Comments on: How to Build a Pneumatics Training Board

on 9/30/2008 I reccomend using a hydraulic/gravity feed set-up. Use 1/8th inch tubing and drill a hole in the bottom of the container. Insert the tubing into the hole and use water proof glue to secure it. Cut a section i the tubing and install a simple on/off valve in the line. Use water proof glue to secure it in the feed line. Follow the same procedure for a container located slightly below the level of the pumice container. Fill the pumice container by turn the valve to the on position and off when all water is in the pumice container. After the pumice rocks have floated, open the valve to the lower container and drain the water out of the pumice container. Refill the top container and start the experiment again with the next student.

Thanks for the comment and the two stars. I was an educator for many years and I love to help teacher with projects like this.
Sincerely,
Paul

on 9/23/2008 I need to build a small, hands-on, table top science type project that will challenge children form 9 years old and up, to consider if a rock will float. At first look, this display will look like a couple rocks resting on the bottom of a dry clear plastic bowl. Question on a sign would read like, "Do you know if a rock will float?" Think about it. Once you decide, then push the RED button. When the RED button is pushed, water will gush into the bowl and fill it about half way. The rocks begin floating immediately since it is pumice. After about 10 to 15 seconds, the water in the bowl rapidly drains out leaving the rocks on the bottom of the empty bowl. System is now armed and ready for the next curious child. Please help. Is pneumatics and electrical switches the way to go? This is a tool I would like to build that will teach children some important information about rocks.