Dirty wash alcohol is the quiet running cost of resin printing, and the idea behind this project is simple: stop pouring it out. Nick Wilson built a wall-mounted station that keeps isopropyl alcohol fresh by curing dissolved resin into solid particulates and then straining those solids out of the liquid again.
The whole thing lives on a plywood panel. A red-and-black SEAFLO diaphragm pump pulls in the contaminated IPA and circulates 2 gallons twice per minute. From there the solvent travels a 10 foot loop wrapped in roughly 48 feet of 405 nm UV light, done with two 8-foot LED strips. After the coil it passes through two blue filter housings, first a 5 micron cartridge and then a 0.5 micron one, all linked with flexible clear vinyl tubing, and the clarified alcohol returns to the wash tank.
What stands out to me is the pairing of a very long light path with graded filtration. Sending every drop down 48 feet of UV before a fine polish seems like a thorough way to treat it, and the results back that up: the alcohol stayed clear even after 2.5 kg of prints had been washed in it.
One thing is still open. How long the cartridges hold up is not known yet, and whether the whole setup ends up saving money or just time is something only longer use will show.
Project by Nick Wilson. Watch it on their YouTube channel: