When the need for weld repairs arises, often so does the pressure to fix the equipment quickly and resume operations with minimal downtime.
However, hasty and inadequate repairs can reveal themselves to be costlier in the long run, and caution should be exercised.
Even before the welding process takes place, the initial cause of the defect should be determined. Post-deformation root cause analysis, or simply failure analysis, can be instrumental in pinpointing what exactly has caused the damage in the first place.
The underlying reasons can range from faulty initial fabrication (either inadequate materials or workmanship), to normal in-service defects or fatigue cracks, degradation due to external factors (moisture, temperature), and improper use, such as exposing the equipment to weight loads past its certified load limit.
While in the short term, fixing the existing defect is important, it is even more so to determine its cause correctly, so as to curb, and ideally prevent, its future occurrence.
While welding processes can vary significantly based on the application, the following best practices should be included in any welding procedure. First and foremost, all surfaces to be welded need to be cleaned, including removing any grease, dirt, oxidation and paint if present.
Neglecting this crucial step may result in porosity or impurities in the weld metal, impacting its physical characteristics and making it potentially more susceptible to cracking. Occasionally, components may need to be re-welded. In this case, old weld should be removed by way of gouging or grinding, paying attention not to remove the base metal where possible.
The new welding should then wholly fill and eliminate the discontinuity in the metal. Finally, post-weld inspection is a critical element of any welding process. In fact, when done incorrectly, repairs can create a ripple of new issues.
While the key takeaway is “fix it properly to avoid having to do it again”, the fundamental question in welding is whether a weld repair is advisable at all.
Should a new part be perhaps preferred instead?
Points to consider are the safety implications of a potential catastrophic failure, any impact on service life or performance, and the presence of any standards or regulations barring the use of welding in your particular application.
Hooks, for instance, are a quintessential example of an item that should be replaced, never repaired, as the consequences of its failure while carrying a heavy or hazardous load can be devastating.
When performed correctly, a weld repair can yield a product which performs over and above its design requirements, saving you both time and money in maintenance and repair overheads, and extending its overall in-service life.
However, welding is a process where experience and know-how are indispensable, and resorting to the services of professionals is highly recommended. Call us today and we can discuss how best to amend your repairs.