Mesa Boogie DC-3 flight case acetic acid corrosion oxidation

[xtian]

I received a Mesa Boogie DC-3, supposedly mint, in a nice looking flight case (possibly A&S Case brand?). Owner said it had been in storage for years. As soon as I opened the case, I got strong whiff of vinegar (acetic acid) and I found heavy corrosion on steel parts (but not the stanless parts) and some solder joints.

Is this common? Could the foam in the flight case have offgassed?

The amp is non-op; no sound from power section, though preamp is sending intermittent sound out thru Slave jack. Many interruptions in the signal chain, even after cleaning the pots.

[g1]

Maybe the foam was attached with silicone sealant?

[Purgasound]

That comes from moisture. A storage unit or basement is not a dry environment and without desiccants this will be the outcome.
Best to clean all jacks and tube sockets with Deoxit before powering on. Should be fine.

[Leo_Gnardo]

Is this common? Could the foam in the flight case have offgassed?

Yes, and definitely. On occasion I've had to deal with amps that have been clapped inside ATA cases since yonks. Worst case was a nice brown Fender Vibrolux I had brought up to snuff for a client, then he put it in the roadcase 20+ years. I don't think it would matter much what the external environment was, foam padding deteriorates and emits corrosive gas. No problem when amps etc. are on tour, opened every day for an air-out, seldom left for more than a few days whilst being transported long distance or stored while the band takes a week or two rest. This poor VLux, it was near mint when I worked on it decades ago, and sadly corrosion worked its misery on all the metal surfaces, now showing rust on steel, and thick crud on non ferrous parts. Surprisingly, cleaning pots, tube sockets & pins, cleaning jacks & speaker plug was all it needed to work right, BUT the looks certainly suffered. Some foams emit acetic acid - you can smell it. Others, it seems like some sulfurous gas comes out instead. Best policy, DO NOT STORE GEAR LONG TERM IN ROAD CASES.

[Mick Bailey]

The foam may be EVA - ethylene-vinyl acetate. This breaks down to release acetic acid and can ruin equipment very quickly.