Degaussing a Warrior

Has anyone reading this group had to degauss a firewall? My Warrior
took a lightning strike last July while parked, melting a bit of the
propeller tip and magnetizing much of the plane forward of the firewall
(so that the compass always points towards the propeller). The engine
has now been overhauled, and all engine parts and the mount degaussed,
but after trying several compasses, we cannot get any to indicate
properly -- something is still strongly magnetized. Tomorrow my AME
(IA/A&P) will bring in a specialized meter and degaussing device to
start trying to hunt down the problem, but I'm quite discouraged being
grounded for this long.


Thanks in advance for any help,


David

In a previous article, "DavidM" said:
(so that the compass always points towards the propeller). The engine
has now been overhauled, and all engine parts and the mount degaussed,
but after trying several compasses, we cannot get any to indicate
properly -- something is still strongly magnetized. Tomorrow my AME

Aw man, you can't catch a break, can you? I thought you were ready to
start flying again.


--
Paul Tomblin http://xcski.com/blogs/pt/
Could you stop changing your email address willy-nilly, so my killfile
can spare me from your erudition and wit?
-- Alan Shutko

DavidM wrote:
Has anyone reading this group had to degauss a firewall? My Warrior
took a lightning strike last July while parked, melting a bit of the
propeller tip and magnetizing much of the plane forward of the firewall
(so that the compass always points towards the propeller). The engine
has now been overhauled, and all engine parts and the mount degaussed,
but after trying several compasses, we cannot get any to indicate
properly -- something is still strongly magnetized. Tomorrow my AME
(IA/A&P) will bring in a specialized meter and degaussing device to
start trying to hunt down the problem, but I'm quite discouraged being
grounded for this long.


Thanks in advance for any help,


David

This is probably stating the obvious, but only the iron/steel stuff
can be magnetized.

A dime store (do those exist anymore?) compass should point to the
magnetized part as you walk around the nose.

Held too closely it will point to any iron/steel part magnetized
or not, so start out at a distance where you start seeing a "disturbance
in the force".

--
Jim Pennino

Remove .spam.sux to reply.

You might check

http://www.sacskyranch.com/degaussi.htm

Your firewall is galvanized steel (not stainless steel) as I recall.
It is probably the culprit.

wrote:

Held too closely it will point to any iron/steel part magnetized
or not, so start out at a distance where you start seeing a "disturbance
in the force".

We've done the compass walkaround in great detail, and as best we can
tell, the remaining problem is close to the firewall (the engine mount
was already degaussed in Halifax while the engine was being
overhauled), though there are one or two other minor hotspots. A
proper meter (I'm not sure whether it's a "gauss meter" or a "flux
meter") will be arriving at the shop tomorrow, and that should let us
pinpoint the problem more closely.


All the best,


David

Maybe you should just give up and get a vertical card compass with a
remote sensor out in a wing tip.

Has anyone reading this group had to degauss a firewall? My Warrior
took a lightning strike last July while parked, melting a bit of the
propeller tip and magnetizing much of the plane forward of the firewall
(so that the compass always points towards the propeller). The engine
has now been overhauled, and all engine parts and the mount degaussed,
but after trying several compasses, we cannot get any to indicate
properly -- something is still strongly magnetized. Tomorrow my AME
(IA/A&P) will bring in a specialized meter and degaussing device to
start trying to hunt down the problem, but I'm quite discouraged being
grounded for this long.


Thanks in advance for any help,


David

Drew Dalgleish wrote:

Maybe you should just give up and get a vertical card compass with a
remote sensor out in a wing tip.

Using a remote sensor (probably in the tail rather than the wingtip) is
my fallback, if everything else fails. I'm not sure whether an STC
would be required for that.


All the best,


David

WIth the flux meter and a Color TV degausser coil, you should be able
to cure it... Even a compass will help you pick out the magnetized
areas in the engine compartment for giving the buzz treatment... The
key to using the degausser is to buzz the part and keep the power on
while you withdraw the coil, not put the coil against it and just turn
the power on and off...

denny

Denny wrote:
: WIth the flux meter and a Color TV degausser coil, you should be able
: to cure it... Even a compass will help you pick out the magnetized
: areas in the engine compartment for giving the buzz treatment... The
: key to using the degausser is to buzz the part and keep the power on
: while you withdraw the coil, not put the coil against it and just turn
: the power on and off...

I'll agree that the tv degausser will likely be able to do it. With all the
decorations (like engine mount + engine), it might be tricky to get in where you need
it to be.

I'd recommend removing any/all things possible to reduce the risk of
magnetizing anything else.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

Denny wrote:
: key to using the degausser is to buzz the part and keep the power on
: while you withdraw the coil, not put the coil against it and just turn
: the power on and off...

Oh, and if space constraints make it difficult or impossible to gracefully
move away while running, you can probably use a variac to ramp the field up/down to
simulate moving the coil. That's how the degaussers in monitors work.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************