Can We Recycle 3D Printing Alcohol?

I've done both distilling and filtering. They are both a pain. Distilling is faster but is a fire hazard. Odor is worse for distilling as well. I broke the thermal sensor on two different distillers before the first gallon. Both methods are messy as well.

Tall thin containers are good for letting the particulates and heavier liquid resin settle to the bottom quickly. Once the resin has settled to the bottom of the container (leave it for 24 hours or longer) expose it to UV light and then carefully decant the clean alcohol off the top. It'll look like you're leaving a lot behind (and you are) but the amount you salvage is worth it once you consider the time spent.

Such a fantastic video. I have buckets of IPA sitting in my closet for a few months now. For sure should try this. Also refuse to use a distiller. Seems like a massive fire Hazzard.

I enjoy your videos. A bit of background info on myself: I currently work for BASF. Prior to that I was a Combat Engineer. So, chemicals and explosives is kind of my calling (so to speak). A 3 stage filtration system would be a little more efficient for removing IPA/DenAl from your resin slurry. An additive for encapsulation or covalent bond would help pull the larger resin particles out. Something like charcoal would be the most cost effective route. Also, AGITATION in the 1st stage would be a MUST. I would steer clear of a bubbler/fluidizer, unless you plan on using an inert gas like nitrogen or argon, etc. Adding atmospheric air adds oxygen. And if you know anything about the "Fire Triangle", you DO NOT want to add O-2 to something that is already flammable. Slow, mechanical agitation would be the best bet. However, that costs more $ for that equipment. Unless you have kids at home who need a new chore. Now, as far as distilling goes: I've been using a distiller for 2+ years now. The very same that you spoke of in the beginning of this video. The particular model that I have is programmable. It is a feature that is absolutely necessary for nothing other than safety's sake for those who are looking into distilling their cleaning solvent with one of these machines. Both basic models and ones that are programmable state that they have an "Auto Shut-off Feature" that will turn the heating element off once the distiller is empty. DO NOT RELY on this feature. It's basically the same type of sensor that detects thermal runaway on an FDM printer. While autoignition of alcohol is 750F, I'm not willing to tempt it. At the least, a timer is ESSENTIAL. 45m to an hour for 4L is enough to distill the majority and still leave a liquid slurry in the bottom the the vessel. Put it into a bucket, leave the lid off and let the sun vaporize the rest. Another reason to not use the auto shut-off feature is because the machine will basically cook the remaining resin and you'll end up having to scrape a terrible smelling, rock hard resin pizza crust out of the bottom of the machine. I always use the distiller outside or just inside my garage with the door open and a fan blowing the fumes out. Not necessarily due to fire hazards, but because the fumes are TERRIBLE. I can absolutely understand your concern with using a distiller. I did a lot of reading on different ones and their feature before I decided to go this route. The 2 main factors that helped my decision was that 1. the model that I bought is a closed system (during the heating process all the way until the condensate drain) and 2. it is programmable and has a timer. A bit of knowledge and common sense go a looong way. Having a background in chemicals also helps. But then again, there are people out there who still believe that the world is flat.

As a retired kitchen worker, let me sing the praises of the humble 5-gallon pickle bucket. The weight of the plastic is such that it is frequently used to construct armor for reenactment sorts. The lids have a gasket and clamping system that will last for many, many re-uses.

Thanks for testing this. Side note denatured alcohol and isopropyl alcohol are two different molecules. The term rubbing alcohol can refer to either. Denatured alcohol is ethyl alcohol that is poisoned, usually with methanol. Thought I would point that out since you use all the above terms interchangeably and I got confused.

You really need to let the resin set first, then pour out that relatively clean part, let it set again, pour out, expose it to the sun to let the rest of the resin to polymerize, then you can filter it relatively easily. Tried it, it works, amount of waiting time is painful though.

I love that you really dedicated a year between this video and your most recent!!! Seriously keep it up and so looking forward to the next one!

This is an awesome path forward for both saving some money and reusing material. Thanks!

I almost always use a spray of solvent to clean parts rather than a dunk. A spray bottle works fine but my Iwata paint gun is even better. It is bigger than an airbrush but smaller than a regular paint sprayer. Does an excellent job of spraying solvents. Paper towels sop up the alcohol. The waste is minimal and clean up is easy and simple.

I played around a bit with UV polymerisation during my PhD and early research career so have a bit of background in this (as well being a chemical engineer for over 20 years with lots of varying experience across a number of industries!). I think if you stir the alcohol/resin mixture whilst exposing it to UV it will more likely form smaller discrete particles rather than snotty gloop. Continuous stirring should allow the alcohol and polymerised resin to separate regardless and more resin to polymerise by continually turning over the jar's contents to expose all of it to UV. You could use a paint stirrer on a pillar drill to agitate or a lab magnetic stirrer or as someone suggested, aquarium air stones. Note air stones might also lift the polymer out of solution by the processes of flocculation/flotation if done right (Possibly as a separate step - you can push air through your ceramic filter in reverse to achieve this - also a great way to backflush your filter). Stirring up your filter bucket will also reduce the gelling on the filter and speed up the filtration. Reducing the amount of UV light the mixture is exposed to at any one time will likely reduce the reaction rate of the polymerisation which may or may not help avoid the snotting depending on the type of polymer. Good luck!

Bravo sir! Thank you for sharing your ideas & projects! I'm new to resin printing & I've already went thru 3 gallons of the stinky stuff in less than 2 months! So I'm definitely going to try this! Keep doing what you're doing & thanks again!

Thanks for this! Will be trying this out in the future for sure.

For the 3 bucket system, you could fill the top bucket with loose activated charcoal as the first pass filter, then double up the ceramic filters for the second stage

As somebody who reprocesses alcohol by putting it under the same UV cure light I use for my resin parts and then filtering it through what you described as a paint filter, it's impressive seeing how this high level of filtration is able to get you perfectly clear looking alcohol. Curing out disolved or suspended resin and using the 'paint filter' to catch that solid material still leaves my alcohol with an increasingly strong color to it as it continues to be reprocessed, and that's been a bit of a disappointment. I think what's happening for me is that resin has pigmentation particles suspended in the mixture of polymers and photoreactive molecules. As the polymers interlock within the standard resin mixture, they 'capture' the pigmentation particles within a cage of interlocked polymer bonds. However, once resin and alcohol is mixed, the carefully engineered molecular mixture gets totally dispersed in the alcohol. It does seem photoreactive components are still able to promote some bonding between polymers even when they're all interspersed in a sea of alcohol, but this bonding definitely isn't 'caging' the pigments anymore. The pigmentation particles themselves don't react to the UV light at all (which they shouldn't) and are too small to be captured by the 'paint filter', so my own reprocessing workflow just doesn't have any effect on them. What you're really up against trying to get that perfectly clear looking alcohol is getting a fine enough particulate filtration that you are able to filter out the pigmentation particles especially, although there may be some color cast to other magical ingredients in the resin mixture that might promote bonding/stability/etc but, like the pigments, fail to get compeletly captured in the polymer bonds when everything is super interspersed in alcohol. Honestly wouldn't have thought of it if I didn't see this video, though. Thanks!

Your channel is getting traction and the success by now that you deserve. Your are still one of the coolest guys in this maker department… Thanks a lot ;-)

Just found your channel, looks like your projects are right up my alley! Subscribed

I think you have a great idea about the double filtration. The only thing I think will help would be to have a filter that only gets the big stuff at the top, something like a fuel filter would probably work better. Then the ceramic filter would get the little stuff,

You need to do fractional distillation, the same process used in the petroleum industry to separate kerosine from gasoline. It uses differential cooling rates via a fraction column to pull off different precipitates based on their boiling points.

The graphics and animations that you use to explain the process are absolutely beautiful