Unhardened construction foam in one's inventory can be compressed into a cf pellet, and used to create 26 unhardened construction foam blocks (2 uses of a cf sprayer) in the world. Because these blocks don't drop anything, they can't be recovered to create 26 more cf pellets.
However, the silk touch enchantment guarantees that a mined block will drop itself, even if the block wouldn't normally drop anything. Since I can't seem to get any luck getting my picks silk touch, I pose the question: am I right? Can silk touch be used to create a near-infinite supply of construction foam, by compressing it into cf pellets and spraying it again?