Why do resin prints need post-curing?

Resin prints come off the printer only partially cured. Post-curing with UV light completes the polymerisation, increasing strength by 50-100%, improving heat resistance, and eliminating the tacky surface. It also makes the part food-safer.

Can I over-cure resin prints?

Yes, excessive UV exposure can make resin prints brittle and cause yellowing (especially with clear resins). Standard resins typically need 3-10 minutes. If the surface becomes chalky or the part cracks easily, it is over-cured.

Does water curing help?

Yes, curing submerged in water prevents oxygen from inhibiting the surface cure. This eliminates the tacky surface finish and gives a harder, more uniform cure. Place the part in a clear container of water under the UV light.

Can I use sunlight instead of a UV station?

Yes, but results are inconsistent due to weather, time of day, and season. Place the print in direct sunlight, rotating every few minutes. Allow 2-3x the time compared to a dedicated curing station. UV stations give more reliable results.

3DPrintCalcs

UV Curing Calculator — Post-Cure Time & Settings

Calculate post-cure time based on UV wavelength, power and part thickness.

Part Thickness

Thickest dimension

Resin Type

UV Source

UV Wavelength

How We Calculate This

UV Curing Calculations

Cure time = Base time x Thickness factor x Source factor x Wavelength factor
Thickness factor = sqrt(Part thickness / 10mm)
Rotations = Based on total cure time for even exposure

UV light at 405nm is optimal for most resins. Thicker parts need more time as the UV must penetrate deeper. Rotating the part ensures all surfaces receive even exposure for uniform curing.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.