I knew I left something out! If you're replacing pouches that have
a cardboard lifter disc attached to them, don't  seal the entire pouch.
Leave a tiny area in the center of the pouch unsealed by the thinned
rubber cement mixture. This is where the drop of glue that holds the
lifter disc to the pouch will go. When attaching the lifter discs, it's
best to inflate each pouch by means of a short length of tubing attached
to the pouch input nipple. With the pouch inflated, it's easier to center
lifter disc. I hope that this helps!

Les Smith