A method for determining the porosity of Au deposits on small surfaces, such as printed circuit boards, elec. contacts, and probes, is based on the property of Ag to plate on non-Au surfaces but not on Au. Ag plates out on pores in Au on exposed base-metal substrates. Parts are immersed in M AgNO3 solution in glass-stoppered bottles, placed in an oven at 70° for 24 h then left at room temperature for 10 h. When removed and carefully rinsed, Ag spots, spikes, and coatings indicate where porosity exists. Measurement of current flow for 6 min in a cell consisting of Ag-coated Au samples as the anode against a Ag cathode as generated by a 0.63 V power supply is proposed as a measure of the porosity.