Electroplating and Metallising 3D Prints

Logan F.

Metal Finishes on Plastic Parts

Electroplating is the electrochemical deposition of a metal layer onto a conductive substrate. It is a manufacturing process used for everything from chrome bumper bars to gold jewellery. Applied to 3D printed parts, it produces objects with genuine metallic surfaces: real copper, nickel, or chrome over a lightweight plastic substrate. The result looks and feels like solid metal, it catches the light correctly, feels cold to the touch, and develops patina appropriately, all while remaining far lighter and dramatically cheaper to produce than machined metal.

This might sound like an industrial process requiring expensive equipment, but home electroplating of 3D prints is genuinely accessible with modest investment. The maker community has refined the process into a reliable sequence that produces stunning results with off the shelf materials. Australian makers have successfully electroplated figurines, jewellery style prints, mechanical components, and artistic sculptures.

Making Plastic Conductive

Electroplating requires an electrically conductive surface, plastic is inherently non-conductive. The solution: coat the print with a conductive paint or graphite spray before plating. Graphite based conductive paints (available from electronics suppliers in Australia) are the most accessible: apply 2–3 thin coats with a brush, allow each to dry completely, and the surface becomes sufficiently conductive for electroplating. Copper loaded conductive paints are more expensive but produce a better initial conductivity that reduces plating time and improves uniformity.

Surface preparation before the conductive coat matters enormously. The electroplated layer faithfully reproduces every surface detail of the substrate; it replicates scratches, layer lines, and surface defects in metal. Sand and prime the print thoroughly before applying conductive paint (see our finishing guide). PLA and PLA+ are the best substrate materials; their smooth post sanding surface accepts conductive paint cleanly. The smoother the substrate, the more impressive the final plated result.

The Electroplating Process

For copper plating: prepare a copper sulphate solution (available as "Blue Stone" from garden and pool supplies, it's a common fertiliser and pH adjuster). Use pure copper electrodes (available from electrical and plumbing suppliers). Connect the painted print to the negative terminal of a 3–6V DC power supply and the copper electrode to the positive terminal. Submerge both in the copper sulphate solution. Current flows, and copper ions migrate from the electrode and deposit onto the conductive print. Over 30–120 minutes, a genuine copper layer builds up. The thickness can be increased with longer plating time and higher current.

The resulting copper surface can be polished to a mirror shine, darkened with liver of sulphur for an antique patina, or left bright. Further plating processes (nickel over copper, then chrome over nickel) can produce chrome like finishes, though these require additional chemicals. The copper plated result alone is dramatic and widely applicable in architectural models, jewellery, artistic prints, and decorative objects all benefit from this treatment.