MIG Spot welding troubles

[WisetonMikey]

Hi Chaps, I've been using a Clarke edge joldler/hole puncher to plug weld my resto project. Sill work etc. joining 1mm thickness together. The trouble is that to get the plug to penetrate and therefore "stick", I'm having to drill out the hole to about 10mm. I'm keeping the power setttings and wire speed the same as normal. The hole is about 4mm. Is the problem with the tool or am I missing something? Mikey

 

[malcolm]

4mm is far too small. I'd go for between 6.5mm and 7mm holes for 1mm sheet. Trick is to start the weld on the sheet behind and let it flow by itself into the sheet above to ensure penetration. Maybe with a little circle at the end to prevent burning away the top sheet.

With a 4mm hole you'll be making "MIG spot welding" more easy rather than actually plug welding. Trick for that would be to turn up the power and wire speed, ensure good contact between sheets, and to some extent hope for the best. I've used the technique in emergencies when I've attached a panel and forgotten to drill the odd hole, but it's fickle.

 

[WisetonMikey]

Thanks Malcolm, I've now read the plug welding guide and can see the errors of my ways! Regards Mike