Propane tank repurpose

Hello to all.  I have come into a 100-gallon propane tank that is like new but used.  Trying to figure out how I might use it on my sheep farm.  Any ideas?  Is there any way to sanitize these tanks and use them for water- even non-drinking water?

I've seen ads for wood stoves made from 20-30 lb. propane tanks. They would be suitable for heating ice fishing shacks or outbuildings. A 100 pounder would make a great stove.

Cutting it lengthwise would create a couple of feed troughs.

I think the inside of a propane tank is uncoated steel, so use as a water tank would lead to a lot of rust and corrosion. Some people pour in an epoxy paint and shake it around.

A compressed air tank is sometimes suggested, but I'm not sure. Propane vapour is very low pressure, so I don't know how much the tank could take.

FWIW, I think an expired tank still has cash value. People buy and recertify them.

Douglas, thank you.  Aside from epoxy, would there be any other way to make the tank sanitary enough for wash water?  I mean, is it the case that once propane gets into the pore of the steel there is no removing it?  And yes, I know these things have some cash value used- but don't ask me how I know, lol.  I also like the idea of a wood burner if there be no possibility for wash water.

The unprotected steel will rust. If you're using it for wash water in a shop, maybe that's not an issue. If you're piping it into a pressure system for a residence, it will stain sinks, clothing, you name it.

There won't be any residual contamination from the propane, although there may be a few drops of oil. Dish soap and warm water will cure that.

Theoretically, after using the tank for a while, the interior could be treated with a rust converter like phosophoric acid. The sheen of rust would be converted to a different form of iron oxide that is more stable. I haven't done this, so I don't know if it would work inside a tank.