Freezing hot water pipes?

[Munch12]

serving the San Juans.

Hi infamos,

I am an old plumber in the high mountains of Colorado (Telluride) and water is my trade. I learned it from a "crawlspace perspective", starting in 1973. I have fixed thousands of broken pipes due to freezing and here is my take on why bare hot water pipes freeze quicker. It may be due to the condensation on the outside of the pipe (especially copper). Hot water running and then the condensation on the outside forms and freezes, then the pipe gets cold enough to freeze the water inside it. (As long as it isn't moving water). So, a hot water pipe does seem to freeze quicker when condensation is present. Another thing about hot water flowing in a pipe is that when it hits a 90-degree bend, a molecule of oxygen throws off and creates a tiny pinhole in the pipe, and hot water recirculating pumps are a culprit of pinhole leaks.

C:+o)