2014-07-27 (Su) Conductive Paint Experiment

The response to my conductive paint experiment on sites like Hack A Day and Instructables.com has been phenomenal so I have kept experimenting with different parameters. Today may be the last day but then again someone may suggest something else that makes me want to pick up and try some more. I won't force it either way.

Someone on Instructables suggested mixing graphite powder with paint medium which eliminates paint pigments which may interfere with the resistivity. As it would happen, my roommate, who gave me the idea to start this experiment, had some gel medium which she donated to the experiment.

Enough background.

Black acrylic paint was purchased but the pigment is unknown. Ideally the pigment would be carbon. A swatch was painted on Friday and allowed to dry. No measurable resistance could be measured on the pure paint. The goal is to test two more substances with graphite powder in the same manner as the first three experiments.

 Materials for this experiment

Graphite powder was added to two jars. Black paint was mixed into the first jar at a ratio of approximately 1:1 by volume. The mixture was stirred with a toothpick. Once mixed a single heavy line was drawn before the toothpick was wiped off in the jar and allowed to dry next to the sample.

Amount of graphite in each jar
Line and toothpick covered in paint and graphite powder

Gel medium was added to the second jar at a ratio of approximately 1:1 by volume. The mixture was stirred with a toothpick. Once mixed a single heavy line was drawn before the toothpick was wiped off in the jar and allowed to dry next to the sample. The gel medium and graphite powder required more laborious mixing than the black paint and graphite powder.

Open jar of gel medium
Adding gel medium to graphite powder

Mixing gel medium and graphite powder

Lines and toothpicks drying

The samples were allowed to dry for five hours. No resistive reading could be taken from the gel and graphite powder after hours of drying. The black paint and graphite powder had acceptable readings.

Pure black paint
Gel medium and graphite powder
Black paint and graphite powder

Testing gel medium and graphite line

 Testing gel medium and graphite toothpick

Testing black paint and graphite line
 Testing black paint and graphite toothpick

Journal page

The rest of the posts for this project have been arranged by date.

A list showing of all the final posts of COMPLETED projects.

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  1. my name is David and want to know if it would be save if I apply this to my Yamaha DGX 300 key cantact strips. My email is hansidwk@gmail.com. I enjoy your advice and experiments.

    1. Hello David. I don't think this is the best solution. The DGX 300 has pressure sensitive keys. That's how you get your note pressure. This leaves me to believe that conductive paint will not work, at least not properly. If you keep the touch sensitivity off it may work but I wouldn't bet on it. Chances are, you'll have to find replacement touch pads for the keys which don't work. If the piano is headed for the trash bin, then it's worth a shot otherwise look around at what other people have done.
      If you give it a try, let us know the results, you're not the first person to fix a piano. I have hacked one back together myself. Nothing as fancy as your Yahama though.


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