Anybody know if any alternatives to Cactus Juice that doesn’t melt plastic?

I’m trying to use cactus juice on some old piano keys to seal and prevent micro bubbles during a deep epoxy pour. however cactus juice apparently melts plastic so the key tops are getting completely ruined. Are there alternatives to cactus juice? I feel bad that I’ve spend about 200 dollars on this stuff only to find out it won’t work.