2 stage rocket live test

Thought I'd better test this out before flying. Hand held the elastic band holding the cover down and pumped it up to just 30psi. Seems to work fine. Another bottle in the neighbours yard. Bit nervous about higher pressures. Will make a couple more variations on the idea so there's a Plan B on launch day.

After some sage advice from Air Command, i have decided to remake the whole system again without a non-return valve and just a small hole in the tube which will act as a pressure safety vent if launch is aborted. Thanks for the idea George.

here's vid of the test. Launching for real in January when i get back from Chrissy holidays.
Clear skies to all.