Benchtop Fume Extractor Cuts the Cord, Clears the Air

What good is safety gear that isn’t used because it’s annoying and gets in the way of getting the job at hand completed? None, really, and the solder fume extractor is one item that never seems to live in harmony with your workspace. They’re often noisy, they obstruct your vision, and a power cord draped across your bench is a sure way to ruin your soldering zen.

To fix those problems, [Nate] has built a nice battery powered solder fume extractor that’s so low profile and so quiet, you won’t mind sharing a bench with it. Based on a standard 80-mm case fan, the extractor has a built-in 18650 battery for power and a USB charging port. There are nice little features, like a speed control and a low-battery indicator. The fan mounts to a pair of custom PCBs, which form the feet for the fan. [Nate] claims to have run the fan for 12 hours straight on battery before needing a charge, and that it’s so quiet he needs to add a power indicator to the next version. Also making an appearance in rev 2 will be a carbon filter to catch the fumes, but as [Nate] notes, better to spread them around for now than let them go directly up his nose.

Are you in the hacking arts for the long haul? Let’s hope so. If you are, make sure you’re up on the basics of mitigating inhalation hazards.

32 thoughts on “Benchtop Fume Extractor Cuts the Cord, Clears the Air

    1. The fan blade behaves a lot like a wing…if you add enough obstruction, you (aerodynamically) stall it and it stops moving air -> not doing as much work -> motor will run faster

      Thanks to the ever increasing demands in PC cooling, you can buy off-the-shelf “pressure optimized” fans (they have fewer, but wider blades with smaller gaps between them) as opposed to an “airflow optimized” fan (lots of skinny blades, with large gaps in between them)
      And because on the internet we have people reviewing…everything…, some even provide P/V graphs of reviewed fans ;-)

  1. Are there any BLDC fans with a separate control line? All I’ve seen were controlled with supply voltage. It’s hard to build an efficient (switching) power supply for a wide range of output voltage.

  2. We had a discussion about soldering indoors some days ago. I was told that there is not problem to remove smoke from the solder (like in kitchen / lab extractor hood – just a fan and a plastic hose similar to those used by portable air-condition units which you put out of the window) but that it would cool the air around the soldering iron and make the soldering more difficult.

    You might solve this using active fan with hot air + extractor but especially during summer days you would increase the room temperature…

    I was also thinking about electrostatic filter which might remove the smell without affecting the temperature…

    1. The smell is the least of your problems… If you’re using pure rosin, the smoke contains particles of varying size and composition, most of that will probably get caught by your nasal mucus tissues (after all that’s what it’s for…at least we think) and will come out as you blow your nose, but probably still not healthy to breathe. Also, leaded solder will release trace amounts of lead particles into the air when molten, not very healthy to breathe in…but there don’t seem to be cases of lead poisoning even in people that worked with it daily for years and years :P
      The newer, chemical flux, especially for lead-free soldering is a different story though, you’ll be glad if you get an MSDS that lists everything that’s considered harmful, so you can have “fun” reading what’s in there.

      p.s. you don’t need a draft in tens of meters per second, even a very light draft will suck the fumes away without affecting your soldering, you just need a positionable nozzle and place it in the right spot.

      1. Colophony lung is the occupational disorder associated with rosin solder ecposure in the small proportion of workers who develop an asthma like condition as a result of repeated exposure…

        The lead free stuff may be worse, as it is exposed to higher temperatures and therefore may have have a higher proportion of thermal degradation products.

      2. OK,
        I know it is not just about the smell :-) Luckily I am not the guy who is soldering (I have poor vision) but we had a discussion with few guys who sometimes have to solder in common office room as they do not have appropriate workshop available.

        So in fact some transparent hood with a plastic hose and PC fan could significantly help.
        My another idea was whether it is possible to remove at least most of the dangerous particles from the fume without need to have an exhaust hose from the window.

        Maybe some DIY filter – e.g. forcing the exhaust air through wet textile labyrinth so the particles would stick to the walls…

  3. ​I was wondering how long it runs on a full charge?

    I use a variac and a 120 volt fan with a carbon filter, but it’s showing it’s age and is starting to rattle. I do like the lower noise of modern PC fans (the 120 volt fan I use was taken from stock for an 8.8 kW (peak 13 kW) industrial brushless motor driver. I used to service them at my old job). Great flow, but it comes with noise. I always crank the variac down to around 70-80 volts, just to reduce noise, but it’s right at the threshold of “sucking range” when cranked that low. I tend to have to get the fan right up on it then. Even with just 5-10 volts more, it stops sucking (by sucking even harder), but then the noise just blows…

    I ask about the battery life though, cause I often solder for hours a day, sometimes longer than 8 hours. I could always invest in a battery charger of some kind, to keep the batteries topped off, and then swap as needed, but then again, I could also get a 12 volt wall wart too. Those cords are much thinner than the thick 120 volt cable that sometimes ends up with my fan knocked over by the weight of the cord. I do like the mobility factor though. I could move it to other spots to work. It’d also free up my variac.

    I’d also like to reuse my carbon filter housing, which is a 120mm plastic piece that bolts to the fan, and has a snap off cover to retain the filter. It’d make sense then for me to buy a 120mm PC fan. I suppose that’d use even more power yet… Course, bigger could also mean bigger batteries too.

    1. Using a Panasonic NCR18650B I’ve gotten 12 hours out of it at full speed. It also supports being powered from micro USB with no battery, or charging and running the fan simultaneously. Mileage will vary with lower quality batteries. This will be significantly less airflow than your implementation above, this one is approximately 2W but when placed several inches from your project, it removes fumes quite nicely with very little noise. At some-point I plan to make a version to sell which supports either 120mm or 80mm fans and possibly higher power as well.

  4. As someone who has developed a severe reaction to the water-soluble fluxes (nerve pain, fever/chills, etc) don’t mess around with solder fumes. I ended up buying a rigid shop vac (inlet/outlet ports), and creating a PVC manifold system and flexi-pipe that sits on the back of my bench. One nozzle goes next to my work, another sits over the iron rest, and a third is capped. The exhaust gets piped out the window….. Not a single reaction since……

  5. I prefer our expensive professional solder fume extractor (Weller Zero Smog) with multi stage filter. But for those who like to cheap out, blowing the fumes around in your room or trying to scrub the air with “DIY carbon filters” is probably still better than inhaling it directly from the tip of your solder iron.

  6. I bought a $3 mini deskfan, duct taped it to a 7′ (2.13m) section of dryer vent hose, and attached the end of that to a board that notches into my window frame.
    As long as i position it right, everything ends up outside.

  7. “Also making an appearance in rev 2 will be a carbon filter to catch the fumes” – actually you need a much more powerful fan to push enough air through a filter. Similar commercial systems have fans more like 20W not 2W.

    1. It’s all quite relative. I work on quite small projects, and don’t need an extractor that covers a large area of my workbench. This one removes fumes quite well within 6-8″ with an active carbon filter on it. At the time of posting I did not have any filters to include in the images. I find the small size, portability, and lack of cable clutter outweigh the sound and bench space of larger and more powerful commercially available solutions.

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