Originally Posted by PaulC
Also, forgot to mention one thing. The rubber stopper I have for my erlenmeyer flask just would not stay seated in the flask. It kept pushing out no matter what I did.
Do you perchance have the plastic stem stuck all the way through the drilled plug? If you do this it wont let the rubber have the play it needs to stay in the hole. I just put the stem of the airlock in about half an inch.