robtillaart:
How can i make sure a water tight cap is in place
step 1: Rewrite the problem as the solution
==> fill the system with water and if it leaks it is not in place.Step 2: make it realistic
==> fill it with air and if the pressure goes up the cap is in place, if not its not.Check - www.triz40.com - for pattern based problem solving (might be not the best site to start but OK)
Fair suggestions.
1: The air filled can is full of electronics, filling it with water each time i place the cap kind of defeats the purpose of needing to keep the water out.
2: We do a vacuum test to check the rest of the seals, but having a port that i can use to induce air means i have another hole to check and effectively doubles my problem. Then i would have to make sure two caps are in place.