A fella just stopped by my office and said he has 2 barrels, they have been around his house for 20yrs, they are sealed type with the little 3" screw tops? He said I had to take both....do you folks think it is safe? Can a fire burn out most of the bad stuff? What about the sealed top, you would think there would be some way to get that top off. any help would be greatly appreciated, I am itchin' to make one of these things.