I’m the OP.
I took another look at the “ding” on the tank that U-Haul complained about. I think it would more properly be described as chipped paint than a dent or damage. Then it rusted a little where it chipped. There are small impressions less than the size of the head of a pin. Maybe it was set down on a rock at some point.
The lesson learned might be to inspect the tanks after each camping trip and use some touch up paint on any chipped paint.
However, the U-Haul website says “If a propane tank is uncertified, damaged... excessive rust or ***has been painted*** violates national propane gas rules and policies and will not be refilled.”. So it is unclear if touch up paint will get you grief when trying to refill.
I have gotten tanks from cylinder exchange for the BBQ in vastly worse shape than these tanks. Tanks with paint over rust then the paint chips so the tank is covered in rust.
(I am surprised that some responses said they use cylinder exchange. I have always assumed that I should use tanks that I have owned since new so that I know they have been carefully handled. Which can be a pain because propane refill can be harder to find than exchange. Maybe for a trailer where the tanks are outside, but in my truck camper I sleep literally a few feet from the propane tanks so I am hesitant to trust propane exchange.)
I am sure that my tanks are ok. On the other hand, I looked it up and the local U-Haul sells new tanks for $35, so for $70 I can have two new tanks and not worry about it. I’ll probably do that.
Thank you for the help! I was getting nowhere with google searches about this topic.
