Team Liqcreate would like to thank Kerry Stevenson and Fabbaloo for writing about non-toxic resin cleaning solutions.. The article has not been modified and the original article by Fabbaloo can be found here.
Cleaning 3D printer resin is often a messy task, and one that’s made more difficult with dangerous cleaners. Are there alternatives?
It turns out there are.
But first, if you’re not familiar with the concept of resin cleaning, let me explain. This is a process that must take place on every SLA/DLP/LCD 3D print. Those processes use liquid photopolymer resin. Photopolymer resin is designed to solidify when exposed to a particular form of energy. Typically this is 420nm wavelengths of light, delivered by laser or LED panels. The process allows for the 3D printing of extremely high resolution models.
Many different types of photopolymer resin have been produced that provide different effects. For example, you can use resin that 3D prints completely transparent, or resin that can withstand high temperatures when solidified.
Cleaning Resin 3D Prints
But all of them have one issue: they stick to the sides of the fresh print when the job completes. The print has been repeatedly dipped into a vat of the photopolymer resin, and when done it’s usually dripping wet. Oh, it’s an easy solution: just wipe it off.
But no, it’s not that easy at all. It turns out that the photopolymer resin is typically toxic and should not be inhaled or especially touched. This is nitrile glove territory, folks. You must remove ALL of the stray liquid resin. That’s because the print will undergo a final curing stage, typically being left in a UV-light bath for a time, or even left on a windowsill in the sunlight. Any stray resin will dutifully solidify and thus create blobs and solid drips on your print. It’s very important to remove every drop of liquid resin.
The usual method of resin cleaning is through IPA, or isopropyl alcohol. This solvent is easily obtained anywhere, and does a very good job dissolving resin drops. The drops remain in suspension in the IPA, which eventually turn it from a clear liquid to an ugly, discolored and highly toxic fluid after many prints have passed through. Cleaning works especially well if the IPA is actively circulated, a feature usually found in resin cleaning station equipment.
There’s a couple of problems, however. IPA is not exactly a safe material, although it is commonly available. It is flammable, and cannot be taken internally. It has a tendency to open up pores of the skin if exposed, and this allows faster entry of dissolved toxic resin if you’re working with “dirty” IPA.
I don’t know about you, but I am not comfortable with the notion of keeping a large vat of flammable fluid sitting in my workshop. It’s also become more challenging to source IPA these days, given its frequent use as a disinfectant during the pandemic.
Is there an alternative? It turns out there are several.
Some say acetone is a usable cleaner, but it’s probably even more dangerous to handle than IPA, so let’s discard that option.
Here are some other possibilities:
Liqcreate’s Resin Cleaner
“Liqcreate Resin Cleaner is an excellent, effective non-toxic post-print cleaning solution for 3D printing. It is a safe, highly effective cleans faster than other cleaner liquids based on IPA, bio-ethanol and other chemicals. Liqcreate Resin Cleaner is not a dangerous good, non-flammable and has no unpleasant odor.” This is available for €12.39 (US$15) per kg, or €60 (US$71) for 5kg.
Bradley Systems’ Yellow Magic 7
“Our Yellow Magic 7 cleaner was formulated as a flexo UV ink and varnish cleaner for printing human and pet food packaging. For some time now, we’ve been hearing from customers who have found it works well for another application: cleaning parts on SLA 3D printers.” Evidently Bradley Systems created this product for other industrial purposes, but then learned it was being used by 3D printer operators. They’ve since provided some advice on how best to use it for that purpose. Yellow Magic 7 is currently sold out these days but appears to be priced at under US$30 for a one gallon jug (3.8L).
Hero Wash 3D Print Cleaner
“HERO Wash is an excellent alternative to Isopropyl Alcohol IPA. HERO WASH Effectively Removes uncured Photopolymer Resin from your 3D Resin Prints. HERO WASH is a great general UV cleaner for in and around your workspace as well.” Hero Wash is available for US$15 for 1L, or US$65 for 5L.
In addition to these 3D print specialized cleaners, it is also possible to use various household general cleaning solutions. Some that are typically used by 3D printer operators include Simple Green or Mr. Clean. These are widely available at low prices, but results may vary as they were not designed for this purpose.
Finally, it’s also possible to mix combinations of these materials together. There are many reports of experiments with IPA being mixed with other solvents, usually in an attempt to reduce the overall cost of cleaning. However, results may have differing levels of quality and some chemicals should not be mixed with each other. Please be extremely careful if doing such experiments.
Selecting a cleaning solution for your resin 3D printing needs depends on a number of factors, including your workshop environment, budget, safety tolerance and print quality needs. There seems to be many choices for any situation.