On Sat, 02 Dec 2006 01:40:24 -0500, Larry wrote:

the PLASTIC in this little 4-pin plastic plug,
was so stressed, chemically, by the combination of atmosphere and 12VDC
it DISINTEGRATED into powder! I'd never seen anything like it in 42
years in electronics. The plastic between the disconnected data pins was
hardened, but not disintegrated.

Possibly UV damage? There are a lot of plastics that don't do well in
sunlight because of that.

Wayne.B wrote:
On Sat, 02 Dec 2006 01:40:24 -0500, Larry wrote:


the PLASTIC in this little 4-pin plastic plug,
was so stressed, chemically, by the combination of atmosphere and 12VDC
it DISINTEGRATED into powder! I'd never seen anything like it in 42
years in electronics. The plastic between the disconnected data pins was
hardened, but not disintegrated.


Possibly UV damage? There are a lot of plastics that don't do well in
sunlight because of that.

What about electrolysis of the unavoidable film of concentrated brine
(from salt crystals in the air + ordinary humidity) producing bleach and
chlorine, both of which degrade many plastics?

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Ian Malcolm wrote in
:

What about electrolysis of the unavoidable film of concentrated brine
(from salt crystals in the air + ordinary humidity) producing bleach and
chlorine, both of which degrade many plastics?



I'd believe that, and have seen it, but the powdering of the plastic was
deep down into the solid plastic plug, far away from its surface. The
plastic, itself, must be conductive and the tiny current the DC caused
through it broke down the plastic molecules is the only explanation I could
think of. The disintegration stopped right at the bottom to the metal pins
as I pulled the plug apart in my fingers...

Larry
--
If we eliminate religion, will they stop murdering each other?

Wayne.B wrote in
:

Possibly UV damage? There are a lot of plastics that don't do well in
sunlight because of that.




In the shade under the bimini. No sunlight direct.

The ONLY place where the plastic disintegrated is BETWEEN the +12VDC and
ground pins. The rest of the plug was untouched out of that path between
ONLY those metal pins, a track about 1/16" wide. The dead pins and the
plastic behind the exposed power pins was untouched by the devastation. It
points directly to 12V electrolysis between those pins.

Garmin needs different thermoplastic in their plug maker machine.

Larry
--
If we eliminate religion, will they stop murdering each other?