How to Electroplate Resin 3D Prints with DIY Graphite Paint for Shiny Metal Finishes

Summary:

This video demonstrates how to electroplate resin 3D prints using a homemade conductive graphite paint to achieve shiny metal finishes in copper, nickel, gold, and silver.

Print resin parts with a high-resolution printer (like Elegoo Mars 4 9K) for minimal layer lines, which are crucial for a smooth final finish.
Create a DIY conductive graphite paint using acetone, binder (two-component adhesive binder works), and micro graphite powder.
Prepare the prints by removing rough edges and sanding, then apply multiple coats of the DIY graphite paint, polishing between coats to achieve good conductivity (aim for around 1k Ohm).
Set up a copper electroplating bath with acidic bright copper electrolyte and copper anodes (filtered to prevent contamination). Use a rotary jig for even deposition.
Calculate the required current based on the print's surface area (using tools like Blender's 3D Print Toolbox). Run the copper plating process (e.g., 4 hours at 1-2A/dm²).
Perform intermediate polishing on the copper-plated parts to smooth the surface further before applying subsequent metal layers.
Apply additional platings like nickel, gold (using stainless steel anodes), and silver (using silver anodes), noting the toxicity of these electrolytes and the importance of PPE and proper ventilation.
Showcase the final results of the plated 3D prints. Collect and dispose of chemical waste responsibly.

Finished gold plated brooch and copper plated pendant [ 00:11:42 ]

Introduction [00:00]

The video explores applying shiny metal coatings (copper, gold, and silver) to resin 3D prints through electroplating.

The process aims to create realistic metal props or objects.
Key highlights include a DIY conductive graphite paint, electroplating techniques with minimal issues, and achieving a good polish without extensive grinding.

Creating the 3D Prints [00:30]

Resin prints are used for electroplating due to their smooth surface finish.

A resin printer with a 9K display minimizes visible layer lines, which is important as electroplating magnifies surface imperfections.
While FDM prints can be used, they require significant post-processing to smooth out layer lines.
Prints featured: a flying lady figurine (interpretation of a famous design), a Melina's brooch from Elden Ring, a Mora coin from Genshin Impact, and a pendant from Creative Britt.

Various 3D resin prints before plating [ 00:09:07 ]

Creating a DIY Conductive Paint for Airbrushing [01:19]

A DIY conductive paint is made using graphite powder, which is globally accessible.

Ingredients:
- Mixing container
- Micrographite (4 micrometer, 99% pure graphite) [01:29]
- Solvent: Acetone or butyl acetate [01:34]
- Binder: Binder from a two-component adhesive was found to work well, but other binders may suffice. [01:40]
Mixing Process:
- Dissolve approximately 1g of binder in 40g of acetone.
- Add 5g of graphite powder and mix thoroughly.
- Transfer the paint into small dropper bottles for airbrushing. [02:50]
Safety Precautions:
- Emphasize the importance of personal protective equipment (PPE) like a respirator, eye protection, and gloves due to chemical fumes. [01:50]
- Work in a well-ventilated area. [02:12]
  
  Ingredients for DIY graphite paint: graphite powder, solvent, and binder [ 00:01:25 ]
  
  Mixing the DIY graphite paint [ 00:02:45 ]

Making 3D Prints Conductive [03:15]

Proper surface preparation and application of conductive paint are critical for successful electroplating.

Surface Preparation:
- Resin prints need to be smooth and even.
- Remove rough edges and use sanding fleece. [03:05]
- Electroforming/electroplating amplifies small scratches, so a well-prepared surface is crucial.
- A rotary tumbler with walnut granules (0.4-0.8mm grain size) can also be used for polishing. [03:42]
Applying Conductive Paint:
- Apply at least 5 coats of the graphite paint. [03:21]
- Allow each layer to dry thoroughly.
- Polish the print with a cloth in between layers to improve conductivity. [03:26]
Checking Conductivity:
- Use a multimeter to check resistance.
- Aim for a resistance of around 1000 - 2000 ohms (measured with thumb's width apart). [04:05]
  
  Applying graphite paint to a 3D print [ 00:03:24 ]
  
  Measuring conductivity of a coated print with a multimeter [ 00:04:09 ]

Electroplating Copper on Graphite Paint [04:15]

Copper electroplating is the first step, forming the base layer.

Bath Setup:
- Use acidic bright copper electrolyte in a container. [04:15]
- Use one or two copper sheets as anodes. [04:23]
- Filter the electrolyte and place anodes in coffee filters/fleece bags to prevent contamination from suspended particles. [04:42]
Electric Field Management:
- An even coating requires managing the electric field distribution, which is geometry-dependent, especially in copper plating. [05:07]
- Moving the part is beneficial. A rotary jig with a continuous servo and controller can be used for this purpose. [05:16]
  
  Components of a rotary jig for electroplating [ 00:05:19 ]
Power Supply and Current Calculation:
- An adjustable power supply capable of constant current (C.C.) is needed. [05:43]
- Limit the current and increase voltage, then adjust current to the calculated value until the C.C. indicator lights up. [05:53]
- Connect anodes to the positive pole and the print (cathode) to the negative pole. [06:04]
- Calculate the required current (typically 1-2 amps per square decimeter) based on the print's surface area. [06:12]
- Blender's 3D Print Toolbox add-on can calculate the surface area. [06:24]
  
  Blender software calculating surface area of a 3D model [ 00:06:28 ]
Plating Process and Results:
- The first piece after 4 hours of copper plating shows a smooth surface with few impurities. [06:44]
- Rinsing and filtering the electrolyte is recommended between batches. [06:51]
- Issues arise from insufficient preparation (e.g., conductivity), leading to blotchy plating or field artifacts. [07:05]
  
  A copper plated 3D print pendant emerging from the bath [ 00:06:48 ]
  
  A poorly copper plated 3D print due to insufficient conductivity [ 00:07:18 ]
- A successfully plated part measured 150µm thickness after 4 hours at 1.5A/dm². [08:36]
  
  Measuring the thickness of the copper plating with a caliper [ 00:08:38 ]

Intermediate Polishing 3D Prints [07:55]

Polishing the copper layer is done before applying final metal finishes.

All copper-plated pieces are polished to prepare them for the next plating steps. [07:56]
A rough sanding is sufficient if using a polishing machine. [08:00]
Polishing by hand takes longer. [08:08]
Cautionary note: a part was damaged during machine polishing. [08:25]

Polishing a copper plated coin on a polishing wheel [ 00:08:13 ]

More Platings: Nickel, Gold and Silver Electrolyte [09:09]

Applying subsequent layers of other metals.

Nickel Plating:
- Uses nickel electrolyte and nickel anodes. [09:10]
- Nickel electrolyte is toxic.
- The Flying Lady receives a nickel coating (5 minutes at ~2V). [09:50]
  
  Nickel plating setup with the Flying Lady print in the bath [ 00:09:52 ]
Gold Plating:
- Uses gold electrolyte and stainless steel anodes. [09:15]
- Gold electrolyte can produce very toxic fumes, especially with acid contact. All acids are kept away from the workspace. [10:28]
- The brooch, coin, and pendant are plated with gold. [10:38]
- Brush plating with a different gold electrolyte is an alternative to bath plating. [10:51]
  
  Gold plated pendant after emerging from the bath [ 00:10:42 ]
Silver Plating:
- Uses silver electrolyte and silver anodes. [10:54]
- Silver electrolyte can stain skin black for weeks.
- Silver is applied over the gold layer (the nickel layer can theoretically be skipped). [10:59]
- The pendant receives a silver plating as the final layer. [11:02]
  
  Silver plated pendant [ 00:11:02 ]
Waste Disposal: All chemical waste (liquids, dried paper) must be collected and taken to a recycling center due to toxicity. [10:10]

Results [11:05]

Presentation of the finished plated pieces.

The successfully plated 3D prints are showcased, including before and after comparisons.

Gold plated Elden Ring brooch next to the resin print version [ 00:11:07 ]

Silver plated Flying Lady figurine [ 00:11:22 ]

Gold plated Genshin Impact Mora coin [ 00:11:37 ]
Further tutorials and relevant information are available in the video description. [11:21]