Why do I need to seal the holes that I drilled into the bottom of a flower pot when making a small water fountain?

I don't think you should use a cast iron pan but it could work if you are desperate. I would definitely use a gas stove.

Combine flour, yeast and water, and mix them together.

Yes, especially if you are using the shuffleboard table in a basement. If you only seal one side, the other side will still be vulnerable to moisture in the air,...

In general, plans for construction may be available where supplies are purchased.

Use an electric drill with a masonry bit. Start slowly and increase speed and pressure as needed. Be patient.

It will work but you have to be very careful not to accidentally sand the sides of the pitcher with the sand paper as it will show extremely visible scratches....

It may be due to fear, and you might need to consider whether that's the best tool for them. Even though the fountain is recommended in many ways, if your...