Black PVC is also very large and is certainly Not conducive for the stated purpose. Schedule 40 PVC 3/4" or 1" painted black is a good choice as it will allow a good flow of water still allow it to have time to heat depending on the length of the pipe. Using multiple U shapes will allow the water the best amount of time to heat. Hope this helps.
If you are worried about too much heat use CPVC which is designed for hot water but it is also a smaller inside diameter.
Raspberry Pi Class
What You'll Need & Learn
This is one I will have to try but on a regular bed so my dimensions will be different. I will just adapt to a smaller scale. I love the concept because I am an older person and the night lite sensor Idea will greatly benefit me.Thanks for a great "ible".
Welding Tools and Materials
Welcome to Welding
I notice this was posted a year ago yet I must ask a current and on going question????. The "dunks" used, are they harmful to bees? I am a beekeeper and most chemicals are not safe for use around my beehives. How about some of you chemical "experts" weighting in on the subject.