John Fenner showed us his home-made stud welding solution in a Project Journal entry some time back:
http://forum.britishv8.org/read.php?13,15518 John's solution used a 12V battery, battery cables, and a Ford-style starter solenoid. To grip and pull the installed studs, he used parts from a gutted pneumatic pop-riveter to which he attached a slide-hammer.
Have you tried something like this? Thought about it maybe? Please share your tips and ideas.
I'm also interested to hear your thoughts about building a battery-powered spot welder.
Here is a good resource for DIY homemade tools:
http://www.homemadetools.net/site/search?q=spot+welder&Search=
HomemadeTools.net admin checking in. Thanks for the kind words :)
Try our "spot welder" tag: spot welder tools (http://www.homemadetools.net/tag/spot-welder)
BTW we've got a couple of homemade tools from BritishV8.org listed on our site: Homemade tools from BritishV8.org (http://www.homemadetools.net/sites/britishv8.org) (James Bowler's Hammerforming Setup and Bill Young's Rotisserie). If we've missed any that you'd like to get listed, let me know and I'll get them added. We always fully credit the original builder and forum, and link back to the originating post.