i just use cheap primer,red oxide. i primered fenders that were sandblasted and they sat 5months in a damp garage and they look great.
for a story on contents of soda, when i hauled over the road i used to haul chemicals to make coke,some nasty stuff, had a 53' trailer all i can carry is 2 fifty five gallon drums in very front,secured well.1 20 gallon drum in the middle,secured well, and 2 1'x1' square boxes at the back doors. from new york to california hazardous placards on trailer,while getting loaded you sat in truck with 2 armed guards watching you.