Vat, Film and Build Plate Care

The vat and its film see liquid resin on every print. Wear gloves and eye protection for all of this work, as your resin's SDS says (the Formlabs Grey Resin SDS asks for chemical resistant gloves and safety glasses or goggles). Parts and terms are explained in Parts of a Resin Printer.

After every print

• Look at the film. Prusa says to check the bottom of the tank for damage before and after each print. If the film is damaged, replace it immediately; otherwise, Prusa warns, you risk a resin spill onto the parts underneath.
• Clear debris. Loose cured pieces from a failed print should not stay in the vat for the next one. See "Clearing cured debris" below.
• Clean the build plate. Prusa says to clean the platform thoroughly after every print: scrape and wipe the underside, clean it with IPA, dry it, and make sure it is shiny before the next print. Liquid resin left on it for a long time solidifies.

Resin in the vat: leave it or empty it

Prusa says to empty the resin tank after each print, pouring through a funnel, and not to mix used resin with unused resin. It also warns that resin left in a tank with the lid open can start to solidify, and that sunlight cures resin, so keep the printer away from windows. Other makers may allow resin to stay in a covered vat between prints; follow your printer's manual. Never leave a vat uncovered.

When you empty a vat, especially after a failed print, filter it. Prusa's spill procedure pours remaining resin through a filter into a bottle that fully blocks UV light. Formlabs says not to pour resin back into its cartridges, to avoid contaminating them, and to use a separate opaque container such as a wide-mouth HDPE or polypropylene bottle for storage. Label the container.

The film

• Replace it when it is scratched, dented, punctured or no longer clear enough to print well. A damaged film is a leak waiting to happen.
• Clean it the way your maker says. Prusa's rule for its SL1 and SL1S film is warm water with a little dish soap, and never isopropyl alcohol, alcohol or acetone. Other makers and other film types may differ; check your manual before you put any solvent on the film.
• No sharp tools on the film. Use a soft plastic scraper only where your maker allows.

Clearing cured debris

Some printers can do this for you. Prusa's tank cleaning routine cures one thin layer across the whole build area; loose solid bits settle onto it, and the layer is lifted out on a cleaning adapter and discarded. Prusa recommends running it before each print, sets its exposure from the resin's initial exposure time plus about 5 seconds for larger debris Maker spec, and says the adapter differs between the SL1 and SL1S. Large failed prints stuck to the film may need removing by hand.

On printers without a routine, wear gloves, empty or filter the resin, and lift out debris gently with the tool your printer maker supplies or recommends. Cured scraps go to the waste path in Resin Waste and Disposal. If the whole print stayed on the film, see Print Stuck to the Film.

The screen

Prusa says to keep the print display clean before starting a print, and to clean it with a damp cloth, LCD spray, or IPA or dish soap on soft paper towels. Do not use sandpaper, low-quality paper towels or sharp objects such as metal spatulas, knives or screwdrivers on it.

When resin spills

Prusa's spill procedure, condensed:

1. Turn the printer off and unplug it.
2. Pour the remaining resin through a filter into a UV-blocking bottle.
3. Clean the spill as soon as possible, before it hardens: soak up excess with paper towels, then wipe with IPA-dampened towels, except on delicate surfaces like the display or acrylic lid.
4. Check inside the printer for resin on the mechanism and sensors. If resin reached electronics or the light source, photograph it and contact the maker's support.
5. Inspect the film, which may have caused the spill.

Prusa says cured resin inside the printer that is not on moving parts or electronics is best left alone, because scraping can do more damage. For a spill outside the printer, Formlabs says to wash surfaces with soap and water. Resin-soaked towels are waste: see Resin Waste and Disposal.

Care schedule

When	Task
Before every print	Film undamaged and clean, no debris, screen clean, plate clean and shiny
After every print	Inspect film, clean build plate, cover or empty the vat per your manual
After a failed print	Clear debris, filter the resin
Film damaged	Replace before printing again; recalibrate if the maker says to

For the wider printer schedule, see Maintenance Schedule.