Cutting spot welds, gotta start somewhere :) Options

[bryanthompson]

I started on my 914 project and decided to do the trunk first. So, i started chipping away bondo from the inside of the bottom of the trunk and found (suprise!) more rust than expected. So, the bottom part of my trunk pan has to be replaced.

Anyway, i bought a spot weld cutter yesterday, but something about it makes me wonder. The tool looks just like this:
(IMG:http://www.ingallseng.com/graphics/Prodcut_Pictures/92900.jpg)
So, should i trim down the spikey thing or let it go through the whole car? I realize i'll be welding it back up so it wouldn't be the worst thing in the world if it made a hole, but what i'm worried about is the bending effect putting that much force will have... like i'll end up with little pimples around the hole left by the spike (not the saw part).
(IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/monkeydance.gif)