| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1089.1 | Black Wire Corrosion. | CTD024::TAVARES | John -- Stay low, keep moving | Wed Aug 23 1989 10:26 | 9 |
| Chuck, this is called "black wire corrosion", and has been
much discussed in the magazines over the last two years. The
answer is that nobody knows what causes it -- the best theory has
to do with the current in the wire reacting with the insulation
of the wire and causing the corrosion. The thing that makes it
hard to explain is that it generally only occurs around the
negative terminal on the battery (thus the name), but has also
been seen elsewhere in the circuit. The solution: keep an eye on
the wires and replace as necessary.
|
| 1089.2 | Copper and Tin don't mix | K::FISHER | Stop and Smell the Balsa! | Wed Aug 23 1989 12:26 | 24 |
| >Chuck, this is called "black wire corrosion", and has been
Maybe - but I'll bet it happened on both the negative and positive
terminals. Assuming this I believe what your seeing is common
corrosion caused by current flow through dissimilar metals. This is the
reason that you can make a battery out of a penny and nickel sandwiched
between some paper and spit.
Also this is the primary reason aluminum house wiring is illegal in
Massachusetts and most other states now. If you hook aluminum wire
to copper connectors they will corrode and cause high resistance and
heat and eventually possibly a fire.
Your alligator clips are most lightly made of copper and your battery
terminals are made of tin/lead alloy. If you solder a tin/lead
spade lug on the ends and bolt that to the battery connectors you will
never see the problem again.
Wonder what the cycle time is on those penny/nickel/spit batteries?
Bye --+--
Kay R. Fisher |
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| 1089.3 | Corrosion on both posts | GENRAL::BALDRIDGE | Now it's Summer!!! | Wed Aug 23 1989 13:18 | 6 |
| Kay, you're absolutely right! Corrosion on both alligator clips
which are tin/? plated copper. Ring lugs and bolts definately in
order.
Chuck
|
| 1089.4 | a galvanic couple | LEDS::LEWIS | | Wed Aug 23 1989 14:27 | 10 |
|
Yes, it sounds similar to a problem we had with one of
the disk drives our group was designing. We were grounding a copper
flex circuit to an aluminum chassis using a tin plated screw, and
the different metals form something called a "galvanic couple"
(just love that term!). Anyhow, we were getting corrosion and had
to add a ground lug made of compatible metals. Seems that your
solution should work fine.
Bill
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| 1089.5 | Grease it up!! | MAMTS1::BDONAGHY | | Thu Aug 31 1989 16:42 | 13 |
| Try using the ring lugs like you mentioned, make sure the posts
on the battery are real clean ( use some light sand paper or steel
wool- becareful of shorts-). After you attach the lugs and have
a good connection coat the terminal posts and any bare part of the
lug with vasoline or bearing lube or automotive lube . the corrosion
comes from oxidation which can only occur when air is exposed to
metal. The same thing happens to your car battery. I have used this
meathod for a long time mand it seems to work well.
Good Flying
Bob in Phila.
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| 1089.6 | corrosive fumes? | POBOX::KAPLOW | Set the WAYBACK machine for 1982 | Wed Oct 25 1989 11:56 | 5 |
| You didn't mention the type of battery you were using, but a
lead/acid battery gives off corrosive fumes and sometimes slop
acid around. That could be doing in your connections. Best bet is
the ring lugs and the jelly lubricant as you would do on a car
battery. Also make sure your battery compartment is vented.
|