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.
We have analysed seven paint schemes using five accelerated corrosion tests (ISO 4623/2, GM9540P-B, D172028, ISO16701 & BS3900:F12) of three month duration. We compared these test data 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.
Prior to testing, we assessed the mass, the gloss (at 20/60/85º geometries), the colour (L, a and b colour space) and the dry film thickness and kept visual records of the specimens. We then monitored these characteristics over the duration of the test. We also carried out 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, we performed two accelerated test regimes, chosen by the client, for analysis on two different substrates.
As in Phase 1, we monitored the gloss, the mass, the colour and the visual appearance over time. In addition to these characteristics, we also undertake a 4 month UV analysis 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 2021.