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Ok - the tube I'm soaking is coming along nicely. The faceplate (but not the tube!) cracked (mechanical stresses from the clothespins being a bit enthusiastically applied), and I pulled most of the pieces off. The remainder is soaking, but water seems to make slow but sure inroads into it.
What the heck is this stuff? After soaking, at ambient temperature (55-60 degrees, it's very brittle and not exactly clear. I'm guessing water leeched out the plasticizers from it. It's about 1/16th inch thick. Along the sheets of stuff I've broken off, they're pockmarked with areas where it decayed in advance.
What causes the decay? Possible hint:This tube came from a water-damaged box. Moisture ingress? But that doesn't explain the decay towards the center. Maybe it's an unstable compound - but I've got two RCA tubes that show virtually no sign of delamination (I think this tube's an RCA, too).
Everyone calls it PVA - have we gotten a confirmation that it actually *is* PVA?
Oh yeah, it burns really sooty and is pretty self sustaining once it gets going. Heat softens it up a lot. I tried acetone - no effect.
Is this stuff perhaps really a silicone of some sort? RTV, maybe?
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