A question about hardware corrosion.
The majority of my AN hardware is the standard steel alloy cadmium plated stuff. I'm using stainless steel machine screws for attaching aluminum skins that are exposed to most weather, but cadmium stuff everywhere else.
My question is this.. is cadmium plating enough to handle long term exposure to the elements? I'm building nearby some guys restoring old WW1 and WW2 biplanes, and they are either spraying all their hardware (yes, each individual nuts,washers andbolts) with 2kprimer, and some are applying some anti-corrosive compounds over and above.. and have suggested I do the same!?
All the pics I see of completed biplanes seem to show the only color coated hardware is for aesthetics.. and not for corrosion resistance - but I thought I should check in and see?
Am I supposed to be painting all my bolt heads - or is that just a legacy of days gone by?
Further to this, but slightly different, should I be covering bolt shanks and insides of bushings with some of the anti-corrosive compounds and dissimilar metal stuff - particularly engine mount bolts? I have got this stuff called Duralac which is much like the marine jointing compounds, and used by Boeing apparently.
Oh, btw.. I live in a high humidity and high rainfall area !