Peerless corrosion??

JayMX
JayMX Posts: 446
in Vintage Speakers
So I picked up a pair of really clean Monitor 4’s today for a song. They were missing one MW6500 but I had some spare 6502’s that I loaded in them for testing. They sound great, but while cleaning them up I popped the drivers and I find this white stuff on the backs of the tweeters. It’s all over the magnets and backplanes. It was actually coming out around the screw holes as well. Flakes off when scrubbed, doesn’t burn the flesh like battery acid... :D It doesn’t show up anywhere else in the cabinets. Thoughts? What is it?
zfvbje3xopk6.jpeg
zsvrnkuc9phi.jpeg
25t4wxldsxax.jpeg
Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (4x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
· Share on FacebookShare on Twitter

Comments

  • F1nut
    F1nut Posts: 50,544
    Mortite gone bad.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

    · Share on FacebookShare on Twitter
  • JayMX
    JayMX Posts: 446
    F1nut wrote: »
    Mortite gone bad.
    These have regular gasket material like I’ve seen in other cabinets. Isn’t Moretite usually found squished between the drivers and the MDF? Was it employed in conjunction with the closed cell foam gaskets? This stuff reminds me of battery acid corrosion, minus the burn. Or maybe salt, I didn’t dare taste it though...
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (4x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
    · Share on FacebookShare on Twitter
  • xschop
    xschop Posts: 5,000
    SnO2
    Don't take experimental gene therapies from known eugenicists.
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,544
    JayMX wrote: »
    F1nut wrote: »
    Mortite gone bad.
    These have regular gasket material like I’ve seen in other cabinets. Isn’t Moretite usually found squished between the drivers and the MDF? Was it employed in conjunction with the closed cell foam gaskets? This stuff reminds me of battery acid corrosion, minus the burn. Or maybe salt, I didn’t dare taste it though...

    Just a guess. I've seen that multiple times, really not sure what it is.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,544
    xschop wrote: »
    SnO2

    That very well could be it, makes the most sense.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

    · Share on FacebookShare on Twitter
  • mlistens03
    mlistens03 Posts: 2,767
    I have a Kenwood woofer that has the same thing, but not nearly as bad. I believe it to be oxidation of some kind, but I really do not know.
    · Share on FacebookShare on Twitter
  • mhardy6647
    mhardy6647 Posts: 33,801
    Looks like it's beenin a very damp location for quite a while.
    Baltimore (or New England) basement?
    · Share on FacebookShare on Twitter
  • westmassguy
    westmassguy Posts: 6,850
    They're 4s and are ported, so good gaskets or no, moisture will get in. the front's should clean up nicely. A prescription bottle cap will cover the silk dome perfectly, allowing you to clean off the corrosion, lightly sand and then hit them with some Krylon. For the rear, a soft brass parts brush and some clear lacquer perhaps.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer

    dhsspeakerservice.com/
    · Share on FacebookShare on Twitter