Abstract: A precious metal coated interior and uncoated exterior catalyst is formed from a cylindrical substrate with a circumferential periphery and an interior honeycomb structure. A jacket of liquid impermeable material is wrapped around the substrate circumferential periphery, and the jacket ends are fastened together with hook-and-pile fasteners or the like. The wrapped cylindrical catalyst substrate is passed through a shower of precious metal liquid solution or suspension so that the honeycomb structure surfaces are coated with precious metal. Because the jacket is disposed around the substrate circumferential periphery, the circumferential periphery does not get coated. The jacket is removed by disconnecting the hook-and-pile fasteners, and the jacket can be rinsed off with a rinse liquid and the used rinsed liquid may be collected and used for subsequent substrate showers. The jacket is reuseable to wrap other substrates.

Abstract: An insulating system and the method for the preparation thereof, for preparing a catalyst substrate or catalyst to provide a final product wherein a packing and catalyst are insulated from each other. A thin coat of low viscosity ceramic inorganic fiber formulaton is applied to a clean dry substrate or catalyst to wet the surface thereof to facilitate adhesion. Then at least one coat of high viscosity inorganic fiber formulation including a quantity of hollow silica microspheres is applied to the thin coat to provide an insulating coating of desired thickness (e.g. 45 mils .+-. 15 mils). Then the insulating coating is dried. The high viscosity ceramic inorganic fiber formulation is preferably produced from the low viscosity ceramic inorganic fiber formulation by the addition of the hollow silica microspheres thereto, providing very precise viscosity control. The final substrate or catalyst coating system produced has a thermal conductivity of about 2.7 BTU in h.sup.-1 ft..sup.-2 F.sup.