Step 2: Paint Active Area

Working with Carbon Grease

Carbon grease is a material that quickly contaminates the whole workspace including clothes and shoes. Always wear gloves as soon as carbon grease is applied to the membrane and use a disposable underlay. If you value the clothing you are wearing, immediately change a glove if it becomes dirty in order to avoid any further contamination.

Before painting, put some of the carbon grease from the tube into a plastic cup for easier handling.

Painting the active area

  • Attach the stencil for the active area to one side of the membrane. The stencil can be seen through the membrane. 
  • It can be helpful to leave a small section of the stencil loose for easier removal later.
  • Carefully paint the area on the opposite side of the membrane using a thick layer of carbon grease. This way the stencil can be reused.
  • Stay within the boundaries of the stencil. If a small amount of carbon grease gets outside the painted area, you can paint the leads through that area as described in this section
  • If multiple spots of carbon grease escape the active area, that actuator should be thrown away.
  • Hold the actuator up to a light source. Light will show through in any spots not covered.
  • Fill in any areas that present themselves.
  • After the first side is painted, remove the stencil and paint a thick layer of carbon grease on the second side so it matches the previously painted area.
  • Make sure the entire area is covered by grease.
  • Stay within the boundaries of the previously painted area.
  • A small amount of carbon grease escaped the active area in the video on the left, but it was not significant enough to redo the actuator.

Save any leftover carbon grease and cotton swabs for step 4.