How to make conductive paint ( Graphite powder + Nail Hardener or Acrylic Varnish )

For a research project we needed to create a semi conductive layer around the test object. We tried silicone rubber and carbon black at university but could not achieve much conductivity. Our silicone rubber could not take much of carbon black in it and with high percentage of carbon black it turned into a solid paste which could not be cured. I therefore decided to take the matter to home and solve the issue at home. I bought Nail hardener and acrylic varnish from Action shop (The Netherlands), pretty cheap, each for less than 1.5 Euro.
Graphite powder was purchased from Ali express for ~ 5 Euro per 100 ml. I put the link in the description. Graphite powered is usually used as lubricant (for example if you want to lubricate piston of a model striling engine best is to use graphite powder).
It was found that for resistances in order-of 100s of Ohm/cm to a few kOhm/cm, 30% ratio or higher of graphite powder to nail hardener produce good results. For resistances in order of 10s of kOhm/cm to MOhm/cm 30% ratio or higher graphite powder to acrylic varnish gives good results.
Graphite powder:
nl.aliexpress.com/item/100500...
Finance: N=70
subs=2952
Available budget (N): 2952-100-70*(70+1)=-2118
Storage limit: 2^ln(2952)=254,27

[@YimingZang]

Very interesting! This likes a paper-made PCB😃.

[@SAMEDOKAWA]

Thanks!, very clearly and demostrative.

[@johnhamilton4816]

Outstanding!

[@rezadarani4166]

Nice! Very useful and interesting.

[@realflow100]

I achieved 0.5 to 2 ohms (yes single digit ohms) with graphite powder. 20 to 30% by weight polyvinyl acetate white glue/wood glue. to graphite powder and add enough water to form a semi-viscous wet paintable slurry. Mix thoroughly for at least 30 minutes to an hour. Preferably with a motorized mixer. will achieve much finer smoother and more precise conductive paint of high quality and low resistance. Don't make it too runny or thick or the layer thickness will be too high and make it less conductive. I even used cheap brand of graphite powder and it still worked great. It also depends what sort of surface is being painted. if the surface is porous. nonporous. plastic. metal. paper. etc. That also has a large effect on the conductivity of the resulting paint. Remember that common white glues like wood glue. PVA glue will likely already contain 50% water or solvent. So you'll want to account for that to achieve an accurate weight percentage of glue to graphite. An example you'd use 20 grams of PVA glue to 10 grams of graphite powder to achieve a 50% by weight glue to graphite powder ratio. This is because the PVA glue already contains approximately 50% water. I recommend adding just enough water first until the graphite powder is mixed in to get it smooth. Then add the glue and stir it in well. It will likely thicken substantially. You'll then want to add more water and stir for a long time until the desired consistency is reached. At first it will thicken up a lot. However after some time it will begin to become more smooth and fluid and less thick. This is a good sign and means it is close to being ready to use. Mix until it no longer changes in consistency much. Add additional water if too thick. but don't overdo it. You can paint it or use a syringe to deposit it on the surface depending on the thickness of the graphite paint you've made. Thinner more runny paints will create thinner smoother layers that are more even. but may be more difficult to apply in some areas. Thicker more viscous paint will create thicker layers Too thick or too thin will increase resistance. Higher percentage of glue to graphite will be stronger as well. but lower conductivity. I also recommend using a precision scale to help with the measurements to obtain a more accurate mixture.

[@suprayogi340]

very interisting tanks vrymuch...good luck

[@ishkhan2501]

perfect idea

[@soulrobotics]

i wonder if that painted surface could be platined with copper or nickel by an electrolytic bath.

[@gucdude]

very cool! do you think nail hardener could be swapped for nail clear coat? is it just the nitrocellulose lacquer that is the main carrier of the graphite?

[@DIYHomeAppliancesRepair]

Very nice, You can compare again up to 80% grafite

[@user-kg5ow8jf7f]

Can you show me your formula of this for research purposes only thank you

[@user-ld2iy4fo6g]

Do you know how these paints work on 3Dprints for electroplating?

[@donxgraphics]

Use graphite powder mixed with acrylic paint 2:1 ratio for electroplating

[@goguyted]

​@@donxgraphics2 parts graphite powder to 1 part acrylic paint? By volume or by weight? I am new thanks

[@kace1979]

What will be the application we can use as a trial?

[@HVE]

Sometime you need to make a surface conductive (for example to create some sort of shield), you can use the paint to make it conductive. Sliver paint is usually used, but that is rather expensive. Another example: if you have a circuit board that deals with tiny value of currents, you can use conductive paint to create electrical connections.

[@joshuastewart123]

Efield shielding may be a good option since all you need to do is fix it to a specific potential and the resistance isn't too important. This would be horrible for a PCB in most applications. I'm hesitant to say all because thats harder to state. The width of this paint is over 1 cm and is already kOhms. A PCB trace with low current is likely going to be be much much thinner meaning the resistance in this is going to be very very high. This is not practical, but still a cool experiment.

[@kace1979]

​​@@HVE Thank you very much for the explanation! God bless you!

[@kace1979]

​@@joshuastewart123 Thank you and God bless you!

[@dkjawahar-techexpt671]

If your graphite paint can show resistance below 5.0 ohms. It will be useful. You are showing resistance as high as 1.0 kiloohms, it will not be useful in battery making. If you have any alternative paint for less than 5.0 ohms, kindly share it reply. Respect from Jawaharlal Bharat INDIA 🙏