4 Issues You Should Plan For Before Patching Sheet Metal
Fabricators and manufacturers who use sheet metal may need to add a patch to sheet metal due to several reasons, such as the need to compensate for the thinning that may have occurred during sheet metal processing/fabrication. However, adding a patch on that sheet metal should be done carefully so that it doesn't cause future problems. This article discusses some of the future problems that you should mitigate against as you apply a patch on sheet metal.
Susceptibility to Corrosion
Localised corrosion can easily develop in the gap that exists between the sheet metal and the patch. This corrosion can contaminate the products that are being processed using the machinery that was made using that patched sheet metal. You can avert this corrosion by galvanising the patch. Alternatively, you can treat the patch and the section where the patch will be placed with anti-corrosion agents so that you keep localised corrosion at bay.
Premature Aging of Adhesives
Some adhesives that are used to attach patches to sheet metal can degrade until the patch becomes detached from the metal. Heat exposure can also reduce the effectiveness of some adhesives. The detachment of the patch can cause components to fail. You can guard against this problem by selecting adhesives whose service life matches the service life of the equipment that you are making. You can also select adhesives that are heat-resistant so that they can work despite exposure to intense heat.
Problematic Downstream Processing
Adding a patch on sheet metal can complicate other fabrication steps later on. For example, the patch can reduce the formability of the sheet metal. Spring-back can also increase during bending or folding processes. These problems can be reduced by using a patch that is made from the same metal as the sheet onto which the patch is being placed. Appropriate pre-treatment of the patch, such as preheating, can be done in order to compensate for the reduced formability of the material.
The process of preparing patches can be wasteful. This is because pieces of scrap are created when an existing piece of metal is cut in order to fit onto the area where the patch is needed. Some of those scrap pieces can injure employees who may accidentally touch them. The effects of scrap generation can be reduced through strict adherence to good housekeeping practices, such as regular cleaning of fabrication shop floors. You can also restrict the materials from which patches are made to leftover materials from other processes. In this way, you will avoid wasting fresh materials that could have been used to make new components.
The best way to avoid the problems created when patches are used is to prevent the need to put a patch on sheet metal. Talk to your sheet metal supplier for possible solutions to this problem. For instance, he or she may advise you to buy thicker sheet metal that can handle different loads.