Can I clean my resin 3D prints without isopropyl alcohol (IPA)? If you are like me then you’ve noticed that the coronavirus (COVID-19) pandemic has caused a massive shortage of IPA. Finding an alternatives to IPA right now is difficult, and priced extraordinarily high if you do. Looking at a price point of more than $40 per liter and having not stocked up ahead of time I decided to take a look of some of the alternative cleaning options on the market.
What Alternatives to Isopropyl Alcohol (IPA) Can I Use to Clean My Resin Prints?
My new ultrasonic cleaner nestled in between my box of supplies and my Anycubic Photon
Isopropyl alcohol is the obvious answer, but when it is in short supply what are my alternatives. Methylated spirits (denatured alcohol) should work, this is ethanol mixed with a percentage of methanol to prevent it from being potable. Methylated spirits should be available in most hardware stores. My local hardware store was sadly out of stock when I went searching.
If you use a water washable resin then supposedly you can just use water. With water washable resin scrubbing or significant agitation are required. As I’m printing with a 50/50 mix of Elegoo Rapid Grey and Siraya Blu this also was not an option for me. I have seen multiple references on Youtube and Reddit about multipurpose cleaners. Specifically degreasers are supposed to work well if you use them in an ultrasonic cleaner.
I selected Mean Green as my cleaner to test and I purchased an inexpensive ultrasonic cleaner. The ultrasonic cleaner should work even if I need to use IPA or methylated spirits so I don’t feel this is a wasted purchase.
Shopping List
How Do I Use an Ultrasonic Cleaner for 3D Print Post Processing?
Filled with Mean Green and ready to go
The ultrasonic cleaner I purchased allows for both temperature control and a set time for cleaning. Fill up the reservoir with your cleaner of choice. If using heat set the temperature and wait for it to equilibrate. Place your resin covered 3D print in the basket and submerge in the solution, set the time, and turn it on.
You should see agitation in the liquid as it cleans. Once the timer has stopped remove the basket and inspect your prints. Rinse with water and see if there is any uncured resin remaining.
WARNING: If you are using a flammable material for cleaning such as alcohol you should NEVER fill the ultrasonic cleaner directly with it. Instead you should fill the cleaner with water. Then use a sealed plastic bag with your print in the alcohol in that. Alcohol will quickly aerosolize in the ultrasonic cleaner and that close to electronics it is not a safe combination. I also do not recommend using the temperature control. Alcohol is flammable, please do not create an unsafe situation.
How Well Does Mean Green Clean Resin?
Fresh off the printer
My first attempt at cleaning my prints was to print out some Star Wars minis I had designed with my 50/50 mixture of Siraya Blu and Elegoo Rapid Grey resin. Of course I used my trusty Anycubic Photon. After I removed them from the build plate I cleaned them in room temperature Mean Green in the ultrasonic cleaner for 5 minutes. Things looked pretty good so I washed them with warm water while removing the supports.
Room temperature, 5 min cycle time
Looking pretty good so far, the resin did take on a little of the green coloration from the bath
I placed the prints in a glass jar and covered them with room temperature water. 5 minutes in my UV box and they are ready for inspection. Inspection showed glossy areas of the print where there had been a layer of uncured resin clinging to the surface. This is specifically noticeable in crevices and fine detail. I’m calling this test a failure.
Curing in my UV chamber submerged in water
Cleaning attempt 1, glossy areas are caused by uncured resin left on the model
The second attempt at cleaning my prints, I repeated the exact same files with the exact same resin. This time I preheated the Mean Green in the ultrasonic cleaner to 50C. I again cleaned the minis for 5 minutes. Everything was still warm from the cleaning so I just snipped the supports right away. I put them back in for another 5 minute cycle to clean off any remaining resin.
5 min @ 50C, looks like a radioactive hot tub
After their second bath I rinsed them in water to clean off the Mean Green. I again cured them submerged in clean water for 5 minutes.This time there are no glossy areas, even in the very detailed crevices of the characters faces or the grooves in the bases. Success!
Perfect! No glossy areas. However the resin is slightly discolored from the Mean Green.
Summary
It turns out that IPA is not necessary to clean a resin 3D print if you have the right equipment. This is a huge help to me as I was looking at a long pause from resin printing until I could secure IPA. I don’t know yet how many build plates I can do in a single batch of Mean Green before it needs to be changed out.
After the ultrasonic cleaner settled it did appear that the resin sank to the bottom of the vat. I suspect I can treat the Mean Green the same way I did IPA and expose it to UV to cure the suspended resin then filter it through a coffee filter to remove the particles. If you try this method we would love to hear about your experiences in the comments below.
Super helpful. Thank you for sharing your progress.
Hey ResinIsLife,
Thanks for reading, so glad you found it helpful. If you give it a try we’d love to hear about your mileage as well.
Thanks for the report. Just wanted to confirm something…. After the first failure, you changed two variables, i.e., you doubled the amount of ultrasonic time from a single 5-minute bath to two 5-minute baths, and you also increased the bath temperature from ~22 C to 50 C.
Have you tried experimenting whether it was the temperature increase that did the trick, or was it the second bath that fixed it?
Asking because I was thinking of getting a cheap ultrasonic watch cleaner and using it with Mean Green. It does not have a warming function. But if your process only works with 50 C heat, then I’ll have to find a different ultrasonic cleaner.
Thanks for any info.
Hey Scott,
I did not break out the two variables as this was less of a controlled study and more of a “Oh no, I have 1 bottle of IPA left and can’t get it” kind of necessity. I haven’t gone back and experimented as I have a working process with my cleaner and am happy with it. Perhaps I should at a later date just for the sake of completeness.
A quick look at reddit community shows a number of people claiming to use it at room temperature some don’t even use an ultrasonic and scrub them with a soft brush. I personally don’t want to be scrubbing my delicate prints pre curing as damaging a print means a complete redo and a lot of my models have fine bits that would break off.
Resin tends to become far more fluid when warm so it should remove easier in a heated cleaner. You might need to increase the duration of the wash and maybe use a soft tooth brush to get into little tiny crevices without the heat. Different resins will respond differently as well. I use a mix of Siraya Blu and Elegoo grey and while the Elegoo is pretty normal, Siraya has a reputation for becoming thick and unworkable when the temperature drops too much. That was really what spurred me to use heat in the first place.
If you end up going with a room temperature cleaning I’d love to hear how that worked out and if you needed to do anything differently.
Thanks for reading, I hope you found the post helpful!
Keiran – quick questions about disposal/clean up…how did you clean out the basin of the ultrasonic cleaner and what did you do with the resin tainted mean green liquid?
Excellent article – I’ve been trying to find a good cleaning process and I’ve been switching between testing out mean green, purple power, 99% IPA, and 90% IPA.
Hey Twizzly Wizzle,
For the resin tainted solution I do the same thing as I used to with IPA. I hit it with a UV light for 10+ minutes to cure all the loose resin then I run it through a coffee filter in a funnel. Likely a few coffee filters as they’ll clog up. All the fine particulate accumulates there and you can just toss it as it’s been cured. I then let the liquid evaporate off or you can bottle it up and dispose of it depending on your local laws.
Hope you have luck looking at alternate cleaning methods, for non-IPA based cleaners it seems the agitation is very important so if you are trying to replace the old IPA dip and shake method you might not get far. You could try a fine bristled tooth brush and sit and scrub them if you aren’t wanting an ultrasonic.
Hi thanks for showing this
I tried the UK equivalent of Mean Green (Flash Cleaner) It might work in an ultrasonic cleaner at 50degrees C but it definitely does not work in an Anycubic wash and cure station as it leaves an oily residue.
Looks like we are stuck with IPA…yuck
Hey Dave,
Sorry to hear that Flash Cleaner in the Anycubic wash and cure station isn’t working. The ultrasonic does a much better job of breaking up the resin into smaller particles that can be carried off in the solution. IPA dissolved resin better than these degreasers so it needs less oomph to clean off the print. You could try denatured alcohol (methylated spirits I think it’s labeled in the UK) which is basically very high proof ethanol with methanol or other poisonous components added to prevent people from drinking it and getting around liquor taxes. Ethanol should dissolve resin similar to IPA and might be a good cheaper substitute for IPA. I have a can of it that I got from the hardware store in the pain section which I use in my alcohol burner that I use to tip new arrows. Best of luck and thanks for reporting in!
I used Simple Green Extreme in a strong ~11:1 dilution, since I had some for general purpose cleaning. I can probably use a milder blend.
My ultrasonic was set to 35C and 3 minutes.
Using the Photon’s test print (the lattice cube), cleaning results were excellent. It looks like the uncured resin fully dissolved.
It does require a second cleaning step to wash off the Simple Green, but it’s water soluble, so a simple rinse helped there.
My post cure procedure was flawed though due to inexperience and caused some problems that I plan to address ln my next run.
Hi Josh,
We appreciate you sharing your results here and glad it’s working for you as well. I also do a rinse with water after the ultrasonic to clean off the solution and then if I’m not curing the part submerged in water I let it fully dry before curing. For really delicate parts I might do a final rinse in IPA if there is a lot of really fine detail work that needs additional cleaning but that’s fairly uncommon except in prints where the part itself is cupping around itself and holding the resin inside a small pocket. A soft bristled toothbrush can also help in those situations.
What issues did you have with your cure process? Are you using a purchased station, made your own like I did, or just using the sun?
I’m very new to resin printing, this having been my first print on the printer, and I built my own curing setup by using a germicidal UV discharge lamp.
Turns out those don’t have a strong 405nm line, so it wasn’t very effective at all at actually curing the resin.
I ended up leaving it in the sun the next day after realizing that I didn’t actually post-cure it.
For my next run I’ll use a display turntable and a 405nm UV LED light bar that came with some UV cure screen protectors for my cell phone.
The idea of wet curing (having the print submerged in water) never crossed my mind, I didn’t think that the UV light would have meaningful penetration through the water to reach the print.
I might try that on another run, or if the print doesn’t sit well on the turntable by itself.
Thanks for the reply!
Yeah all UV is not the same. Germicidal is UV-C which isn’t what most resin cures at. The UV glue from your screen protector would be in the same range as the resin so good call there. Lots of LED strips or lamps at that range available as well so if you find you don’t like the form factor of that one (maybe it doesn’t fit larger prints well or something) then there are some cheap alternatives to go for.
The idea behind curing the print submerged is that the curing reaction can be inhibited by oxygen. Water will have less dissolved oxygen in contact with the print than air will so the curing reaction is more efficient. I’m honestly not sure if this explanation is completely correct but anecdotally I have noticed for my prints that when I cure then submerged in water they do seem to cure faster. There is also the benefit that you don’t need to wait for the print to fully dry, which you will need to do otherwise as you’ll get some cloudy spots on the print if parts of it are wet when curing.
Best of luck in the hobby and thanks for reading.