PROTECTING FURNACES AGAINST CORROSION, ABRASION AND THE LIKE THROUGH THE APPLICATION OF COATINGS OF SPRAYED METAL, RUBBER AND PLASTIC MATERIALS; SAND BLASTING OF SURFACES TO PREPARE SAME FOR METAL SPRAYING, RUBBER LINING, PLASTIC MATERIAL COATINGS AND FOR OTHER PURPOSES; CONCRETE DEMOLITION; BOILER REPAIR; AND THE RENTAL OF CONSTRUCTION EQUIPMENT-NAMELY, PORTABLE COMPRESSORS, CRANES, SHOVELS, PUMPS, AND AIR TOOLS