Design Life and Coating Selection and Application
Design Life and Coating Selection and Application
(OP)
Dear Forum's members,
Does any one know what is the influence of design life on coating selection and its application? For example if I want to make an offshore structure with 5 years design life, would the coating specification be different with the one has 20 years design life? What is the different?
Thank for your attention and help.
Does any one know what is the influence of design life on coating selection and its application? For example if I want to make an offshore structure with 5 years design life, would the coating specification be different with the one has 20 years design life? What is the different?
Thank for your attention and help.





RE: Design Life and Coating Selection and Application
Steve Braune
Tank Industry Consultants
www.tankindustry.com
RE: Design Life and Coating Selection and Application
Back to the original question specifically: there's always a trade off of the total service life of the structure, minimizing maintenance costs, and minimizing acquisition costs. The challenge is saving money NOW is always more attactive to those who have to pay for it.
Only once did I spec out the paint system for a short service life structure. This was a test structure that was planned to be used for only 3-4 years (and hence the owner didn't want to spend much). I spec'd out a "minimal" low-cost paint system that I thought would last 5 years, and be easily touched-up or recoated later if required - a slight overkill p[robably. 10 years later, the test structure is still in service!
RE: Design Life and Coating Selection and Application
For further reference, have a look at ISO 12944 'paint and varnishes - Corrosion protection of steel structures by protective paint systems'. For large projects (in Europe anyway) this is normally specified.
This standard covers the the through life coating system, and breaks the application into environment (ie corrosive, industrial, submerged) and durability (in years). Depending on these variables, it gives detailed recommended coating systems.
For the offshore projects I've been involved with, the submerged zone must be either coated OR cathodically protected, as well as a corrosion allowance in the steel supplied. Further guidance refer to NORSOK M-501.
Hope that helps.
RE: Design Life and Coating Selection and Application
A "normal" coating system that would get 15yrs life in an industrial environment might only make it to 5yrs in an offshore situation.
IMHO a decent multicoat system is cheap insurance. I would hold fast to recommending a "proper" system and it will be less susceptible to failure prematurely if the applicator messed up somewhere that the QA/QC didn't pick up.
Cheers
Rob