Ditto on the internal coatings. At best they take about a week of tumbling to remove and it may not be worth the effort unless the tank is otherwise in good condition.
The good news is that if the tank has had a recent hydro and VIP, the coating has probably long since blisterd and been removed. If it has not been hydro'd since the 80's it could be a problem.
The good news is that if the tank has had a recent hydro and VIP, the coating has probably long since blisterd and been removed. If it has not been hydro'd since the 80's it could be a problem.