Barrier Properties & Galvanic Corrosion Resistance

Galvanic corrosion is a specific and particularly damaging form of corrosion that occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte. It is a common and significant problem in offshore structural assemblies, marine hardware, aircraft landing gear, and any industrial application where steel, aluminium, copper alloys, and stainless steel components are joined or in contact. Reducing galvanic corrosion requires interrupting either the electrical pathway, the electrolyte pathway, or both — which is precisely what Gentoo's electrically insulating, hydrophobic film achieves.

Barrier Properties — Electrochemical Impedance Spectroscopy (EIS) Testing

Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the barrier properties of Gentoo against a standard polyurethane topcoat control. Aluminium alloy 2024-T3 (UNS A92024) coupons were coated with MIL-PRF-85285D grey polyurethane at 1.0 mil thickness. A subset of coupons received Gentoo treatment over the polyurethane topcoat. All coupons were tested with and without the Gentoo addition.

Initial (dry) EIS measurements showed similar impedance values across the full frequency range for both the polyurethane-only and Gentoo-treated coupons — confirming that Gentoo does not compromise the baseline electrical properties of the underlying coating system.

Following 336 hours of ASTM B117 salt fog exposure, the coupons were re-tested. The polyurethane-only control samples showed a significantly larger reduction in impedance — approximately two orders of magnitude — compared to the Gentoo-treated samples. This result directly demonstrates that Gentoo provides measurably superior barrier protection against moisture and ion penetration under accelerated salt fog exposure conditions comparable to prolonged offshore and coastal industrial service.