Quote: (Originally Posted by
Dave Sutton)
....
The deal is that the teflon coated (white) spheres are parkerized before being coated on the exterior. The parkerizing is a black/grey phosphate treatment that is very corrosion resistant. Apparently the LDS has only ever seen bright galvanized cylinders shining brightly in the glare of their inspection light, and mistook the parkerized finish for rust (fools). .
Funny,
The thing about parkerizing is actually interesting. From a thread on DecoStop i cleaned some very rusty Steel 15l. last year with a phosporic-acid solution. This can give a very thin parkerized protection inside that holds up better than raw steel. Cleans out the rust nicely as a black phosphate-solution. Some in my diveclub predicted I would die on first dive afterwards (apparently they don't know whats in Coca-Cola)
See:
The Deco Stop (Long thread)
Parkerizing - Wikipedia, the free encyclopedia