A composition that penetrates surfaces of equipment for use with an uncured cementitious material, such as uncured concrete includes an aqueous solution with colloidal silica. Pretreatment of a surface with such an aqueous solution may reduce or eliminate adhesion of uncured cementitious material to the surface. A composition that cleans hardened and/or cured cementitious material from the surfaces of such equipment also includes an aqueous composition with colloidal silica. Hardened and/or cured cementitious material may be removed from equipment surfaces by applying the hardened and/or cured cementitious material with the aqueous solution to soften the cementitious material and optionally abrading the softened cementitious material to mechanically remove the same from the equipment surfaces. Systems for removing hardened and/or cured cementitious material from the surfaces of equipment capable of use with uncured cementitious material include an aqueous solution with colloidal silica and a mechanical removal component.

A rust inhibiting process 100 for cleaning and protecting a target object 902 is disclosed. Comprising mixing at least a rust inhibitor 620 and a fluid 618 into a slurry mixture 608, spraying the slurry mixture 608 at the target object 902 from within a reservoir 610 of a slurry blasting system 202, separating a tarnished top layer 906 and a parent metal 904 of the target object 902 with a slurry stream 908, cleaning the parent metal 904 with the rust inhibitor 620, preventing the parent metal 904 from impregnating with contaminants during cleaning with the rust inhibitor 620, and protecting the parent metal 904 with the rust inhibitor 620 after spraying is complete. The slurry stream 908 comprises the slurry mixture 608 of the slurry blasting system 202 being sprayed with the slurry blasting system 202. The slurry blasting system 202 comprises a tank 204.

A cast steel shot media for performing a blasting treatment, including, at a weight ratio, 0.8% or more and 1.2% or less of C, 0.35% or more and 1.2% or less of Mn, and 0.4% or more and 1.5% or less of Si, in which a remainder has a hyper-eutectoid composition including Fe and inevitable impurities, and the cast steel shot media has a structure having a fine pearlite structure as a main constituent.

A cast steel shot media for performing a blasting treatment, including, at a weight ratio, 0.8% or more and 1.2% or less of C, 0.35% or more and 1.2% or less of Mn, and 0.4% or more and 1.5% or less of Si, in which a remainder has a hyper-eutectoid composition including Fe and inevitable impurities, and the cast steel shot media has a structure having a fine pearlite structure as a main constituent.

A blasting or stripping booth is provided creating a generally downward flow for treatment of fluid and particle flow, which reduces operator exposure to potentially hazardous debris. The booth comprises an enclosure defining an upper region for a workpiece, a lower region, and a separator assembly. In some instances the separator assembly includes individual separator units which are discrete units, each having a generally square or rectangular plan view configuration which are arranged in an array for providing the required process flow capabilities. Further embodiments utilize structures forming the separator which have an elongated trough-like configuration. These embodiments find a particular application in large-scale stripping or blasting booth used in production environments where workpieces may flow through a treatment system in a serial manner. Other suitable applications include batch type processing of parts.

A cover for an electronic device and methods of forming a cover is disclosed. The electronic device may include a housing, and a cover coupled to the housing. The cover may have an inner surface having at least one of an intermediate polish and a final polish, a groove formed on the inner surface, and an outer surface positioned opposite the inner surface. The outer surface may have at least one of the intermediate polish and the final polish. The cover may also have a rounded perimeter portion formed between the inner surface and the outer surface. The rounded perimeter portion may be positioned adjacent the groove. The method for forming the cover may include performing a first polishing process on the sapphire component using a polishing tool, and performing a second polishing process on the groove of the sapphire component forming the cover using blasting media.

A cover for an electronic device and methods of forming a cover is disclosed. The electronic device may include a housing, and a cover coupled to the housing. The cover may have an inner surface having at least one of an intermediate polish and a final polish, a groove formed on the inner surface, and an outer surface positioned opposite the inner surface. The outer surface may have at least one of the intermediate polish and the final polish. The cover may also have a rounded perimeter portion formed between the inner surface and the outer surface. The rounded perimeter portion may be positioned adjacent the groove. The method for forming the cover may include performing a first polishing process on the sapphire component using a polishing tool, and performing a second polishing process on the groove of the sapphire component forming the cover using blasting media.

Apparatuses, components, methods, and techniques for selectively texturing concrete surfaces are provided. An example method of providing a surface portion of an architectural precast concrete wall panel with an abraded texture is provided. The method includes a step of spraying a surface portion of an architectural precast concrete wall panel with an aqueous-based particulate abrasive mixture under conditions adequate to at least partially abrade the surface portion. An example sprayer system for abrading a concrete surface is also provided. The system includes an aqueous-based particulate abrasive mixture dispenser including a spray nozzle arrangement. The system also includes a material communication assembly in abrasive flow communication with the aqueous-based particulate abrasive mixture dispenser. The system also includes a dispenser positioning arrangement.

Apparatuses, components, methods, and techniques for selectively texturing concrete surfaces are provided. An example method of providing a surface portion of an architectural precast concrete wall panel with an abraded texture is provided. The method includes a step of spraying a surface portion of an architectural precast concrete wall panel with an aqueous-based particulate abrasive mixture under conditions adequate to at least partially abrade the surface portion. An example sprayer system for abrading a concrete surface is also provided. The system includes an aqueous-based particulate abrasive mixture dispenser including a spray nozzle arrangement. The system also includes a material communication assembly in abrasive flow communication with the aqueous-based particulate abrasive mixture dispenser. The system also includes a dispenser positioning arrangement.

An electrostatic spray application apparatus and method for producing an electrostatically charged and homogeneous CO.sub.2 composite spray mixture containing an additive and simultaneously projecting at a substrate surface. The spray mixture is formed in the space between CO.sub.2 and additive mixing nozzles and a substrate surface. The spray mixture is a composite fluid having a variably-controlled aerial and radial spray density comprising pressure- and temperature-regulated propellant gas (compressed air), CO.sub.2 particles, and additive particles. There are two or more circumferential and high velocity air streams containing passively charged CO.sub.2 particles which are positioned axis-symmetrically and coaxially about an inner and lower velocity injection air stream containing one or more additives to form a spray cluster. The axis-symmetrical CO.sub.2 particle-air streams are passively tribocharged during formation, and the spray clustering arrangement creates a significant electrostatic field and Coanda air mass flow between and surrounding the coaxial flow streams.