What chemical is it? or is it full of secret ingredients?
There you go @IronGiant data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
Hang on, that's the sealing mix data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7I'm interested in the chemical reaction that makes it corrosion resistant and black, or not with this chassis data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
CuSe apparently.
Ta!!
Ah - the original words ran 'applied' and 'sealed' together! Must read more carefully //static.avforums.com/styles/avf/smilies/facepalm.gifdata:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
I don't have the specifics for this product, but the data sheet from a competitor that does the same job (chemical blacking of iron and steel) contains:
Nickel sulphate (2-10%), Copper sulphate (2-10%), Potassium Bifluoride (<2%) and Selenium compounds (minus cadmium sulphpselenide).
Not being a chemist I wouldn't be able to tell what does what and how, but it's identical the last chassis we blacked, and that one ended up a uniform satin black, so it's a bit of a mystery at present. We'll see how today goes... data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
Shamelessly copied from Wikipedia:
Cold black oxide[edit]
Cold black oxide is applied at room temperature. It is not an oxide conversion coating, but rather a deposited copper selenium compound. Cold black oxide offers higher productivity and is convenient for in-house blackening. This coating produces a similar color to the one the oxide conversion does, but tends to rub off easily and offers less abrasion resistance. The application of oil, wax, or lacquer brings the corrosion resistance up to par with the hot and mid-temperature. One application for cold black oxide process would be in tooling and architectural finishing on steel (patina for steel).
Some elbow grease and persistence always pays off...
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That's more like what we expected - uniform, tidy gun metal in appearance. It's taken a second coat so more blacking agent is required, but it's working properly at least. No more heat-cycled-titanium-bluey-weirdness//static.avforums.com/styles/avf/smilies/clap.gif.
That looks much better, any idea what went wrong the first time?