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I plan to build some sort of basic extractor ,and after seeing all of the 'contraptions' others have constructed(and how half-assed those are),what I have not seen used is an adaptation of a small vacuum cleaner. I an wondering why that is...... It seems to me that the addition of a charcoal filter element,and/or possibly a water chamber for collection would suffice. Has anyone here built an extractor ?
 

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,what I have not seen used is an adaptation of a small vacuum cleaner. I an wondering why that is......
You need LOTS of CFM,, a small vac has very few CFM, but, it has force,
no force is needed to move fumes,,,

Use the highest CFM contraption you can find,, a furnace blower,, etc,,,

I have a 24X24 inch belt drive blower in the rafters above my welding table,
that blower will evacuate ALL the fumes welding creates,,
I have it directed at the drive through door,, It is amazing to see how that blower will move fumes,,,:good2:
 

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Yup. ShopVac's biggest vac only moves air at 150 CFM. That's pretty low end. You can easily find an inline fan that will move 600+ CFM at any home improvement store and significantly larger than that at an industrial supply store.

Are you dumping this back into the room you'll be welding in? Why the need for a charcoal or water filter?

My neighbor picked up a restaurant exhaust hood for short $$ on Craigslist and just vented it through the outside wall of his garage.
 

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It also depends on how far away from the "collector" you will be welding.
Some Ive seen can be moved right next to the work, in which case you dont need nearly as much CFM.
If its something to the rear of a station, youd want as much as you can get.
Im going to have something similar, but only to create a draft through the garage.
For the bench, I had bought an old Jenn Air downdraft cooktop exhaust fan. Those things are crazy powerful and move a TON of air. I have two of these, and will use them as a way to clear the air in the shop from other projects, or just to have air moving at both ends.
For my current plan for the welding fumes, it will be a furnace blower directly behind where Ill be welding.
I generally weld near the door, so its usually not a problem, but in the Winter with the doors closed it can get to be a problem pretty quick.

Ill be following this for any better ideas!
 

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I put a 6" inline duct exhaust fan in the ceiling of my welding room, and a furnace blower fan on the outside blowing in. My room is 15x15' inside of my larger pole building, so the furnace fan sucks clean air from inside the general portion of the building and pressurizes the room. The other fan blows outside. I will also wear a respirator for larger jobs or welding anything with a treatment like galvanizing or anodizing. 3M Half Facepiece Reusable Respirator 6200/07025(AAD), Respiratory Protection, Medium(Pack of 1): Scba Safety Respirators: Amazon.com: Industrial Scientific
 

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I put a 6" inline duct exhaust fan in the ceiling of my welding room, and a furnace blower fan on the outside blowing in. My room is 15x15' inside of my larger pole building, so the furnace fan sucks clean air from inside the general portion of the building and pressurizes the room. The other fan blows outside. I will also wear a respirator for larger jobs or welding anything with a treatment like galvanizing or anodizing. 3M Half Facepiece Reusable Respirator 6200/07025(AAD), Respiratory Protection, Medium(Pack of 1): Scba Safety Respirators: Amazon.com: Industrial Scientific
Good point there to remember, if you are exhausting to the outside, you need to have an intake somewhere to allow fresh air back in, otherwise your exhaust number will be drastically reduced.
 

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It's also much easier to push air than draw it. This does assume you have an enclosure like a room, but there is a reason fire departments use positive pressure ventilation far more often than negative.

With welding (assuming you're using a shielding gas) you do need to make sure you aren't moving too much air across your work piece. My room works well with the furnace fan on low, if I use any of the higher settings it's usually only when I've forgotten to turn it on and want to clear a build up. And that usually only when I run my smoker in that room in the winter.
 

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Find a squirrel cage from a forced air heating system. I've used one in my shop/welding area over 25 years. They're cheap, easy to maintain, and the CFM can be changed by changing the pulleys, either on the cage, motor, or both. I built a shelf from wood to mount on the wall, with plywood on top. I used four rubber stand-off isolators for bolting the squirrel cage down to it, then cut a hole the size of the exhaust of the cage to the outside of the structure. I boxed that in, then made a fancy screened-wooden vent to trim it off outside, then painted to match the trim of the shop.

If you can find two of the same style squirrel cages, the second can be gutted and split in the middle, and fashioned to fit on the sides of the working cage, to extend away. At that point, add one or two 90° furnace elbows and attach hose to run the ventilation anywhere you need it :thumbup1gif: The system is pretty quiet.

Another thing for the hose, if you have high ceilings or open rafters, make a lightweight turnstyle (Example--upside down steering wheel with Brodie knob) and hang it above. Put a piece of pipe on it. At the outer pivot (Brodie knob) attach your hose and let it hang down, for better usability about the area your welding in.

My ventilation system also serves to dust collection in my wood shop. Another use for the hose system, for venting out exhaust (with hose) and paint fumes.
 

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Discussion Starter #11
RE:fume extractor

My thanks to all of you for your replies and suggestions. As my shop has a fully finished interior, collecting dust,debris,and in this case fumes/soot is important-hence the thought of a device that is portable and 'point of use' so to speak.A professional grade of collector such as the ACE that was suggested would likely be the best choice;the only negative that I see is it's physical size and the necessary storage out of my way when not needed(which would be 95% of the year,as my welding needs are only occasional).
 

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My thanks to all of you for your replies and suggestions. As my shop has a fully finished interior, collecting dust,debris,and in this case fumes/soot is important-hence the thought of a device that is portable and 'point of use' so to speak.A professional grade of collector such as the ACE that was suggested would likely be the best choice;the only negative that I see is it's physical size and the necessary storage out of my way when not needed(which would be 95% of the year,as my welding needs are only occasional).
You won't regret adding a piece of proper equipment to compliment your other proper equipment. Ace does make smaller products or there are other brands. Regarding its physical size, it will get used up holding clamps, etc. You can't beat having a safely made machine that won't burn the place down. Look for used to save a few bucks if needed.
 
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