Tanks and military platforms are coated to provide corrosion protection amongst other functionalities. Some corrosion inhibitors are however harmful to human and environmental health and no longer comply with REACH legislation (Registration, Evaluation, Authorisation & restriction of CHemicals)
nC² has been working with DSTL to find alternative products free from substances of very high concern (SVHC’s) by evaluating coupons which have undergone accelerated corrosion tests to ISO/commercial standards.
Seven paint schemes were analysed using five accelerated corrosion tests (ISO 4623/2, GM9540P-B, D172028, ISO16701 & BS3900:F12) of three month duration. These data were compared to outdoor exposure tests carried out for eighteen months in two static locations and one on vehicles; these were used to replicate the typical UK conditions.
The mass, gloss (at 20/60/85º geometries), colour (L, a and b colour space) and dry film thickness were assessed along with a visual records of the specimens prior to testing. These characteristics were then monitored over the duration of the test along with cross hatch adhesion and a visual assessment of blistering of the coating or corrosion of the substrate.
The results from Phase 1 identified a coating and primer that out performed the other coatings. For Phase 2 of the project two accelerated test regimes were chosen for analysis on two different substrates.
As in Phase 1, the gloss, colour and visual appearance was monitored over time. In addition to these characteristics a 4 month UV analysis was undertaken to BS EN ISO 16474-3 as well as pull-off adhesion, scratch resistance and various immersion tests in different media.
Testing is ongoing and due to recommence in 2020.