3DPrintCalcs
Post-Processing Time Calculator — Finishing Estimates
Estimate time needed for sanding, painting and finishing printed parts.
Filler primer before painting
Apply spray/brush colour coats after priming
How We Calculate This
Time Estimates
- Support removal = User-estimated time based on complexity
- Sanding = (Surface area / Sanding speed) x Number of passes (Sanding speed defaults to 50 cm²/min, adjustable in Advanced Options)
- Priming = (Surface area / Priming speed) + 1 minute setup (Priming speed defaults to 100 cm²/min, adjustable in Advanced Options)
- Painting = ((Surface area / 50 cm²) + 2 min setup) x Coats — this assumes a fixed ~50 cm²/min spray rate per colour coat
- Drying time = (Dry time x 1 if priming) + (Dry time x Paint coats) — one primer cure plus one cure per paint coat
Active time is hands-on work. Total time includes drying periods where you can do other tasks. These are estimates for hand-finishing; airbrush painting may be faster for large surfaces. Most spray primers and paints flash off in 15-30 minutes between thin coats; always follow the manufacturer's instructions before the next coat.
Frequently Asked Questions
Sanding time depends on surface area and desired finish. A small part (100 cm²) takes about 5-10 minutes per grit pass. Start with 120-grit and work up to 400-grit or finer. Each pass takes roughly the same time.
Yes, primer is strongly recommended. It fills small layer lines, provides a uniform base colour, and helps paint adhere. Use a filler primer (like automotive grey primer) for the best results on 3D prints.
Two to three thin coats give the best results. Thin coats dry faster, are less likely to drip, and produce a smoother finish than one thick coat. Allow proper drying time between coats.
For quick results: remove supports, do a single pass with 220-grit sandpaper on visible surfaces, spray with filler primer, then one coat of spray paint. Total active time is about 15-20 minutes for a small part.
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Last updated: February 2026
All calculations are estimates. Always verify settings with test prints before committing to final prints.