Some inexperienced people may notice that the electrode keeps sticking on the sheet material that they are trying to spot weld. That phenomenon is the result of some mistakes that could have been made prior to the commencement of the welding operation. This article discusses some of the things you can do to make sure that electrode sticking doesn't occur as you weld.
Align Electrodes Well
The electrodes that you connect to the sheet material before you start the process of resistance spot welding must be properly aligned so that the current can flow uniformly through the material. Any misalignment can result in electrode sticking. Check and confirm that you are using tips of the appropriate size. Align them correctly on the material before you start spot welding.
Replace Contaminated Tips
The electrode tips that you are using also merit an inspection to check if they are contaminated. Contamination is likely to occur if you used those same tips to spot weld a galvanised metal. The zinc which collects on the tip can initiate overheating on that surface. This can result in electrode sticking. Replace the tip if you see high amounts of contamination on it.
Adjust the Electrode Force
Electrode sticking can also take place if the electrode force which you have selected for a give spot welding task is too low for that application. Check the manual of your spot welding equipment and find out the correct magnitude of the welding force. Make sure that you use the right squeeze time so that the recommended weld force is attained prior to the flow of the welding current.
Clean the Material
The sheet material, such as stainless steel, also needs to be clean before spot welding is attempted. Contaminants, such as grease or oil, can cause the surface of the material to heat up excessively during spot welding. That excessive heat causes the electrode to stick onto the material. Some surface treatments, such as passivation (stainless steel treatment to reduce the chromium oxide layer) can also cause electrode sticking. Confirm this possibility by test welding a part whose surface has been abraded and compare the results. Adjust the sheet material based on your findings from that test.
The adjustments above are usually sufficient to correct most cases of electrode sticking during spot welding projects. Get expert help in case you don't see any change after you have implemented the changes that have been suggested.