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.

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.

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.

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.

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.

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.

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!

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.

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

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!

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!

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 ;-)

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,

Extra note, I used a mix of sand and charcoal powder (raw) in a 2ltr bottle and had some horrifically bad alcohol go through it and come out okay. SO it might be a better idea to do 1 filter with a light packing of that around the filter to act as a kind of... pre-filter... filter :)

really like this video, keep up the great work man! it's cool to see someone share their passions with the internet

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

I think you are on to something with the two-stage filter, but I'd also recommend adding a "pre-filter" stage using a coffee filter or similar to take out the big chunks before it hits your 0.5 micron filter stack. For the clogging that occurs, you might be able to rig up a stirring mechanism or similar to keep the liquid moving. Not sure if it would help the clogging or not but might be worth a try with a cheap hobby motor and some 3D printed paddles. Just use a long shaft so the motor is well away from the alcohol.

I found the best thing was to use a UV torch to shine an intense spot on top of the liquid to polymerise the resin (if the UV goes through glass the resin sets on the glass and quite quickly blocks UV transmission). It also helps make the resin formed into tiny particles rather than mucousy sheets. It looks quite cool, almost a sort of roiling look where the UV spot hits it. Once done until there is no more movement, allow to settle, and then filter through filter paper. It's good enough for a first wash tank at this point. The settled gunk can be thrown away.

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!

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

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.

Would there be any value in running it through a simple sand filter first? Also maybe you could speed thing up a bit by creating a vacuum in the collection bucket.

I love watching your channel. The video on supports is required viewing in my 3d intro course for dentists. What an honor to get a prominent mention.

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

Love your vids. I can say however that using a purpose built alcohol distiller like you showed in the beginning of the video works REALLY well. I run mine outside and it goes through about 4L in about 40 mins with very little loss. The trick is to make sure the silicone seal makes good contact. I will say that it is pretty darn safe but you still want to do it outside.

I used a filter method with cotton wicking and activated carbon After a couple passes (replacing at least the cotton each pass) it went from gray cloudy to almost fully clear

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

Was looking for Nerdrotic and found this awesome channel, man amazing!

Another possibility: Make a simple solar still. Take your two bucket lids and run a wide tube/hose between them (sealed to the lids). Take one bucket with the dirty alcohol and wrap it in black plastic (or similar) and leave it in the sun. Take the other bucket and put it in the shade or - better yet - have it sitting in the ground (the bigger the temperature differential the better). It won't be fast, but over time you will accumulate distilled alcohol in the cooler bucket and the system will never heat up anywhere near combustion temperature so there's no fire risk. If the bucket lids seal well, there'll be no smell either. All you need to do is keep putting the dirty alcohol into the black bucket and emptying the clean alcohol from the cooler bucket.

Great video! I'm just getting started and this is great info to have - before I waste a bunch of IPA. Thank you.

I found this very interesting, good work.

Isopropyl is chemically different than ethanol. The isopropyl is very "branchy" like a tree branch which is a bit different than ethanol. This difference prevents the enzyme in our body from being able to metabolize. Methanol gets turned into formaldehyde in the body and that's what causes the most damage. But great video, You can also do something called "salting" out things that are dissolved in a liquid. I have had some decent luck with salting the alcohol first but I was running into issues of removing the salt without a distillation (I am also concerned with heating a very flammable solution.) These filters may be the answer so thank you for the advice.

I recently came across a video by Makers Mashup about using Aluminum Sulfate to remove resin particulate from solution. Maybe try using that as the first step then filtering after. Would be really interesting to see your thoughts on it.

I know this is from a year ago, but to help your system you just need multi-stage filtering. Make a stack of 4 or 6 buckets with increasingly fine filters as you go down. This should help prevent clogs as well. All that said, doing proper lab distillation with borosilicate glassware would probably cost 200 bucks up front in equipment and have almost no continual cost. You can let it sit in jars like you do now, then put it through a coffee filter and into a separatory funnel. The funnel will separate out a bit more of the solids over a few hours. Drain the resin off into a container, then drain the remaining alcohol into a round flat bottomed distillation flask. Put the flask on an electric hotplate with a magnetic stirrer and connect a distillation tube and a capture flask. Properly connected, this whole system is completely sealed and no vapor will escape. Control the hot plate temp so its around 82C, enough to boil the alcohol but not the water or resin. After running through the flask, you should have nearly pure alcohol.

That’s a really cool time travel suit, I hope to see more of it!

I tend to use 99.9 isopropynol and purify it be putting it out in the sun in a closed container for a while to cure. I have to shake them or take a silicone spatula to scrape the sides every so often depending on the size container I'm using. After a lot of it is cured out, I bring it inside and let it settle to the bottom for a while. I can then pour most of it off the top and then through a coffee filter. I deal with a lot of the "mucus" you described, but I managed to reclaim ~80% of my alcohol. I do a lot of printing across multiple machines and will clean my alcohol every couple days (so every 7-10 build plates full on a Photon Mono X) with pretty good results. I keep enough alcohol to have 2-3 batches rotating through being in use, settling, or curing in the sun at any given time. After seeing your results, I may have to look into how much I would gain from using a more extensive filtering process.

hmm.. since the issue is particulates, I'm wondering if a flocculant would be cheaper. A 5-pound container of pool flocculant is about the same price as your filters and can clarify 20,000 gallons of water. 10 grams of bentonite can clarify 5 gallons, and about 4 kg of bentonite can be had on Amazon for about $30. That's enough to do 2000 gallons and I know for certain it won't hurt the alcohol since it's used in wine making. I think the bigger benefit of flocculants is that you could clarify every container you have all at once. The down side is you'd almost certainly introduce a little water, at least with the bentonite.

I loved the history lesson, thank you! I love learning why things are the way they are when they don't make sense.

SUBED! Thanks for this, really useful and a good history lesson.

It seems to me that you couldn't simply run alcohol through filters and actually remove all, or most, the resin. Sure the particulates settle after a time, but their is still resin in suspension in the alcohol. The proof of that is that setting it in the sun will kick the alcohol and start the "sludging" process. Filtering after that, if there is still clear alcohol in the container, is then OK. This is what I have done many times. For proof this method works, I would like to see one more step tried: Put the completely filtered alcohol in the sun and see if it kicks and any of it turns to sludge. If it does not, I may trust this method. How about it, can you try this next step and see if there truly is any resin left in suspension in your final clear alcohol? Very Kurious in Kentucky.

What I typically do is I typically pour my used alcohol into disposable plastic bottles every couple prints, never letting it get that dirty. I set them on the window sill to settle and cure and then pour the alcohol through a coffee filter. Typically one 500ml bottle full of used alcohol will use one coffee filter before it's too clogged to be used quickly. It doesn't get the alcohol perfectly clean, but it does help a significant amount and doesn't take that long to filter.

Thank you for the awesome video this was very helpful info for this Noob Ive been resin printing for a few months now.

I've built the three bucket system with two filters each in the top two buckets. The issue I've come across is the plastic wing nuts were bad so the buckets would leak out into the lids beneath. I've replaced them with metal but even with the included rubber pieces there's still a leak from the buckets above onto the lids beneath them.

I like the idea of adding stages. I guess the nice thing about stacking a 3rd or more stage of filtration is that it really shouldn’t take much longer to do the whole batch. And if cheaper, more corse filters were used at the top it might make those at the bottom last longer.

The 'mucous' is a spongy suspension, if it is squeezed in a filter bag , the alcohol is released. I found this still had a lot of dissolved resin in it and required another exposure and filter pass. I tried a vacuum still instead of higher temperature boiling , but the phase change method is far too costly , unless it could be done this a solar still of some type. I'm also fine the smell of ipa offensive, worse than resin by far.

Good video, have you thought about adding air stones to the mix to keep the fluid moving, it might help stop the film settling on the filter so much.

Great video and tip. I am considering this technique.

Would love a follow up video on this after using it for a while! I'm sure dirty alcohol is far tougher on the filters than their intended use.

Rubbing alcohol was never drinkable, its isopropyl alcohol not ethyl so its not "denatured" at all. Its just inherently poisonous like methyl alcohol and its smell is also inherent in its nature, not an additive to make it non-drinkable. So your attempt to filter out the smell is bound to fail and the fact you thought it smelled "only slightly better" after filtration either was placebo effect or it absorbed moisture from the air and became less volatile because of that. It does not take Walter White to understand there are different alcohols that are inherently non-drinkable and smell different from one another. Also with proper distillation techniques you CAN separate out the ethanol (drinkable alcohol) from the adulterants that make it poisonous. Considering that nearly all fermentation leads to some methyl alcohol in the mix the distillation of fermented mash results in various "cuts" which based on the temperature of vaporization contain mostly methyl alcohol, mostly ethanol, and mostly water. The "heads" or "leads" being mostly methanol are discarded the tails at the end of the run mostly water are either discarded or added back into the main cut to lower its proof. Again Walter White need not be present, perhaps Popcorn Sutton (rest his soul) would be a better reference for the topic at hand.

A couple of tips, the grey residue that sinks to the bottom of the uncured dirty resin is just the pigment, not the photo monomer. Since the photo monomer is still liquid, it is also passing through the filter with the alcohol (unless the charcoal is doing something I'm not aware of, although your results suggest otherwise). The jelly like substance after you cured the alcohol is actually a resin/alcohol matrix; it's actually possible to mix it enough that the matrix gives up a bunch of the alcohol and becomes a pulp like substance, you can also squeeze out the pulp to release a bunch more alcohol. It should also be noted that simply filtering/straining the uncured alcohol doesn't solve any of the issues of dirty resin, since it doesn't remove the photo monomer which will still give your models that tacky feel. Any IPA recycling set up must include a way to remove the uncured monomers or the cured polymers and is why the best setups I've seen involve pumping the alcohol through clear tubing wrapped in UV LED tape and then filtering it through 10" whole house water filters.

Great video! Very helpful! Any chance you can produce a followup video with your triple bucket system? How much of a pain was it to clean the filter? At what point is the filter so gunked up you have to replace it? When you replace, what has to be done to the filter to prep it for safe disposal?

Maybe i am dense, but what i do with my alcohol is expose it to UV light and than filter it with paint filters. The resin is cured( clumped) and than the filter removes it. Simple, cheap, and seems to work. What am i missing here?

The "Baby Puke" stuff (at about 9:00 minutes in) might filter well if you first liquify the gel in a blender. This might break up the polymer matrix and make it so you can dilute the liquified slurry with a little more alcohol, then use Alum or some other flocculent to help precipitate out the cured resin.

Another fantastic video. As a micro business, I have to find ways to reduce costs and alcohol is very expensive. Will give this a try. Thanks!

have you tried out different filters since making this project? I'd be interest to see a comparison video if so

For something like this, you might want to try using a centrifuge to settle the resin at the bottom of a container, then draining the sediment from the bottom. Once the large particulates are removed, you could then optionally run the remainder through a filter

The filters are probably going to cost more than buying new batches of alcohol. Letting the alcohol sit and settle or accelerating using a coagulant would work. Maybe even try using centrifugal force.

Not the same thing, but back when I was at the University I used to work on a project where we filtered river sediment. Because the sediment is a mix of sand, mud and silt, using a fine mesh straight away would clog the filter and take forever, so we used different mesh sizes, starting on a 2mm mesh and going until a 0.5mm. I know resin particles are very small, a possible solution to the clogging would be using a larger mesh (or exposing the alcohol to UV for a few minutes, or both) so you remove the bigger particles first.

I'm wondering if you can make a centrifugal filter for liquids. If the resin is dense enough, maybe you could separate it cleanly for reuse. If not, including a UV source in front of the inlet might be enough to trigger the resin to cure and become easier to filter out with a centrifugal filter.

Great video. You could use a Peristaltic pump with a 3D printed float attached at the end of a silicone tube to transfer the dirty alcohol to the filter setup (prevents from disturbing the mixture with the settled resin bits).

For real though. Solid history lesson. Thanks for the info on prohibition.

This is a bless of a video. Excellent channel, excellent host!

I was inspired. I made this with 2 of these filters in 2 different 5 gallon buckets for a total of 4 filters going into a 3rd 5 gallon bucket. The alcohol comes out very clear. Haven't degunked the filters yet, so I'm really looking forward to that. It filters pretty slow, but it does work. However I don't consume huge amounts of alcohol with only one printer, so I'd say if you have lots of printers, you might want more than one setup to be filtering at any given time. It'll still make the money back easily.

This was a really informative video!

TY for your videos!

Great tutorial and thank you for the tip. Your right about it being VERY SLOOOOOOW.

I put my alcohol container on my magnetic mixer into my curing box and had it mixing during the curing time. It did not turn to mucus, but stayed granular. I ran it through a paint filter and it caught most of the cured material. Only did the one shot, will try it again, maybe even without the stirring to see if that helps.

I’ve been doing it for over a year with the distiller you had pictured and 70% ipa and it works fine. No problems or explosions so far. Do it outside and wear ppe. Saved a lot of money when there was a run a ipa for people making hand sanitizer.

Pressure will also increase the rate through the filter. Either deeper, or find a way to add pressure. Also, the catch bucket needs a vent so air can get out of the way to let more alcohol through the filter. Vent it into the upper bucket, ideally.

Great video. I'm glad KZfaq recommended it! I suggest you make some form of high flow bubbler. It helps keep my filters cleaner longer IMO, but likely adds to some evaporation loss. I just move one around the filter manually to help keep it clean, but be careful of disturbing sediment. Wanted a means to quickly agitate, but the bubbler was the only simple solution i had that didn't take up much space. Also, you need a pretty solid bottom and I suggest you mount the filter up from the floor of the container in relation to the amount of sediment you generally expect to have. Those flexible buckets make it easier to clean. Take apart, set in sun, once cured, flex the plastic to crack resin. I havent come up with a great solution for cleaning and storing the filters. Definitely waiting for it to settle and pouring off what you can helps. I started using a turkey baster to help with that collection process. I small UV blast under bottom helps clot the resin cake. I have also had some luck adding diluted bentonite clay to help get stuff to fall out of suspension and make a harder pack at the bottom. If you add a lot, it can be harder to cure though. I understand the desire to use glass, but getting those cakes out can be a pain. I tried a coffee over the filter with a big zip tie at base. Need to experiment more. I want a way to block anything .05 or bigger and let others through. The .03 clogs very quickly. I have a plan to add those to a third stage. I do not recommend for first stage - have them at second stage right now.

Don't know if it's been suggested but i think a vacuum filter would probably fix most issues right up, it would also be way faster. I've seen people use automotive pumps to save money.

Hi, I enjoy watching your informative videos. Why the long hiatus and do you plan on making any more in the future? :)

Thanks for the info. I'm trying my first filtering job. I allowed it to settle and then tried to leave most of the contaminates behind. Then, I put the alcohol in jugs and left them in the sun for ~16 hours. The plan is to pour what remains, through cheesecloth and see what I have. I hadn't thought of the method you mention and I'll be placing an order to Amazon shortly. :) BTW I'm visiting my local fire department because I'm considering using a distiller. So far, it will be at least 25 feet from any dwelling. It will be contained in either a steel worksite box or an order oven. Personally, I'm leaving towards the oven. That way, if there is combustion, it will be contained. Thanks again for the great info.

you could as a spout to the bottom bucket as well to be able to drain it once its full. that might make it easier and cleaner to transfer once its been filtered.

I'm an "armchair expert" at best so take what I say as food for thought rather than solutions that will work. It should be possible to use a centrifuge of some sort to dramatically speed up the precipitation of impurities. Also, to speed up filtering you could create lower pressure in the recipient bucket or create higher pressure in the source bucket to help push the liquid through. The problem with creating partial vacuum is that alcohol is already volatile, and with lower pressure it will evaporate even faster. I guess you could cool it down beforehand to mitigate it. If the dirty alcohol becomes a gelatinous mess when exposed to UV for a long time you might want to give it a small dose of UV, filter out whatever has cured and repeat the process as much as needed. Alternatively, the gelatinous goop could be wrapped in cloth and squeezed to separate the liquid from the resin. You might even try putting it into a blender or a centrifuge. The problem was that the resin cured while being intermixed with alcohol, so it formed something like a sponge with alcohol being trapped inside. By mechanically disturbing the structure it should be possible to release the liquid. Exposing dirty alcohol to UV after each use would probably prevent too much resin from building up in the solution. Granted, when there's not much resin dissolved in alcohol it's harder for it to cure, but it should work with enough UV exposure. Here's something I came up that I have no idea if it will work or not. Solubility of chemicals depends on the temperature. So, theoretically, if you put dirty alcohol in the freezer it might be cold enough to cause resin to separate. After all, alcohol freezes at very low temperatures, so a normal freezer should not be able to freeze it solid, but will (hopefully) chill it enough to cause precipitation. I'm actually really curious if this is a viable method. I think it should work better on very dirty alcohol as opposed to alcohol that was used to wash a part once or twice.

So how about centrifuging the dirty alcohol and decanting the clean alcohol from the top (maybe after exposing to UV to harden the centrifuged residue)? It might be possible to make a simple centrifuge from an old bicycle wheel (or old motor if you are suitably mechanically inclined). The main challenge would be ensuring that you balance the weight on either side of the wheel.

If it wasn't for your very helpful video, I would have tried all of that myself. Thanks!

I watch both your video and the one you linked to. Before I try this how did you clean off the filter itself once it gets gunned up?

Loved the video (like all of them) I have had some jars outside for months and what I do is just pour the clear stuff out into another container and then let it sit some more until more of it settles. What im really curious about is what do you do with the resin that turns into jello? I wouldnt think that just tossing it would be the way to go. what do you suggest?

I have had my best luck with indirect sunlight. Just like letting the larger particles settle, indirect light creates those larger particles that then fall out of the solution. This will leave me on the first 2 or 3 cleanings fairly clear alcohol. this does take a little time but can be done immediately. I am assuming the yellowing I get is the leftover color from the resins I use. It is imperfect and I use leftover milk jugs for settling then curing the waste resin/mucus. I hope this is usefull.

I'm using mostly Elegoo standard grey resin and found that cloudy grey IPA (after washing a few smaller models) will turn almost clear overnight with a thin layer of white uncured resin at the bottom of the container. I've placed this container in the sun for 2 days and the liquid turned milky white. There is more sediment at the bottom, but looks like there is no way back to (almost) clear IPA I had before the sun-curing :(

i use 3 glass containers with sealing lids. one has clean alcohol for final wash. the second is mostly clean for initial wash. the 3rd is the dirty stuff and is stuck in front of a uv light that cures the resin in the alcohol. once the resin is cured in the alcohol i use cheese clothe to filter the mucus out. cheese cloth is coarse but it can be used to squeeze out the majority of the alcohol from the goop. then i run through a coffee filter in a funnel. The alcohol that comes out of the coffee filter is usually clean enough to use for initial wash again. I just keep rotating the containers around and add new alcohol as needed.

Have you tried putting the jars in a centrifuge? There are simple, hand-cranked versions as well as electrical ones and I think that should work even if it's gotten all jellified.

What about a centrifuge? Like a filter it's mechanical separation of the clean alcohol from the resin bonded alcohol but you won't get clogging, it'll cost more upfront but you won't have the ongoing cost of replacing filters. Alternatively you could repurpose two pneumatic cylinders to vacuum boil the alcohol, you pour the dirty alcohol into a fully extended cylinder (only fill about a quarter of it) and attach it to a fully retracted cylinder, then seal it and pull down on the empty retracted cylinder. The pressure inside both cylinders drops, the alcohol cold boils, then you slowly retract the cylinder with the dirty alcohol (not too far or you'll inject it into the other cylinder) and as the pressure returns the alcohol vapor condenses and mostly ends up in the second (now fully extended) cylinder.

thank's for sharing !

Great video !!!

After seeing this video a few months back, I tried this out, but had issues with the filters not sitting solidly against the bottom of the bucket, and causing alcohol to spill. Tried finding metal nuts, and thicker gaskets so I could tighten it up a bit, but no luck.. kinda gave up after a while. But should probably give it another go, just because I have all the stuff.

Such a great video! Ich Love it 😍

As a former moonshiner I would not recommend distilling denatured alcohol. When you are distilling alcohol for drinking the strongest liquor going in the still is around 50% depending on how good your first distilling goes. At that point you still (pun intended) have a lot of water left and the alcohol content in the still decreases. Even if the denatured alhocol is dirty the alcohol content is still high and with no water to counteract combustion.

I wonder if some sort of agitation system, a fish tank fan or something like, would help keep the layer of resin film forming on the filter. Or at least reduce the time needing to be spent wiping the resin gunk off the filter. I've not been printing long enough to be here yet but am not far off.

thank for great experiment

Hello, would it help if you have something to constantly agitate the alcohol while filtering? like some kind of aquarium pump so it won't clog the ceramic filters. I was looking on some guides on how to 3d print and stubbled upon this video. Hope my comment helps and thank you for making this video!!

I'm wondering if a small air pump for an aquarium would be able to push the alcohol through a metal spin down filter to remove the larger chunks then stage down from there before running it through the last stage again. overall your filters would clog slower and the spin down filter is washable. not sure if the flow or pressure would be enough though.

It would be cool to put a rack near the top of the top bucket and pump alcohol from the bottom bucket to a sprayer in the top bucket. Just set your part on the rack, close the lid and let the sprayer hose down the part, then the alcohol filters back into the bottom bucket. This would prevent you from having to dirty another container. The sprayer may also help to prevent a bit of the buildup on the filter if it's positioned in such a way that it can hose it down a bit.

Would agitation help with the layer of resin on the ceramic filter. Something as simple as a crank attached to a wide paddle/agitator?

I've been looking at switching over from IPA to denatured and had a couple of questions. Is it as good as IPA and how are the fumes compared to IPA?

Could cellophane liners be used to help with container cleanup, or would that cause more problems?

I would be confortable in distillation, I did with an heating mantle and worked fine. In italy denaturated alchol has no methanol but it is still harsh smelling. Also distilled smells bad.

Last time i used some clean plastic box and i let it sit closed for about week on sun and the resin nicely catched to walls and alcohol stayed almost clean in middle. I was super happy because i was able to salvage about 4-5l of alcohol which looks mostly clean but i'll get to know that once i print something