Adhesion Test values.

[Joss10]

Dear mates,
A coating contractor has applied a HEMPEL epoxi (NOVOLAC)coating of high solids at erratic DFT 300/500 µm and adhesion test values also erratic 5/8 Mpa (100% adhesive failure), which would be a normally acceptable adhesion value for this product and DFT.
Thanks for any input.

 

[GGedge]

You could ask Hempel via the contractor if the product (or specification if there is more than one coat) has approval to ISO 12944-6 or 9, atmospheric and offshore respectively. If so ask for the independent test report which should quote adhesion tests before and after accelerated testing. Part 6 the minimum requirement is 2.5MPa but 0% adhesion failure unless value is >5MPa. For Part 9 the requirement is >50% of the value before accelerated testing, no value given for before testing. Not sure if either standard is relevant to the service condition you have. If you want to go that route, don't take my word for it get the standards and check the nuances and caveats.

Good luck.

Cheers

GG