When sheets need to be cut on site the most suitable technique is with nibblers or power saws with metal cutting blades (tin snips can be used although they are difficult to use on profiled sheeting). The use of cutting discs and grinding wheels is not recommended as they generate very hot particles which can damage the coating.
BlueScope Steel recommends the use of cold cutting saw with appropriate blades.
Don't forget to clean up each day. Offcuts and other metal scraps, such as pop rivet stems and fasteners, if left on COLORBOND® steel, may cause rust stains which detract from the finished appearance. Swarf (steel debris produced by drilling and cutting etc) should be swept or hosed from the job each day.
Care should be taken if hosing off a roof into gutters already installed. The swarf should not be left to sit in the gutters. Maximum care should be taken when attempting to detach swarf which has become stuck. This can be done, but no action which is likely to remove the paint or metal coatings should be attempted. For critical applications, inspection of the job should be made after two weeks when rain or condensation will have caused any remaining swarf to rust, and will highlight affected areas for a more thorough cleanup.
Sheets should not be dragged across others as scratching will result. Spray packs should not be used to repair any scratches. The paint fades differently. Small scratches are best left alone. If the damage is severe it is best to replace the panel.
Never use black lead pencils for marking galvanised, ZINCALUME® steel or COLORBOND® steel. Black lead pencils are made from graphite which will react with the coating on these products resulting in corrosion of the coating. The answer is to use any colour pencil but black and clean off any markings as soon as possible.
This information is intended as a guide only. For detailed assistance with your particular application, please contact us.