Epoxy coating is often applied to sheet metal to act as a permanent protective barrier. Sheet metal that has an epoxy coating on it is protected from chemicals penetrating and corroding the metal. This epoxy coating has to be removed from the sheet metal in order to be able to weld it to another piece of metal. If not, the weld will not hold and that is assuming you get through the thick epoxy coating. Removing an epoxy coating is not that difficult of a job and can easily be accomplished. The following article will show you how to remove the epoxy coating from the sheet metal.
Step 1 - Flapper Wheel
Attach the 60-grit flapper wheel to the angle grinder before doing anything else. A normal grinder with any other disc will cause serious problems with removing an epoxy coating. Using an angle grinder with the flapper wheel is the only acceptable way to remove epoxy coating from sheet metal. If you try to use a normal grinding disc the epoxy coating will clog the grinding disc very quickly. When this happens the grinding disc will heat up the sheet metal but will not remove the epoxy coating. The flapper wheel construction is made with this in mind and keeps everything cool. This allows the epoxy coating to taken off the sheet metal.
Step 2 - Be Safety Conscious
Before you begin using the angle grinder to remove the epoxy coating you need to protect yourself. Many things can go wrong and hurt you. For example you will need to be mindful of sparks that will be created during the removal process. These sparks can damage your skin and your eyes. You also need to look out for pieces of flying hot plastic. Make sure you have your protective glasses, face shield and gloves on to avoid any potential damage.
Step 3 - First Sanding
Turn on the angle grinder and slowly lower it to the sheet metal. Use medium pressure and begin to grind away the epoxy coating. Continue until you think you have gotten all of the epoxy coating. You can turn off the grinder and wipe down the sheet metal to double check your progress if you like.
Step 4 - Finishing up Removing the Epoxy Coating
Don't be surprised if you don't remove all of the epoxy coating because it is very thick. This next step will show you how to remove the last bits of epoxy coating. Remove the flapper wheel and replace it with the wire wheel. Turn on the angle grinder and slowly lower it to the sheet metal. This is the step where sparks will most likely fly. Use the wire wheel to take off the epoxy coating that may remain from the initial sanding. The wire wheel will remove the last remnants of epoxy coating and smooth the sheet metal. Make several passes over the sheet metal to ensure complete epoxy coating removal.