There are plenty of chemical processes that happen commonly around the house that, if we’re really following safety protocols to the letter, should be done in a fume hood. Most of us will have had that experience with soldering various electronics, especially if we’re not exactly sure where the solder came from or how old it is. For [John]’s electroless plating process, though, he definitely can’t straddle that line and went about building a fume hood to vent some of the more harmful gasses out of a window.
This fume hood is pretty straightforward and doesn’t have a few of the bells and whistles found in commercial offerings, but this process doesn’t really require things like scrubbing or filtering the exhaust air so he opted to omit these pricier and more elaborate options. What it does have, though, is an adjustable-height sash, a small form factor that allows it to easily move around his shop, and a waterproof, spill-collecting area in the bottom. The enclosure is built with plywood, allowing for openings for an air inlet, the exhaust ducting, and a cable pass-through, and then finished with a heavy-duty paint. He also included built-in lighting and when complete, looks indistinguishable from something we might buy from a lab equipment supplier.
While [John] does admit that the exhaust fan isn’t anything special and might need to be replaced more often than if he had gone with one that was corrosion-resistant, he’s decided that the cost of this maintenance doesn’t outweigh the cost of a specialized fan. He also notes it’s not fire- or bomb-proof, but nothing he’s doing is prone to thermal anomalies of that sort. For fume hoods of all sorts, we might also recommend adding some automation to them so they are used any time they’re needed.
Nice build.
But, what chemical processes does he undertake that need such an apparatus?
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Umm,
Needs: 3D printing, sanding, cleaning parts, painting, soldering, de-greasing, casting epoxies, metals, … caring about one’s health, caring about one’s family’s health, …
For pretty much any hobbyist who doesn’t just type on a keyboard all day.
You would be correct in assuming I know nothing about which process causes what and how much, if any damage. You don’t. Nobody does.
Most of us will become ill, and few will die of “natural causes”. When fate catches up, do you really want the opportunity to say “I wonder if if was because of …”
3D printer charcoal filters, and little DIY fume extractors made of Altoid cans just don’t cut it.
Don’t fool yourself. This cabinet my not be ideal for all the needs listed. If you really are a great maker/hacker, make something that fits your needs. Don’t be a lazy a&s. Look at it as another tool, one that has your back. Especially if you have kids (for their safety and their right to have healthy parents).
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I do wonder what we will see with those who work in close proximity to 3D printers with only typical building air handling/filtration systems in the future. As far as soldering, painting, de-greasing, etc, we have an entire generation of engineers who exposed themselves to lead and soldering fumes for many decades with an equal or greater median lifespan than adjacent generations, and as far as chemical exposure we have several generations of mechanics who seem to specialize in soaking(immersing? lol) themselves with all manner of solvent, oil, etc with similar results despite the higher alcohol and tobacco usage that seems to follow this group. The human body is clearly very good at filtering out toxins but as we move into 3D printing being commonplace in homes all over the place, I can’t help but wonder if it will be a different story. We are already aware of these “microplastics” that are being found in the environment (and human bodies) everywhere, and correct me if I’m wrong but didn’t we see a slight decrease in median lifespan over the past few years? These plastic compounds and the fumes they emit when melted are often much more complex than simple hydrocarbon solvents/oils, solder, etc. Maybe we will find our limits…
I think it’s quite telling how people get all bent out shape about printing ABS, but think PLA must be so much safer. Just because our senses don’t register something as nasty, doesn’t make it safe. There are enough poisons out there that we can’t taste or smell, but are proven damaging or deadly.
With what’s going on in the world, obviously something is causing brain damage …
Well, PLA is certainly much safer than ABS (although that doesn’t necessarily make it “safe”).
RE: “Jason says: … PLA is certainly much safer than ABS …”
Mmmhuh … “certainly much”, … sure.
Can’t tell from photos but if the vapors being worked with are legit toxic rather than annoying of noxious. If the former, be very careful with amateur fume hoods- fluid dynamics aren’t intuitive and most commercial ones are deceptive. They are laminar flow. A homemade box with a fan probably has a bunch of local turbulent zones and without testing carefully with some smoke, it might actually be pumping vapor out of the hood, as crazy as that sounds.
Source- chemist and biochemist that has worked under the hood for 25 yrs
Agreed! This build is for the latter (annoying / noxious fumes). I’d also have some concerns about pumping anything worse than that directly outside for my neighbors to enjoy.
This hood doesn’t have a set of baffles in the back for proper laminar flow, but even if it did, I would need to make the work area substantially less obstructed to get laminar flow to work properly. As it is, it keeps the enclosure more or less at negative pressure, and from what I can tell by hanging a piece of tissue paper around various spots at the entrance, the airflow is going into the gap under the sash with a reasonable velocity along the full width of the hood. I suppose this may be an advantage of having a relatively small fume hood and a relatively large fan!
I’ve noticed there are a number of commercial grade lab fume hoods that follow a similar design (small enclosure, no laminar flow baffles, exhaust port up top). They seem to be sufficient for common lighter duty tasks but are still well out of hobbyist price range. I’m any case, this setup seems to work much better than what I had before (open window with a box fan and some crossed fingers).
Rad to get a reply from the builder! Didn’t notice the sash in the photos haha. Only thing I do at home now is solder and I can see the smoke get sucked out with my eBay special fume sucker thing.
I’m definitely at the “safety police” end of the HaD commenter spectrum so thanks for looking out for your own safety and low level exposure.
Hey HaD, DIY electroless plating sounds far more interesting than “Man builds box with fan in it”, was this really the story you meant to publish?