Snapmaker Outlines Best Practices for 3D Printing Post-Processing and Safety

Snapmaker has published a detailed technical guide on 3D printing post-processing techniques, outlining standardised finishing workflows, material considerations, and essential safety protocols for FDM and resin additive manufacturing.

Key Post-Processing Techniques and Materials

Post-processing encompasses every step taken on a 3D print after it leaves the build plate, spanning mechanical cleanup, chemical finishing, thermal treatments, and aesthetic coatings. While raw prints frequently exhibit visible layer lines and support scars, systematically applying the correct post-processing method significantly improves aesthetic appeal, dimensional fit, and mechanical performance.

Mechanical Surface Preparation

Mechanical preparation forms the foundation of part finishing:

• Support Removal and Deburring: Using flush cutters and deburring tools allows precise trimming of support contact points and first-layer brims without damaging the primary part walls.
• Wet Sanding: Dry sanding thermoplastics generates friction heat that can melt the surface into a gummy texture. Wet sanding with water and a mild detergent cools the material and prevents clogging. Progressing from 220-grit up to 1000-grit or higher produces a smooth finish ready for priming.
• Composite Safety: Wet sanding is strictly required when working with carbon-fibre or glass-fibre reinforced filaments to suppress dangerous airborne particulate dust.

Chemical Smoothing and Thermal Treatments

Different materials react uniquely to solvents and heat during advanced post-processing:

• Vapour Smoothing: Acetone vapour smoothing remains the most reliable method for dissolving layer lines on ABS and ASA prints, yielding a glossy, injection-moulded finish. However, attempting to chemically smooth PLA or PETG using aggressive solvents like dichloromethane (DCM) poses severe chemical hazards and requires lab-grade fume hoods.
• Thermal Annealing: Baking printed parts near their glass transition temperature reorganises polymer chains into a semi-crystalline structure, substantially raising heat deflection temperatures (HDT) and mechanical strength. Slicer scaling must compensate for the typical 2% to 5% volumetric shrinkage that occurs during heating.
• Sealing and Painting: Applying automotive filler primers fills microscopic layer gaps before acrylic painting. For liquid-tight applications, brushing on a two-part epoxy resin seals surface porosity completely.

What This Means for South African Makers

For South African makers, small businesses, and print farms, understanding proper post-processing allows local workshops to produce professional-grade parts without investing in industrial production machinery. Most essential finishing supplies—including automotive filler primers, wet/dry sandpapers, nitrile gloves, and respirators—are widely available across local hardware and automotive supply stores.

Furthermore, keeping safety top of mind is critical in home workshops, garage setups, and educational makerspaces. Emphasising wet sanding for composites and avoiding dangerous chemical smoothing agents helps maintain safe working environments across South Africa’s growing maker community.

2>DC3D’s Take

Post-processing is often the dividing line between an unfinished prototype and a functional, commercial-grade part. However, the best way to streamline post-processing is to optimise your print settings before hitting start. Refining support overhang angles, using tree supports, and adjusting layer heights in slicers like Bambu Studio, PrusaSlicer, or Snapmaker Luban saves hours of tedious manual labour later.

When finishing is required, taking a methodical approach to safety and material compatibility prevents ruined parts and health risks. Proper personal protective equipment, disciplined wet sanding practices, and clear solvent boundaries are essential tools for any serious 3D printing workshop.