I need some help with welding the grub screws on my car.
I want to welding the grub screws on the battery tray to hold the battery to stop the battery tray to being move about on the road surface. There are two grub screws that are missing due to bad rusty on the chassis so I had the work done by a garage to repaired the damaged.
Here is the picture of the battery tray:
Here is the grub screw that I have got which it is the same type as the other grub screws that I want to weld it:
I have asked the garage if they could be able to weld it, but they didn't want to do it as they don't understand why I wanted them to do it and they was laughed when I asked them to do so they are stupid. I want to do it myself to get the work done to avoid the two other grub screws that I have already got on my car as I don't want them to get snap by the road surface, but there are few problems that I have got.
If I do it, it will get too hot and the metal parts would melt which I don't want that. And I dont know where to put the earth on my car to get it to welding.
Do you know how I could weld it to do it in a proper way to be safe without melt the metal that I had the work done already by someone else?
What is lower volts I should use to avoid the metal to be melt while I weld it?
If that is not possible, do I have to do it slowly to do it once at a time while seals on the metal to hold it in place?
And do you know where do I need to put the earth for the welding plug on my car when I remove the battery so I could be able to weld it?