Sorry for the late reply to your question Geo. The key to cutting the aluminum tape is to not only use a new blade, as you have done, but to also cut the tape in several very light passes. Use a straight edge and just scratch the surface on your first pass, then go a little harder and keep progressing until you've smoothly cut through the metal. If the tape buckles, you are pressing too hard. I'm guessing about 5 swipes are needed and I do not add any more glue than what is on the tape; the glue on the tape I use is quite tacky and has so far been sufficient for my needs.