Precision Vapor Smoothing
Services
Transform opaque machined plastics into optically clear masterpieces, and seal 3D printed parts to achieve injection-molded surface quality. Experience flawless, glossy finishes with zero manual abrasions.
What is Vapor Smoothing?
Vapor smoothing (or chemical vapor polishing) exposes plastic components to a highly controlled chemical solvent vapor. The vapor interacts with the surface, briefly melting the outermost micro-layer of plastic. As it cures, the surface reflows into a perfectly smooth, glossy, and sealed finish—reaching deep into internal channels where manual polishing cannot.
Optical Clarity
Instantly turns frosted, CNC machined clear plastics (like Polycarbonate and Acrylic) into glass-like transparent components, perfect for lenses and light guides.
Internal Feature Reach
Unlike mechanical buffing, chemical vapor easily penetrates complex internal geometries, deep pockets, and complex manifolds to smooth hard-to-reach areas.
Water/Air-Tight Sealing
Melts the porous outer layer of 3D printed parts (SLS/MJF/FDM), sealing the surface to make it completely liquid- and gas-tight for fluidics applications.
Improved Part Strength
By smoothing out microscopic layer lines and machining grooves, vapor polishing reduces stress concentrations (notch effect), improving overall tensile strength.
Material Compatibility
Vapor smoothing is highly material-specific. We use tailored solvents and precise environmental controls depending on whether your part is CNC machined or 3D printed.
For CNC Machined Parts
Primarily used to remove milling marks and restore complete optical transparency to clear plastics.
- Polycarbonate (PC) Exceptional results. Achieves glass-like clarity. Ideal for light pipes and fluid manifolds.
- Acrylic (PMMA) Highly effective for polishing complex optical lenses and display covers.
- Ultem (PEI) Restores translucency to this amber, high-temperature aerospace/medical polymer.
- ABS Produces a very high-gloss, injection-molded appearance.
For 3D Printed Parts
Used to eliminate the rough, porous layer lines of SLS, MJF, or FDM parts, making them smooth, glossy, and washable.
- Nylon (PA12 / PA11) Seals the porous surface of SLS/MJF prints, improving aesthetics, elongation, and making parts fluid-tight.
- TPU (Flexible) Creates a smooth, rubber-like feel while maintaining the material's elasticity and sealing the surface.
- ABS / ASA (FDM) Completely melts away FDM layer lines, resulting in a perfectly smooth, structural component.
Design & Tolerance Considerations
Vapor smoothing is a chemical melting process. Understanding how it affects your part's geometry is critical for precision assemblies.
Dimensional Stability
Because vapor smoothing melts the surface and lets it reflow, it has a slight impact on the part's overall dimensions, although far less than mechanical sanding.
- Material Reflow: Overall dimensions typically change by less than ±0.05mm.
- Edge Rounding: Sharp 90-degree CNC edges will become radiused. If sharp edges are critical, vapor smoothing may not be suitable.
- Fine Features: Extremely fine embossed text or micro-textures may be softened or washed out by the vapor.
Stress Cracking (Crazing)
Chemical solvents can induce micro-cracking (crazing) in plastics if they contain high internal stress from the machining or molding process.
- Annealing Required: For CNC machined Polycarbonate or Acrylic, we strictly perform thermal annealing before vapor polishing to relieve internal stress and prevent crazing.
- Internal Threads: Solvents can pool in small blind threads. We recommend tapping threads after the vapor smoothing process if possible.
Vapor Smoothing FAQs
Common questions regarding our chemical vapor polishing processes.
Is vapor smoothing safe for medical or food-grade applications?
Yes. While chemical solvents are used during the process, they evaporate entirely during the final curing and degassing phase. The resulting parts leave no toxic residue and are perfectly safe, with the added benefit that the sealed surface prevents bacterial growth.
Can vapor smoothing make my Polycarbonate part 100% optically clear?
Yes! Machined Polycarbonate naturally looks frosted or translucent due to tool marks. Vapor smoothing melts these micro-scratches, restoring the part to glass-like optical clarity, making it perfect for light pipes, lenses, and sight glasses.
How does it affect the lead time?
Vapor smoothing is a highly efficient batch process. It typically only adds 1 to 2 business days to your CNC machining or 3D printing order, depending on whether pre-annealing or complex masking is required.
Quote Machining & Vapor Smoothing
Get a turnkey manufacturing solution. Upload your 3D CAD files today, and specify "Vapor Polishing" for your clear plastics or 3D printed parts.