Building a UDS, how do I know if a closed drum is unlined?
There is a steel shop near by that has 2 closed - unlined - food grade drums for $20 that previously had corn oil inside, he also stated there was no rust inhibitor on the inside.
How does he know this if it is closed? More importantly, how do I know this, is there some sort of mark I can check on the bottom of the drum or something?
I am trying to avoid a 4 hour drive to get a new one and a burnout as much as possible.