Hi, Steve,
Look kinda similar to the differential corrosion deposits you see on
oxidised aluminium, especially in moist weather. Although your storage
atmosphere may not be controlled, have conditions in it changed much from
normal - e.g temperature, humidity, specific storage location? Have they
been stored this time near any powered-up equipment that produced much of
an electro-magnetic field? That might set up a battery effect between the
conductive paint, the cadmium and the aluminium?
Have you tried brushing off any of the deposits to see if there is paint or
plating damage underneath? Much of the thread appears to have been
protected by the cover you mentioned, but there is evidence of some further
corrosion on a couple of threads high up underneath the cover. Do the
connectors carry date codes? It may be you've got a duff batch of
connectors where the paint or the plating or both have suffered from bad
application process, since the damage looks general.
Out of ideas, now, having clutched at a few straws.
Best of luck
Peter
Steve Gregory <[log in to unmask]> 08/02/2003 08:34 AM
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Please respond to "TechNet E-Mail Forum."; Please respond to SteveZeva
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cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST Aero/ST Group)
Subject: [TN] Substance on connector...
Hi all!
This is a late Friday post, and don't expect much response until Monday...
But the situation is that we build some back-up battery drawers that are
used on Naval ships...we've been building them for years.
We buy the chassis quite ahead of time, and store them inside their
shipping boxes (they're made of plywood and pine), and are stored inside
out of the weather, but not in a controlled environment.
There's a Cadmium plated, aluminum connector on the chassis, that is
painted with a olive drab, conductive paint (it's a mil-spec paint, that
has always been used). The chassis is made of brushed aluminum.
We got our batch of chassis for our latest build (they've been in storage
the better part of a year), and when we opened the boxes, we found all the
connectors covered with this white powdery substance. Go to:
http://www.stevezeva.homestead.com and look at "battery drawer connector".
You will see what I'm talking about. There's a screw type cover that goes
over the end of the connector, and there isn't any of the white substance
there. So that makes me think that whatever caused this, has to be airborn.
We've never seen this before in all the years that we've been building
them, that's why we're so puzzled.
We're going to get this analyzed to be sure, to try and find out what this
is, but wondering if anybody else has seen this before...
Thanks!
-Steve Gregory-
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