kengr

Materials science can be very picky. Part numbers were written on a titanium sheet intended to be used for one of the prototype Blackbirds. The next morning they had a stencil, with the places where they had written reduced to powder on the floor. Turns out the ink used in the marker contained ammonia.

John D. Clark's _Ignition! An Informal History of Liquid Rocket Propellants_ is full of similar cautionary tales. Like the young propellant chemist who didn't know that the "I" in IRFNA stood for "Inhibited" and ordered a batch without it. Then wondered why his nitric acid turned green and started dissolving the drum...