Checking the battery in a Cherokee

How often do you check the battery in your PA28? I don't remember ever
checking it except at annual. We just had paint and new interior done.
When the interior shop pulled the back seat they found where the battery had
overflowed and begun corroding. I wire brushed everything to bare metal
and sprayed some corrosionX on it. That should last until the annual and
we'll get a new battery box.

Side question; There is some expanded fiberglass insulation under the back
seat, next to both the port and starboard wing root rib. It looks like
standard construction insulation. The insulation on the starboard side had
absorbed some of the battery overflow so I threw it away. Am I going to die
because I just tossed some hypercritical piece of the airframe away? Does
anyone else have this insulation or did this come from a previous owner?
Anybody know specifically what the purpose of the insulation is (thermal,
sound, ???) ?

Thanks in advance,

Eddie
N40008

I hope that you didn't use a steel wire brush to strip the corrosion. The
steel wires of the brush embed into the aluminum and the dis-semilar metals
start electrolysis (corrosion). No matter what kind of paint or chromate you
use won't get the steel bits out and the metal will corrode under the
treatment. Ever wonder why some simple things associated with an aircraft
require an A&P's knowledge to do correctly? AC 43.13-1B addresses the
correct treatment very well. R Little

"nobody" wrote in message
. ..
How often do you check the battery in your PA28? I don't remember ever
checking it except at annual. We just had paint and new interior done.
When the interior shop pulled the back seat they found where the battery
had overflowed and begun corroding. I wire brushed everything to bare
metal and sprayed some corrosionX on it. That should last until the
annual and we'll get a new battery box.

Side question; There is some expanded fiberglass insulation under the back
seat, next to both the port and starboard wing root rib. It looks like
standard construction insulation. The insulation on the starboard side
had absorbed some of the battery overflow so I threw it away. Am I going
to die because I just tossed some hypercritical piece of the airframe
away? Does anyone else have this insulation or did this come from a
previous owner? Anybody know specifically what the purpose of the
insulation is (thermal, sound, ???) ?

Thanks in advance,

Eddie
N40008

On Wed, 04 May 2005 03:10:35 GMT, "nobody" wrote:

How often do you check the battery in your PA28? I don't remember ever
checking it except at annual. We just had paint and new interior done.
When the interior shop pulled the back seat they found where the battery had
overflowed and begun corroding. I wire brushed everything to bare metal
and sprayed some corrosionX on it. That should last until the annual and
we'll get a new battery box.

Side question; There is some expanded fiberglass insulation under the back
seat, next to both the port and starboard wing root rib. It looks like
standard construction insulation. The insulation on the starboard side had
absorbed some of the battery overflow so I threw it away. Am I going to die
because I just tossed some hypercritical piece of the airframe away? Does
anyone else have this insulation or did this come from a previous owner?
Anybody know specifically what the purpose of the insulation is (thermal,
sound, ???) ?

Thanks in advance,

Eddie
N40008


Hi Eddie,

I suspect it was added by a previous owner. My PA28-180 is bare under
the back seat.

The first time I lifed the back seat bottom, I did find two pieces of
foam rubber cut into 3x3 square tubes under the front edge of the back
seat. And it was clear from their cuts/shape that they had been
amateurly cut.

Whether the previous owner had them there to lift the front edge of
the seat, cushion the bounce a bit, or seal up the air flow at that
point (he had duct taped all the 'lightener' openings in the frame
members) -- I don't know. It may well have been air control since
this plane used to be up in Mass. But the foam was definitely added
by a previous owner -- not the factory.


Chuck
N7398W PA28-180

"Robert Little" wrote in message
...
I hope that you didn't use a steel wire brush to strip the corrosion. The
steel wires of the brush embed into the aluminum and the dis-semilar
metals
start electrolysis (corrosion). No matter what kind of paint or chromate
you
use won't get the steel bits out and the metal will corrode under the
treatment. Ever wonder why some simple things associated with an aircraft
require an A&P's knowledge to do correctly? AC 43.13-1B addresses the
correct treatment very well. R Little

Same for steel wool.


"nobody" wrote in message
. ..
How often do you check the battery in your PA28? I don't remember ever
checking it except at annual. We just had paint and new interior done.
When the interior shop pulled the back seat they found where the battery
had overflowed and begun corroding. I wire brushed everything to bare
metal and sprayed some corrosionX on it. That should last until the
annual and we'll get a new battery box.

Side question; There is some expanded fiberglass insulation under the
back
seat, next to both the port and starboard wing root rib. It looks like
standard construction insulation. The insulation on the starboard side
had absorbed some of the battery overflow so I threw it away. Am I
going
to die because I just tossed some hypercritical piece of the airframe
away? Does anyone else have this insulation or did this come from a
previous owner? Anybody know specifically what the purpose of the
insulation is (thermal, sound, ???) ?

Thanks in advance,

Eddie
N40008

nobody wrote:
How often do you check the battery in your PA28? I don't remember ever
checking it except at annual. We just had paint and new interior done.
When the interior shop pulled the back seat they found where the battery had
overflowed and begun corroding. I wire brushed everything to bare metal
and sprayed some corrosionX on it. That should last until the annual and
we'll get a new battery box.

IIRC from the PA28-180 I used to own, the battery box had some specific features
to contain any overflow and vent it to the outside airstream. I can't tell from
your posting whether the overflow got outside the battery box, but if it did,
your battery box isn't doing its job. Oh, I guess if it got on some insulation,
it must be outside the battery box.

Also, experts will correct me as required, but I don't think overflow should
happen in normal operation. Overflow means either that someone overfilled the
battery, or your charging system is overzealous.


Side question; There is some expanded fiberglass insulation under the back
seat, next to both the port and starboard wing root rib. It looks like
standard construction insulation. The insulation on the starboard side had
absorbed some of the battery overflow so I threw it away. Am I going to die
because I just tossed some hypercritical piece of the airframe away? Does
anyone else have this insulation or did this come from a previous owner?
Anybody know specifically what the purpose of the insulation is (thermal,
sound, ???) ?

The insulation is likely there to attempt to seal up some air leaks, which seems
to be a losing battle in these airframes.

Dave

Eddie, you can get a lot of really helpful advice from the Cherokee
Pilot's Assn - consider joining it.

I don't normally check the battery myself except for annual since it's
a sealed battery. If yours is a wet cell with caps, the fluid level
should be checked monthly and refilled with distilled water. There's
supposed to be a drain at the bottom of the box. And many owners who
fly up north add padding/insulation to cut down airflow from the back.
The PA28 door seals are poor, and air flows out through the door and in
from the back of the plane.

You can also find a lot of useful information on getting a good door
fit on the CPA chat site.

snip
I hope that you didn't use a steel wire brush to strip the corrosion. The
steel wires of the brush embed into the aluminum and the dis-semilar metals
start electrolysis (corrosion).
snip

I used a flexible, aluminum oxide coated, nylon abrasive wheel for most of
it. I did use a brass wire brush for some of the nooks and crannies around
the box itself. Brass is a dissimilar metal, does it cause the same problem
as steel?

Eddie
N40008

Also, experts will correct me as required, but I don't think overflow
should
happen in normal operation. Overflow means either that someone overfilled
the
battery, or your charging system is overzealous.

My partner and I had to jump start it twice this winter. I think that's
when it happened.

Eddie
N40008

The shop that does my annual repaints the battery box every annual. I'm
not sure why, my battery has never leaks. Its either preventative or
just an extra annual tax.

-Robert

The first time I lifed the back seat bottom, I did find two pieces of
foam rubber cut into 3x3 square tubes under the front edge of the back
seat. And it was clear from their cuts/shape that they had been
amateurly cut.

That's a standard, very effective (and often over-looked) cold-weather air
sealing technique.

When it's below zero, that foam can make all the difference between comfort
and agony, in the back seat.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"