I have some TM-500 plugins that have been stored for a number of years in the garage in what I thought was a safe plastic storage container that is almost fully sealed from the atmosphere. To my horror when opening the box on the weekend all plugins have suffered some amount of corrosion damage. Examples of the damage include hardware items such as screws rusting, aluminium oxidisation and plastic (typically inner cables) showing chemical deposits on the outer surfaces. A couple of the plugins were fully wrapped in bubble wrap and have also suffered damage.
I had wondered if moisture had got inside the container which is possible given that a small amount of air would be able to get insider the container around the opening however given the nature of the damage this does not seem to add up.
My suspicion is that the foam inside the container has emitted some sort of chemical that has caused the corrosion possibly Methylene Chloride which is apparently used in the production of polyurethane foams. Would this make sense or is something else the likely cause of the issue?
