We were welding a .003" gold flashed nichrome wire to a .04"X .75" 301 SS strip. The electrode pressure, weld pulse lengths and electrode cleanliness had to be just right or the wire would blow away. I also have two of the transformer type spotwelders that are used for autobody work.
Based on this experience, I am well acquainted with subtleties of this powerful welding technique.
The need to weld battery cells into subpacks to repair hybrid batterypacks gave me a reason to build a good sized spotwelder, and since the cells needed to be welded with minimum heat effected zone,the very rapid high current pulse from a capacitor discharge welder is the best solution.
This blog describing the construction and development of the welder starts at the bottom of the page.