[Daves55Sedan]

Somewhere back around 1997, I dismantled my '55 Courier wagon and took it down to a metal cleaning establishment in pieces. They used a giant chemical dunk-tank which strips all old paint and rust off of metal.
I had my hood hinges with everything else, but the guy there told me that the chemical would ruin the springs (make them brittle and cause them to crack). I held them back and stripped them myself with paint remover. The same principal applies to anything made of spring-steel (such as rear leaf springs).
An alternative to cleaning them would have been sandblasting or plastic-bead blasting.
I cannot imagine anything else that would break those hood hinge coil springs.