The primary objective of this project is to validate the performance of Ecosil’s SILSBOND wash primer replacement per TT-C-490F specifications and gain approval for the relevant Qualified Product Database (QPD). Once validated, this technology will be demonstrated at the user level via field testing on non-critical military hardware for one year duration.

Technology Description

SILSBOND is an organic-inorganic hybrid pretreatment that synergistically combines advanced silicon compound oligomers and water-soluble inorganic compounds to form a nano-structured film on a metal surface by immersion or by simply spraying-on and drying-in-place. No additional de-ionized water (DI water) rinse step is needed after spraying the pretreatment coating (e.g., wash primer). SILSBOND formula is 100% hexavalent chromium (Cr(VI))-free and phosphate-free and therefore is a non-toxic, environmentally-compliant chemical formulation. The pretreatment film significantly enhances the corrosion resistance of metals by offering excellent paint adhesion for a wide variety of paints. Its superior performance has been demonstrated on multiple metal substrates in government-funded research projects as well as confirmed by pretreatment end users in different industries. SERDP project WP-1675 demonstrated that SILSBOND can perform as well as the DoD-P-15328D chromated wash primer in ASTM B117 neutral salt spray (NSS) and the GM 9540P cyclic tests on cold rolled steel, AA 2024-T3 and AA 7075-T6 aluminum alloys under MILDTL-53022 and MIL-DTL-53030 epoxy primers.

Recent lab testing at the Army Research Laboratory (ARL) has also confirmed the performance of SILSBOND (test sample code: “Eco5-1”) as a promising wash primer replacement. The SILSBOND system will be tested via each performing laboratory to meet the requirements specified in TT-C-490F. Once the SILSBOND wash primer passes all required tests outlined in the mil-spec and 12-24 month outdoor exposure test, a one year field test will be initiated. The field testing of the SILSBOND wash primer will be on non-critical Army and Marine military hardware incorporated in full military coating and evaluated for duration of one year.


The expected benefit to the Department of Defense (DoD) is a robust, environmentally benign, repairable Cr(VI)-free and phosphate-free wash primer pretreatment coating that will further populate the QPD, which will give end users options when the DoD-P-15328D specification is eventually cancelled. This will provide the Army and Navy with an additional wash primer system that can be added to the Qualified Products List (QPL), giving the DoD more options from which to implement new technology for specific applications. Currently there is only one phosphate-containing wash primer that is a qualified alternative. SILSBOND is considered a “drop-in” replacement for the current DoD-P-15328D wash primer. Having alternatives gives the DoD choices without relying on one material or coating.(Anticipated Project Completion - 2018)