ShaliFerroBlack BT (formerly known as STPFerroBlack) is an economical water based Bituminous EmulsionPaint specifically designed for for corrosion protection of rails, covered byIndia Patent No. 56192 conforming to Indian Railway Specn. IRSP: 30: 1996. ShaliFerroBlack BT is a colloidal clay type bituminous emulsion whichcan be applied in thick coats, even on vertical surfaces. It does not flow at hightemperatures, nor does it loose its ductility when temperature is low.