Spotwelders

[shoddy_f-body]

Hate to tell you but that thing will not produce welds strong enough to hold a car together. You need to have about 10,000 amps at the electrodes and 900 pounds of squeeze pressure to make a good strong spotweld. A hundred dollar toy like that aint going to cut it. If you want to test it,Weld two pieces of overlapping metal at 90 degrees from each other so they form a L. Spot weld the metal together, once cool clamp one end in a vice and twist the other end off. It WILL rip a hole in one of the pieces of metal if welded properly. Measure the dia of the hole should be greater then or equal to 3/16" according to ICAR welding specs.I can tell by the pictures your not getting good penetration. I used a Snap On spot welder that was about $4000 and it was hit or miss whether the welds would hold or pop loose after a little while. We have a Pro Spot brand spot welder at my shop that IS designed for spot welding replacement panels on vehicles and is approved by the OEM's. It works great but cost was about $20,000.Not trying to be a jerk,just dont want to see you have problems down the line.

http://www.prospot.com/