vent hood…Rob

I have a small set up i did for around $100 for soldering, but want to build something more into my wall or windows.

Oh the stove hood is a great idea!

I have a kitchen stove vent that exhausts to the outside, for my stove… this is a 1970’s exhaust system. Modern vents all have filters that need to be changed regularly. External venting kitchen hoods are hard to find and even harder to get cleaned… only one service company was able to remove the grease in the hood and exhaust pipes…grease build up wouldn’t be a factor for a jewelry bench, but accumulated dust could be.
If this is a DYI project, be careful of making holes thru the wall or ceiling… they have to be sealed well to prevent rainwater and snowmelt from intruding, especially if they come out through the roof. They also are areas of heat loss in areas with cold winters.
External venting however is a necessity when dealing with fine dust and potentially hazardous materials… large capacity systems will move more air and keep things cleaner but at the cost of blowing out warm air outside during the winter… not a significant problem in warm climates but definitely a factor in the upper Midwest where winter temperatures drop below zero…don’t know whether this makes sense or not, but it’s empirical…

I just took the filter out of mine when I installed it. An outside vent hood (think dryer vent) is a good idea to keep out the rain and wind. You might also add some coarse screen to keep the birds and mice out…Rob

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I had my dryer vent redone… it comes with a screen and an automatic spring loaded shutting door, and a hood…standard equipment. A on fashioned stove hood with external venting placed over the work area would be ideal…you won’t have to get it cleaned for grease from frying food…I can’t find the rating on CFMs on my stove hood because it’s so old…the motor is an induction motor that is huge for it’s capacity and takes a while to spin up… another piece of antiquated equipment that still works…the external vent also has a hood, screen and a self closing spring…
I have no idea of whether modern, filtered no external venting stove hoods could be modified for external venting… if they could, they would work well over the work area of a bench…

Following should be a link to the modern equivalent of the hood that I bought 25 years ago. It wasn’t much cheaper than the new one…Rob


And make sure to check the screen often, to make sure that it’s not getting clogged.

But save the polishing duff. You can send it to your refiner along with other scrap and they can refine out the metal that you have removed in the polishing process…Rob

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I am in the process of adding a third outside vent to my shop. This one will be directly over a bench that I use for casting, running my PUK and pouring resin. In a modern built house like mine, the biggest challenge to this job is drilling the hole in the side of the house. A 4.25" circle saw and arbor cost close to $50 to buy. I just hired a guy to do it for $20. I drilled the pilot hole to show him where to drill the hole. I have an older inline greenhouse fan that will fit up inside the floor joists and allow a direct and very short run of vent hose to the spot that I want to ventilate. I do have to do some electrical work to get it on a switch. Until then I can just plug or unplug it. The down side of all this ventilation is that I am blowing heated air outside. It also has a slight negative impact on the radon system vacuum…Rob

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Definitely save the filters. I was chatting with a fellow who had bought a polishing station at an equipment auction. He basically got the machine for free - because the filters hadn’t been changed in several years.

This project is done. I can now exhaust my casting, resin pouring and PUK bench…Rob


We used 400cfm for a double sided lathe using enclosures. Half that was not sufficient, too much lint swirling around and not enough draw.