I found a reasonably priced source for Liquitex Water based spray can acrylic. This works well over foam and easy cleanup with water or Windex.

Sellers web site is: Utrecht Art Supplies   https://www.utrechtart.com.

Liquitex has been used by the RC crowd on foamies and will work well for electrics. It is available at a number of different Art stores but this one had the best price.

Best,   DennisT