When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The weld example shown above was done with a TIG welder and was only used to show the stacking affect as it is a nice clear example.
I believe that was done using a "pulse arc". That feature is on a lot of the higher end TIG welders and is also available on some high end mig welders as well.