Here is how to clean resin prints: two baths of 95% or stronger isopropyl alcohol (IPA), dirty first and clean second, with 2 to 5 minutes of agitation; a soft toothbrush through every recess; a syringe through every drain hole; then a full dry until the surface looks dull. Only then does the part go under the cure lamp.
Water-washable resin swaps IPA for water and keeps every other step. Whatever is still liquid when the UV comes on cures where it sits, either as the white bloom Liqcreate traces to curing wet parts carrying a resin and IPA mixture, or as tack. Cure times and temperatures are in how to wash and cure resin prints.
What do you need to clean resin prints?
Two lidded containers, 95% or stronger IPA, nitrile gloves, a soft toothbrush, a syringe or squeeze bottle, paper towels and moving air from a blower or a can of compressed air. A few of those items come with a reason behind the spec:
- IPA grade. Siraya Tech asks for 95% or higher (its FAQ accepts 90%), and Elegoo’s getting-started guide gives the same 95%. Raise3D calls 70% rubbing alcohol less effective, slower and more prone to whitening.
- Brush. Soft bristles only; Siraya warns that hard brushes can scratch or distort the surface.
- Lids. IPA’s flash point is about 12 °C, below room temperature, so baths stay closed between parts and away from the printer’s power supply.
How to clean a resin print, step by step
- Drain and wipe. Raise the plate and let excess resin drip back into the vat, which is where Siraya Tech’s guide begins, then wipe the bulk off with paper towels. Resin that goes back in the vat never loads your IPA.
- Dirty bath, 2 to 3 minutes, moving. Elegoo specifies about 2 to 3 minutes in 95% IPA, Siraya allows 2 to 5, and Prusa’s CW1 defaults to 3. Swirl, dunk and turn the part; moving solvent reaches recesses a still soak misses.
- Supports. Decide whether to clip now (see below).
- Clean bath with the brush. In the second container, brush textures, engraved detail, the underside and every support contact. Hackaday’s advice is to rinse the brush and the part often so you are not scrubbing dissolved resin back in.
- Flush hollows. Raise3D recommends flushing internal channels with a syringe during washing so they do not cure shut. Push IPA in one drain hole until it runs clear from the other; liquid sealed inside a hollow is out of the cure lamp’s reach.
- Final rinse. A last dip or squeeze-bottle rinse in clean IPA lifts off the diluted resin the brush loosened.
- Dry until dull. Liqcreate gives at least 30 minutes in a ventilated spot, or 2 minutes of pressurized air; the part should look dry and dull. Elegoo warns that a part cured before it is completely dry may show white impurities.
Count every minute in solvent, re-washes included. Prusa does not recommend more than 10 minutes in IPA, warning that tiny cracks can appear more than 24 hours later, and Liqcreate says green (not yet post-cured) parts can crack after 20 minutes. Formlabs caps its High Temp Resin at 6 minutes total. For standard hobby resin, treat 10 minutes across both baths as the ceiling.
Supports: clip before or after cleaning?
Formlabs’ default is to post-cure before removing supports so features do not warp. The exception is dense support that blocks light from part surfaces, and that same density traps resin; Prusa’s CW1 guide names resin left under dense supports as a reason to re-wash. Rule of thumb: miniatures and thin panels keep supports through cleaning and cure, while a solid part on a dense forest gets clipped after the dirty bath so the brush reaches the underside. Better support placement shrinks the problem; see how to add supports to resin prints.
How do you know when the IPA is too dirty?
Replace a bath when it turns cloudy or, if you measure, when dissolved resin reaches about 10 to 12%, the replacement point Formlabs uses. Tack can start earlier, at roughly 5 to 10%, and Formlabs flags Draft, Tough 2000 V1 and Tough Resin V5 as prone to tack above 5%. Siraya Tech names dirty or reused IPA as the usual cause of cloudy, sticky surfaces.
The Form Wash’s hydrometer reads specific gravity from 0.716 to 0.881: calibrate it in fresh IPA, and replace the bath when the O-ring floats above the tall wings. A generic hydrometer works on the same principle if your baseline reading is taken in your own fresh IPA, since water content shifts the starting point.
Two habits stretch a bath. Formlabs says a preliminary rinse in a small volume of solvent significantly extends IPA life. And rotate: when the clean bath clouds, it becomes the dirty bath and the old one is retired. Retired IPA never goes down a drain; see how to dispose of 3D printer resin safely.
Before blaming a bottle of resin for tacky parts, run an elimination test. Print two copies of one small part, clean one through your current baths and one through fresh IPA with identical times, then dry and cure both the same way. If only the first stays tacky, the bath is the cause.
Can you use an ultrasonic cleaner on resin prints?
Yes, with water in the tank and the IPA in a closed container sitting in that water. Never pour IPA straight into a consumer ultrasonic tank. Omegasonics warns that tank heat can quickly push IPA into a dangerous vapor-rich condition, and Raise3D’s guide says to never fill the tank directly with flammable alcohol.
The indirect method Omegasonics describes: water in the tank as the coupling medium, just enough solvent to cover the part in a glass beaker or stainless container, loosely covered, in a ventilated room. Raise3D suggests 5 to 10 minutes at 30 to 50 °C, starting near 5 minutes at 30 °C; softening or stickiness afterwards means too much heat or time. Ultrasonic minutes count toward the 10 minute solvent ceiling.
What can you clean resin prints with instead of IPA?
Ethanol, TPM (tripropylene glycol monomethyl ether) or a dedicated resin cleaner on standard resin; water only on resin sold as water-washable. Siraya Tech lists acetone, paint thinner, alcohol with additives and strong degreasers as solvents to avoid. Each substitute changes the timing:
- TPM. Raise3D describes it as non-flammable and low-odor. Formlabs says to wash as with IPA, longer if needed, and notes its standard resins printed at 50 or 100 microns stay waxy after TPM until post-cured.
- Household degreasers. Raise3D calls Mean Green non-flammable but gives Simple Green only a reduced flammability risk; both are slower, often needing ultrasonic help and an alcohol rinse. Siraya’s avoid list includes strong degreasers, so try one on a scrap part first.
- Water-washable resin. Follow the bottle. Siraya Tech’s Simple resin, for example, wants a 15% alcohol-in-water mix, no soak longer than 30 seconds, 4 to 6 short cycles totaling 2 to 3 minutes and an immediate blow-dry. The wider trade-off is in water-washable vs standard resin.
How do you fix a resin print that is still sticky or cloudy?
Re-wash it. Hackaday’s author found that sending a sticky part back to the UV box never gave a satisfactory result; the fix that works is clean IPA, a soft toothbrush on the problem areas, a final clean rinse, a full dry, and more brushing if it is still tacky. Then match symptom to cause:
| Symptom | Likely cause | Fix |
|---|---|---|
| Tacky everywhere | Saturated or reused bath | Fresh IPA, brush, rinse, dry; if already cured, re-cure 5 to 10 min |
| Tacky in recesses, textures or under supports | Resin held by geometry | Brush in the clean bath, syringe-flush, clip dense supports |
| White bloom | Cured while wet with IPA and resin | Before cure: re-wash, dry until dull. After cure: brush in fresh IPA; what remains is cured in |
| Fine cracks a day or more later | Too long in solvent | Keep total IPA time under 10 min |
| Soft or warped fine detail | Overwashing | Stay inside the 2 to 5 min window |
The re-cure time is from Raise3D, the crack timing from Prusa, and Siraya Tech links soft or warped detail to overwashing. A part that came off the plate soft or splitting has a printing problem, not a cleaning one: see resin print layer separation causes and exposure calibration.
How to verify a resin print is clean
Run these checks before the part goes under UV:
- Dull, not glossy. Liqcreate’s criterion is a part that looks dry and dull. Gloss in a recess is liquid resin.
- No tack. A gloved fingertip on a flat face and in the deepest recess comes away clean. If not, Siraya Tech’s instruction is to wash and dry again.
- No solvent. No IPA smell, and nothing wet blows out of the drain holes under air.
- After cure. Uniform color, no white bloom, no tack. Bloom points at the drying step; tack points at the bath or a missed recess.
FAQ
can you clean resin prints with 70% isopropyl alcohol
You can, but it is the weakest option. Raise3D says 70% alcohol is less effective, needs longer agitation and raises the risk of whitening, while Siraya Tech and Elegoo both call for 95% or higher. That longer agitation also eats into the 10 minute IPA ceiling Prusa recommends, so buy the stronger grade.
can you leave resin prints in ipa overnight
No. Overnight is far beyond the limits vendors publish. Prusa advises against more than 10 minutes in IPA and Liqcreate says green parts can break or crack after 20 minutes in solvent. A forgotten part can look fine when you pull it out; Prusa warns that tiny cracks may appear more than 24 hours later.
can you clean resin prints with water
Only if the resin is sold as water-washable. Standard resin needs IPA, ethanol, TPM or a dedicated resin cleaner, and Raise3D notes plain water is not effective for standard resins even in an ultrasonic tank. Water-washable parts still need a full dry before curing, because Siraya Tech links incomplete drying to white marks.
do you need a wash station to clean resin prints
No. Two lidded jars, a soft toothbrush and 95% or stronger IPA do the same job by hand. A wash station adds powered agitation and a timer, which makes batches repeatable, but it does not replace the clean second bath, brushing the recesses, or flushing drain holes with a syringe.
