Post-Processing Techniques
Finish your prints professionally with these techniques
Removing Supports
- Flush cutters
- Needle-nose pliers
- Craft knife / X-Acto
- Deburring tool
Technique:
1. Let print cool completely
2. Flex the part to loosen supports
3. Use pliers to grip and twist supports
4. Cut close to surface with flush cutters
5. Clean up remnants with knife
Tips:
- Tree supports often remove easier
- Support interface layers make cleaner breaks
- Some filaments release supports better than others
Sanding
- Start: 100-150 grit (remove layer lines)
- Medium: 220-320 grit (smooth surface)
- Fine: 400-600 grit (pre-paint prep)
- Polish: 800-2000 grit (glossy finish)
Wet sanding:
- Use water to prevent clogging
- Produces smoother results
- Works well for PLA, PETG, ABS
Warnings:
- PLA can melt from friction heat
- Wear a mask - plastic dust is harmful
- Don't sand TPU (gets gummy)
Filling & Priming
- Automotive spot putty
- Wood filler (for PLA)
- XTC-3D epoxy coating
- UV resin
Priming:
1. Clean part thoroughly
2. Apply filler primer (multiple light coats)
3. Sand between coats (400 grit)
4. Build up until smooth
Recommended products:
- Rust-Oleum Filler Primer
- Tamiya Surface Primer
- Montana Plastic Primer
Painting
- Spray paint - Easy, even coverage
- Acrylic craft paint - Fine detail work
- Airbrush - Professional results
Process:
1. Clean and dry the part
2. Prime the surface
3. Apply thin coats (2-3 color coats)
4. Let each coat dry completely
5. Clear coat for protection
Tips:
- Light coats prevent drips
- Hold can 8-12 inches away
- Paint in well-ventilated area
- Multiple thin coats > one thick coat
Chemical Smoothing
1. Create acetone vapor chamber
2. Place print in chamber briefly
3. Surface melts and flows smooth
4. Remove before over-smoothing
Warning: Acetone is flammable! Work in ventilation.
ABS juice:
- Dissolve ABS scraps in acetone
- Brush onto print surface
- Creates glossy, smoothed finish
PLA smoothing:
- Ethyl acetate or THF can work
- More hazardous than acetone
- Heat gun technique (careful!)
Assembly & Joining
- Super glue (CA) - Fast, strong, works on most plastics
- Epoxy - Strongest bond, gap-filling
- Plastic cement - Melts surfaces together (ABS)
- Hot glue - Quick but weaker
Mechanical joining:
- Heat-set threaded inserts
- Self-tapping screws
- Snap-fit designs
- Press-fit pins
Tips:
- Roughen surfaces before gluing
- Acetone welding for ABS
- Consider designing interlocking parts