Can you sand PLA prints?
Yes, it is possible to sand PLA prints, but it requires the right technique and patience as PLA is a relatively brittle material compared to other 3D printing materials such as ABS or PETG. Sanding is often used to smooth out layer lines and improve the surface finish of PLA models, especially before painting or other finishing.
How to grind PLA in the best way
Choose the right sandpaper
Start with a coarse sandpaper (about 150-200 grit) to remove the most prominent layer lines. Then continue with finer grit sizes (400, 800 and up to 1000 grit) to get a smoother surface. Water-based wet sanding at 1000 grit or higher can give an extra smooth finish.
Use circular movements
To avoid obvious sanding marks, it is best to sand in circular motions rather than back and forth. This helps to smooth the surface more evenly and gives a better end result.
Be careful with heat
PLA softens at low temperatures (around 60°C), so prolonged sanding can create friction and heat that can deform the model. Avoid pressing too hard and take breaks when necessary.
Wet vs. dry grinding
- Dry grinding works well for initial rough grinding, but it can create a lot of dust.
- Wet grinding (with fine-grained sandpaper and a little water) reduces dust and gives a much smoother surface.
Finishing for best results
After sanding, you can apply primer or filler to fill in small irregularities. A primer spray works well before painting. If an extra smooth surface is desired, an epoxy coating or acetone-based finish can be used, although acetone does not dissolve PLA as effectively as ABS.
Do you want a faster method to get a smooth surface without much sanding? Then you can use our online calculator to optimize printing parameters and reduce layer lines already at the printing stage.