After I take my radiator out... how long can it sit without fluid in it before it goes bad? I was told that they eventually dry-rot.

 

Well. dry rot occurs in wood. What can happen is rust. water and metal do not mix. the best thing you can do is flush it and blow compressed air in side to dry it as best as possible. After that, store it away from moisture for as long as you want.

 

Alright, thanks.

 

I believe it'll still rust even after you blow it out with air, it'll just rust much, much slower. Depends how long you want to store it.