Once the printed part has been removed from the build platform, washed in isopropyl alcohol, and is no longer sticky or wet, proceed with these steps to finish each print.
- Nitrile or latex gloves
- Flush cutters
- Sandpaper of varying grits
- Microfiber cloth
- Mineral oil
1. Post-cure the part
Some resins require exposure to additional UV light to reach their optimal material properties. For example, post-curing makes Tough Resin stronger, allows for proper burnout of Castable Resin, and ensures the biocompatible requirements for Dental SG Resin. Post-curing utilizes a heated, UV-lit chamber to complete the print process. Complete the post-cure before removing the supports; the supports prevent parts from warping during the UV curing process. If supports block sections or surfaces of the part in the cure chamber, consider an additional post-cure phase after removing supports.
Post-curing is optional for most use cases for Formlabs Standard Resins, which include Clear, White, Grey, and Black. Learn more about which resins require post-curing and the specific, recommended settings.
2. Remove supports
Use the flush cutters included in the Finish Kit to remove the support touch points one by one. Start on the outside edges to loosen the support scaffolding. Printed parts with fine detail or thin sections may require delicate support removal techniques. For the majority of parts, using the flush cutter to remove the supports at the touchpoint will guarantee the best results.
For the best surface finish and to avoid divots on the part surface, individually remove each support. Note that some supports may detach from the printed part during the alcohol bath or when other supports are clipped away. Divots and surface imperfections can be sanded away. In the case of imperfections, consider adding liquid resin to the surface, curing with an external light source, and hand sanding to smooth the part surface.
WARNING:Some methods of support removal may enable small pieces of supports to break away. Beware of flying debris and consider wearing eye protection and gloves to protect the skin and eyes.
Tips for Delicate Prints
Be careful when finishing delicate parts, in order to not break off any small features in your model. Small files and tweezers can also help for highly detailed parts. Follow these steps to handle and remove the supports from your delicate part:
- Break the base into sections only if doing so will not break your part during the process. This step is especially useful for multiple delicate parts in one print. Take care; separating the base can cause supports to snap away from the part and leave cracks or divots in some parts.
- Snip and break individual supports off of the base, as well as the touchpoint, in order to carefully access supports at the center of the part. Align the flush cutters closely to part surfaces to save time when sanding.
- Only peel supports by hand if the surface finish and integrity of delicate features are not important.
3. Sand to smooth surfaces
Removing support touchpoints will leave raised marks and divots dotting a part’s surface. Wear gloves to protect skin from resin dust that develops during sanding. Begin with the lowest/roughest grit sandpaper - 150, for example - and sand the part surfaces as desired. Gradually move toward the finest grit sandpaper, to achieve a flat, polished, and even surface. Consider using a sequence of 150, 220, 400, 800, 1000, and 2000 grit sandpapers, depending on the available paper options and desired finish.
WARNING:When choosing to sand, follow general safety precautions for sanding plastics. Consider using wet sanding to reduce dust accumulation and exposure.
4. Finish with oil
Sanding may leave a layer or film of dust on the surface of the printed part. Remove cured resin dust by wiping the part with a microfiber cloth and a small amount of mineral oil.
Mineral oil leaves a dull shine and damp feeling on the part surface, though too much oil may make the part feel oily to the touch. For a finer, more polished surface, return to the sanding step and wet sand with finer sandpaper grits. Novus Polish 3-step system can also aid in achieving a smooth surface finish.
Optional: priming, painting, and polishing
After removing supports, sanding, and polishing with mineral oil, the part is now complete. Learn more about going beyond the printed part in these Formlabs posts:
- Formlabs Support: Priming Prints
- Formlabs Support: Painting Prints
- Formlabs Support: Polishing Clear Resin for a Transparent Finish
- Formlabs Blog: The Ultimate Guide to Painting 3D Printed Parts
- Formlabs Blog: Printing Lenses on the Form 1+
- Formlabs Blog: Creating Camera Lenses with Stereolithography
- Formlabs Blog: How to Make a 3D Printed Prism