Thanks for all the suggestions. A little more explanation may help. The decals are not the same as the ones you normally find with a model car or airplane. In other words, you don't dip them in water then slide them onto the "model". These were rub on stickers that were on a piece of paper, rub over the decal and it lets loose of the paper and attaches to tube. Perhaps I didn't rub it on thoroughly. It could have been the oil from fingers lifting the ends of the flame.
I like the idea of spraying it with something first. I'll have to try that next time.
As far as catalyst, I don't think I used too much. If anything, I used too little as it took over a week to harden and I had to cut it out of the mold. I used the Wal-Mart ice cube trays.
Thanks for the comments. I hae some red flames left over. I'll have to try another.
By the way, my customer bought this pen. They were very happy with it as it was, regardless of the problems.