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HDG immersed and painted

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chrysa1975

Materials
Nov 14, 2007
64
Dear all, there is a contract requirement for the supports of marine fenders, to be hot dip galvanized and overcoated per ISO 12944-9. I have an objection and I need your help.
These items being hot dip galvanized, they cannot be used in splash / tidal and immersed services as it is clearly depicted in ISO 12944-5 Annex D and ISO 12944-9 Table 3. They can be exposed to a CX environment with 200μm minimum painting system (Table 3 ISO 12944-9) but they cannot be immersed or used in the splash/tidal zone.
Kindly provide any opinion. Thanks in advance.

 
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ISO 12944-5 doesn't say galvanized and painted "cannot be used" for immersed conditions; the text under Table D1 says it is possible but needs special consideration. ISO 12944-9 gives minimum requirements for various categories and it is correct the immersion categories don't include galvanizing and paint (assuming one discounts galvanizing as one of the "other primers" options). However, it might be argued that absence from minimum requirements is not the same as saying "cannot be used".

You could reasonably go back, to whoever wrote the contract requirements, and say ISO 12944-9 has no specification for galvanize plus paint for immersion service could they please clarify the requirements?

Cheers

GG
 
GGedge I appreciate your reply, although it is based on a logical interpretation of what is specified in the ISO. Υou are correct that the phrase "cannot be used" is wrong. However I dont think it is an absence from minimum requirements. ISO does not bless it, implying also that dedicated tests for the actual conditions shall be performed.
I guess we have to find a paint manufacturer with a solid track record that can undertake the tests and the responsibility.
Any other opinion is welcome.
 
Agreed. Any specification to Part 9 should be qualified by testing to Clause 9. In many cases for the types of specs given in Table 3 the supplier will have independent test data. In this case they probably do not so would need to arrange that testing. I would imagine they might be reluctant to do so as it is slow, expensive, and they might be concerned the system would not pass. So anticipate they will suggest/recommend the alternatives. To an extent how you deal with that might depend on where in the contract you are, is it tender or has the contract been awarded.


GG

 
The project is ongoing... Thank you so much for the additional reply!
 
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