Resin Hollowing and Drain Hole Guide

Resin Hollowing and Drain Hole Guide

Hollowing saves resin but creates new risks: suction cups, trapped liquid resin, weak walls, and bad drainage. Drain holes must be placed for printing and for post-processing, not just hidden for looks.

What it usually looks like

• Hollow print splits or leaks later
• Print fails from suction forces
• Resin remains trapped inside model
• Drain holes are visible in bad locations
• Hollow model feels weak or deformed

Most likely causes

• Drain holes are too small or poorly placed
• Model creates a suction cup during lift cycles
• Wall thickness is too thin
• Internal supports are missing or weak
• Inside was not washed and cured properly

Step-by-step fix order

1. Check model orientation before placing drain holes
2. Place holes near low points for printing and cleaning
3. Use enough wall thickness for the part size
4. Add internal supports if the shell needs reinforcement
5. Wash inside hollow parts thoroughly
6. Cure inside through holes when possible

Settings and checks to record

Printer-specific notes

Large resin busts and statues need serious hollowing review. A model can look printable but still fail from suction forces.

Material-specific notes

Tough resin may handle hollow shells better than brittle resin, but no resin makes trapped liquid safe.

Prevention checklist

• Use hollowing software intentionally, not automatically
• Preview suction zones
• Keep drain holes accessible for flushing
• Never sell hollow prints with trapped resin risk

When to stop and use AI Doctor

If the same symptom comes back after these steps, collect the failure photo, slicer profile, printer model, filament brand/type, and exact settings changed. Then run it through the AI Print Doctor so the next fix path is based on your real symptoms instead of random setting guesses.

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