Oh man - usually once it starts to go, it goes but it depends on where and to what degree it's popped. You may have better luck cutting it and melting the top sheet back (that's what we do). The other option is using epoxy and d clamps to really get it snug. That's what we do when boards or skis start to delam at the toes. If it's near the sidewall, we cut it back and melt it.
Do you have a picture?
Do you have a picture?