Thanks for all the information provided through the different replies. When i installed all the fittings i scanned all the different forums
and there was a mix of :
A)Let it clean
But nobody was complaining about rust in a "clean" installation
. Furthermore, Sta-Lok instructions are not clear... they say:
Interior water proofing is not essential but will prevent water collecting in the bottom of the fitting.
Since i doubt the marine
terminal are installed in a living room... those people at Sta Lok know that 90 % of their terminal will be installed in a salted environment
(supposing the 10 % are in fresh water). Thus saying that "interior water proofing is not essential" led me to the conclusion that it was a rhetoric choice but not an essential thing to do.
Now after 2 months on the water with a brand new boat - self constructed - i just put the rigging
on... having a look at those rusty fittings is not inviting at all. I think the only reasonable thing i can do is to dismantle them all, clean them and caulk.