Stainless Steel – How the Fabrication Industry Combats Weld Burn
Stainless Steel has long been regarded as the premier choice of metal for use in fabrication projects as diverse as fitting out factories and installing public convenience facilities. It is highly malleable so can be manipulated into almost any shape imaginable, provides strength and durability, facilitates cleaning and can be coated with anti-bacterial agents, and – if installed properly – has a smart appearance.
However, the welding process used in fabricating Stainless Steel fittings can leave behind residual bluish and black marks or discolouration commonly referred to as 'weld burn'. Before signing off on a project, especially if aesthetic concerns are a major factor (for example if a project is located in a public space or retail environment), most welding professionals will insist that this is adequately addressed using one or a combination of the following techniques.
Pickling Paste – The Traditional Method
Also available as a liquid or 'solution', 'Pickling Paste' is a compound of strong acids which can be applied to metal surfaces in order to dissolve impurities such as corrosion, or indeed weld burn, which can then be easily removed. While this tried and tested technique is reliable, due to its toxicity considerable care must be taken at all times, including the use of appropriate safety clothing and stringent safety protocol. Waste product must be disposed of safely, and there are intrinsic ecological disadvantages which are extremely difficult - if not impossible - to eliminate.
Electro-Chemical Weld Burn Removal – A Safer, Cleaner, Faster Solution
By using specially designed electronic apparatus in conjunction with certain chemicals, it is possible to remove weld burn without the need for the much more hazardous substances used in the composition of Pickling Paste. Results are comparable and can be achieved more quickly, and equipment can either be hired or purchased outright depending on requirements.
Mechanical Abrasion – Effective But Limited
Where access is possible, a circular abrasive pad attached to a rotary drill can be used to remove weld burn. However, removing weld burn using this method is time-consuming, and care must be taken to avoid scratching the Stainless Steel surface. Although ineffective for use in the removal of weld burn from intricate welded Stainless Steel components, this technique is often used in alongside the Pickling Paste method in order to limit the amount of hazardous material required.
Painted Stainless Steel – An Attractive Alternative
Especially suited to applications in which a high-quality finish is required, coating Stainless Steel with a suitable primer before painting eliminates the need to remove weld burn at all. Adequate primer is essential to avoid any inconsistencies in the final finish, especially if a lighter shade is chosen. While this method offers a great deal of choice and an attractive final result, it is both time-consuming and expensive.