Tried so many methods over the last 3 years, best way I have found is let the dirty IPA settle for a week in the dark, 90% of your gunk will settle out and when you filter it you are not filtering the gunk and it passes thru the coffee filters SO much easier. Most of the time I wont even filter it as its settled so much its almost clear again., it does mean you ideally need to have 2 batches of IPA so one can settle while you are using the other. A good alternative to coffee filters is several layers of extra fine cooks cheese cloth, the benefit of these is you can squeeze the sludge to get more of the IPA out and they are reusable, I use at least 4 layers, but due to the size of these cloths thats usually only 2 of them folded in half.

A few things that works for me. First I do not clean the supports as it just gets your IPA dirty faster. Second I use 2 baths of IPA prior to the wash and cure station, you will have just one really dirty IPA to clean often and the other ones can be used over a longer period of time. Third, to clean the dirty IPA, I expose it to UV over a long period of time in a closed container (a bottle is fine), then I filter it through a kitchen towel, why? because the coffee filters are too thin and gets clogged so fast... The advantage of the towel is that, when all the liquid goes through, it leaves this gewy slimy residue that you can squeeze to get as much IPA as possible out. It leaves a solid cured plastic on the towel. Let it dry and you can remove it in one bloc so the towel can be reused again. Then you can filter it with the coffee filter, it will be way way faster :)

I have a dip pot of IPA that I put the models in straight off the build plate. This gets off the majority. I then put them through the wash and cure. Once first dip IPA is no good I get rid and replace it with IPA from the wash & Cure. Gives me loads more time before I need to filter the wash & cure IPA.

Great video, thanks! I tried cleaning my IPA tank along the same lines the other day, it didn't go very well as I didn't think about the resin curing as I was doing it - now I've actually watched your video I'll give it another go. Coffee filters and big funnels - top tips 😁

Great idea, I'll try this method. Thanks

The method I'm currently using starts with waiting for the resin to settle to the bottom of the dirty alcohol container (as I'm sure almost all of us). Then I don't decant or pour thru filter, but just use one of those electric water pumps (the ones designed for the large water bottles). These pumps are really cheap (5~7 euro in my area) and work perfectly fine with a single push of a button, so no jerking the dirty (settled) container, and risking to have to wait for it to settle again. Of course some alcohol is left at the bottom with the most of the resin, which you can't extract w/o sucking also lots of resin, so that alcohol I do pour thru a paper coffee filter, which is very slow, but I already have most of the alcohol clean(er) so I can print & clean more parts. The main problem with this method is the long waiting for the resin to settle. I think this forced most of us to rotate at least two batches of alcohol - a cleaner one for the current printing'n'cleaning, and a dirty one waiting to settle. But I researched a bit, and discovered relatively simple method that doesn't take any additional consumables or leave much dirty alcohol and is fast and forces the resin-alcohol separation to happen several thousands times faster :) Centrifuge! Specifically a oil-filtering centrifuge. There are some on the market but they're way too expensive (and often over-engineered for our needs). So the downside is you'll have to assemble it yourself. I've seen most people do it by welding some steel parts, but I (and I guess many of you) don't have any experience with welding. So I found that there's a two-epoxy glue for metal that has incredible strength JB-weld (and I think there are alternative brands too). So the device is quite simple really - have only few details to do properly. You have a spinning cylinder. It has roughly the shape of a cooking pot, but with additional ridge on the top edge that narrows a bit the top opening. The you have to drill few holes at the bottom - one in the dead center to mount the rotation rod, and few drain holes near the center. And that's the main part :) The other part is a housing - it has to be larger and taller than the spinning cylinder preferably with a lid to stop alcohol sprays. It's convenient to be cylindrical too, but it's not moving so it doesn't matter what shape it is, it just have to allow free rotation of the spinning cylinder inside it. The only trick about the housing is that its bottom is separated in 3 areas - like concentric circles: - the outer most is for the clean alcohol that has been accelerated by the spinning cylinder to the walls of the housing and will drip to the housing's bottom; - the middle one is for the dirty fluid left at the end. When you turn off the centrifuge it'll flow to the bottom of the spinning container and thru the few holes near its center and thus to the middle area of the housing; - the center area of the housing is just a hole for the spinning rod to come thru; these areas are separated by a circular ridge to prevent the fluid flowing between different areas and mixing again (or pouring out of the housing). The last parts are a strong stand for the housing and an electric motor at the bottom with its rotating rod upwards connected to the spinning cylinder (passing thru the housing). Some people use convenient power tool as the motor. The important thing about the spinning cylinder and the motor is that they need to be perfectly balanced - minimizing vibrations will allow much higher RPMs! The way it works is that you turn it on, and the inner cylinder starts spinning fast. Then you pour in it slowly the dirty fluid to be separated. Because of the centrifugal forces it'll be immediately accelerated to the wall of the spinning cylinder. At higher RPMs the fluid will be like a vertical wall of liquid around the inner wall of the spinning cylinder. When you keep pouring in more alcohol (or whatever fluid you want to clear) it'll eventually reach the ridge at the top edge of the spinning cylinder and then it'll start flowing over it, and the fluid going over the ridge won't have anything to stop it, so it'll be accelerated to the walls of the housing (that's why it has to be somewhat bigger and taller than the spinning cylinder). Cleared fluid will leak on the walls of the housing and will reach the outer area on the bottom of the housing, and then thru the drain hole(s) in it will flow to the container for the clean fluid. The heavier particles (ie the resin) will be kept firmly against the wall of the spinning cylinder. When you pour in all the dirty fluid you have, you can stop the centrifuge, so that the dirty fluid trapped between the bottom and the ridge of the spinning cylinder will flow down to its bottom and will flow thru its drain holes, and right down into the middle area of the housing, and thru its drain hole(s) into a separate dirty fluid container. Now you can keep that dirty fluid for later processing, or pass it thru coffee filters (or just let it evaporate and leave only the resin if you'd like). NOTE: you can use a heavy fluid or material to displace the last amount of alcohol. This type of centrifuges is most often used to filter oil, and for it you can use water as oil and water don't mix. However water & alcohol react and make hydrogen bond, which the centrifuge can't break, so don't use water with the alcohol. Also some people put few strips of kitchen paper on the inner wall of the spinning cylinder, which will trap most of the resin and will make cleaning the centrifuge much easier.

i've seen designs for a double funnel that can be printed off. it allows for more flow so the Resin tainted IPA doesn't bottleneck at the.. well at the bottleneck of the funnel. as the funnel fills up, it begins to flow out through another layer and continues into the container you are pouring into. I haven't done this yet, i just got my printer today and am in the middle of doing test prints

I use two tubs of metho. i dunk and slosh around in my first dirty tub to get 90% of the resin off the print. then when the print looks clean i put in the wash and cure to give a second clean. i havent refilled my tubs in 6 months the my first pass tub is very dirty but all the resin eventually sinks to the bottom.

i use Diggers Mineral Spirits $4/litre from Bunnings to clean my prints, works just as well and it's less sticky than IPA too i found

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 :(

Thank you for the great tip!

You shouldn’t use (or suggest) a water distiller for for flammable liquids, it’s not designed for it and has potential to cause a fire or explosion

I have resin on the bottom of my alcohol container, what's the best way to remove it?

Great video, where did you buy the big bottle of IPA from?

I would always let it settle in the sun or cure station for a long time before doing the coffee filter method, cheese cloth the clot out, and then distiller !

i tried this and my entire bottles content turned into a jello lol maybe recovered 50 mls of ipa out of 1 gal

I’m here after I left my IPA under a UV light for 3 days. All sludge

How I clean my IPA. I vacuum it.