Most of my 3 piece airlocks are 30+ years old. The plastic may be slightly cloudy on a few, but they are solid. I've noticed that folks tend to prefer one or the other ... and they both do the job.
I solved the problem with the vented bungs -- tough love. Push them in firmly and if they pop up a bit, push 'em again. Repeat until the bung gives us and stays in place.
I solved the problem with the vented bungs -- tough love. Push them in firmly and if they pop up a bit, push 'em again. Repeat until the bung gives us and stays in place.