Paint Thinning Lessons

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Lessons on Paint Thinning[edit]

The silver conductive paint from Less EMF: MG Chemicals 842-20G), is extremely viscous and expensive (about $30 for 0.7 oz or 20 g). Hence we decided to thin the paint by diluting it with household chemicals rather than purchasing a specialized paint thinner as recommended by many manufacturers. Neither water nor rubbing alcohol (iso-propanol), both of which are polar protic solvents, worked for diluting this paint. The polar aprotic solvent acetone, on the other hand, did work. We didn't try any nonpolar solvents like butyl acetate, because they weren't readily available.

In short, we found that dilution with acetone was easy and cost effective, since every hardware store carries it in the paint removal aisle and many fashionable friends have some as nail polish remover.

Chemicals in Conductive Paint Thinner[edit]

The choice of thinner depends on the medium, in which the conductive metal particles are suspended.

  • Acetone - cheap alternative to butyl acetate that dries quickly and meets our needs in silk screening circuits. It's also an ingredient in some commercial paint thinners.
  • Butyl acetate - the recommended thinner of conductive paints according to Less EMF. Forms of acetate are also common ingredients in commercial paint thinners.

Commercial Conductive Paint Thinners[edit]

  • SPI Thinner - Product #05004-AB; 05004-DA; 05004-RA Thinner Silver Paint
    • Acetone - More than 20%
    • N-butyl acetate - More than 15%
    • Ethyl acetate - More than 20%
    • Toluene - More than 20%