Water tank to Fuel tank

[Phil23]

I need to create additional fuel capacity and have a grp built in Potable water tank I can afford to sacrifice what is the practicality of converting this over what would be the suggested procedure ie draining sanitizing and preparing to fill with diesel

 

[FF]

Not all GRP is impervious to diesel. There would be some risk.


If the tank has no baffles perhaps a bladder installed would be rational solution.

 

[fgarriso]

Most GRP fuel tanks need to be seal coated to be safe with diesel fuel, and then pressure tested at 4-5 PSI