Hyrdotesting after painting.

[KiwiTanks]

I am looking for people's opinions on the practice of painting a tank prior to the hydrotest. I remember seeing a thread on this before, but can't seem to locate it again.

Due to the onslaught of winter, we have a contractor who would like to internally line the floor and first strake of a new tank prior to a hydrotest. The client has already agreed to the painter externally coating the tank during construction (and hence prior to the hydrotest).

Is this an accepted practice (Nothing specific in API650 from what I can tell)?
What additional testing would be the norm prior to lining the floor and first strake - considering that the floor welds have all been visually and Vac box inspected?

 

[IFRs]

If the purpose of the hydro is to test the basic ability of the tank to hold liquid without bursting, painting makes no difference. If the purpose or part of the purpose of the hydrotest is to check for leaks that may have been missed by the shell and bottom NDE then painting is a bad idea. Note that per API the hydrotest is a shell test, not a bottom test.