My DIY Soldering fume Copper welding flux smoke extractor is not pretty, but quite effective.
This is a Delta 92mmx36mm ‘server fan’ is rated at 7500 RPM fan, at 12vdc.
Very high CFM(175), and static pressure rating.
It is OK with upto~15v, but will smoke itself in the 15.5v+ range. I have prevented this possibility and can safely feed it upto 31ish volts.
This cardboard box is from a 1 liter insulated water bottle. it happened to nearly perfectly fit the 92Mm fan like it was meant to be there all along.
I first intended to use the fan as a pusher, to suck stray rising fumes inside then filter them, but it worked far better as a puller, Sucking the fumes and smoke at the rectangular filter.
I judged this by the fan noise, and the perceived air flow when positioned in both orientations, and then when watching the solder smoke rise towards it.
The battery feeding this gilter, in the photo, is just a 3S1P 2000mah 10 amp 18650 that I repurposed from a 36$ free shipping 7s1P Parts only esk8 I bought, in late 2023. My first ever spot welded pack.
I found a roll of high quality duct tape on the sidewalk of the bridge the other day, and used it to reinforce/ seal the cardboard box, then cut the hole for the HEPA filter, and taped that to the box, Velcro cinch strapped the fan to it, and Yeehaw.
Almost Elegant in its simplicity and function.
I use a modified voltage bucker as a the fan’s speed controller.
Easily Finger twist the desired fan speed/ noise/ amp draw / airflow.
This has proven very reliable, I have a few fans running for several years now, continuously by one of these. There are some tricks to achieving this longevity, that I can share.
This specific fan I have velcro attached to one side and then more onto a 18V powertool battery and can use it to effectively blow sawdust on the floor, from Waist level, out of the garage, or place it under my T shirt and impersonate the Michelin man, to cool off, or Aim at Fiona’s belly.
It can be repurposed for those tasks as easily as removing the velcro cinch strap.
The rectangular HEPA filter cartridge is held to Cardboard body mostly with the tape, and the activated Charcoal filter, 3 layers of it, is held to the unit with Velcro cinch straps, and the one binder clip.
At full speed it is insanely loud and powerful, but at less than half speed easily sucks in any rising smoke when positioned directly above the workpiece.
At low speed, it is whisper quiet and placing my hand in front of the filter, I can still feel air still getting sucked past.
Light and portable, I can easily reposition it.
I have a bunch more charcoal filter I can cut to size and easily replace when contaminated, and 3 more unused HEPA cartridges too.
Now there are no more good excuses to not to Solder and Spot weld at my interior workspace.
I’d wanted to extract all undesirable fumes and pump them to the attic or outside the window, but this works well and should be lung safe(r), as long as the filter is not clogged, and the activated charcoal pre filter is relatively fresh.
I have a different Filter using a Shop-Vac cylindrical HEPA filter, but the unfocused radial suction made it far less effective at capturing smoke and fumes, and it was far clunkier to position, and could be partially clogged from previous use too, as the lesser surface area of the new rectangular HEPA filter cartridge seems to flow way more air.
