Thank you for the reply to my predicament. I appreciate you taking time to reply.
The spot weld takes only a few nanoseconds and the surface of the weld/tab/battery end are not warm to the touch (i.e. when I first started making packs I checked out the temperatures of the batteries by practicing on old cells). I make all of my packs the same way and I have other packs (AA and AAA cells) wrapped in clear shrink wrap and they show no signs of leakage and hold a charge.
Hopefully you may have some other thoughts?
Cheers