To give you an example of what the correspondents are referring to, I secured the spar pin wires to the fuselage where they come out of the cross conduit with a dab of silicone and left it to set overnight. Came back the following morning and the protruding part of the spar pin was rusty red !
Fortunately, It came off with a very light rub with grey Scotch and was then liberally coated with light oil.
Showed how the off-gassing fumes of acetic acid from the curing silicone had fallen down onto the steel and started corrosion.
"I add a little excitement, a little spice to your lives, and all you do is complain!" - Q
Donated in 2018