Activated Carbon for laser filter

ChrisD (+):

FYI - I bought a small container of activated carbon from an aquarium
supply store yesterday and left it near the laser. I think Paul also
made a web purchase of a larger bag of the same stuff.

I'm thinking we can get some Home Depot metal ducting and some filter
paper to fab a blow-through, in-duct activated carbon filter for the
exhaust of the laser cutter. The idea is that the noxious vapors from
the cut acrylic "adsorb" onto
the surface of the activated carbon in the filter media. I'm curious
to see how well it really works.

Missed seeing you last night to talk about it all, and plans when we
install a more powerful fan and new duct run.


There is some black netting in the dirty room that we may be able to use instead of filter paper. I’m thinking filter paper may not allow enough airflow and/or would rip under the pressure from the blower. The activated carbon should work well to remove odor.
Adafruit uses a rather large canister filter. It has a pre-filter that is just a cottony-pad (not sure exactly what) that catches large particles and a foam dust collector. They clean out every week or two (they say after about 40 hours of lasering). After that there is about 15-20lbs of activated carbon. They replace that every 6-12 months (remember, they cut a /lot/ more than us). And finally outside of that there is a hepa filter. We may be able to make this system ourselves fairly cheaply. Hepa filters on ebay are $10-80 and activated carbon isn’t terribly expensive. However, I’m not sure how much the dust pads are. Could probably use a shopvac filter for that.

Just my two cents!


Good post! Hopefully others are following this thread and somehow
this necessary improvement will get done. I'm thinking we should also
use some Home Depot metal ducting to avoid the flex hose fire hazard.
Deciding on the fan(s) and duct run are key too. If the activated
carbon works really well then we can just vent back into the HIVE (the
acid test)?