Dimensions NEEDED

"Scott Derrick" wrote in message
...
I have a pusher airplane with a nose oil cooler.

I am replacing the existing heavy hydraulic type(rubber/braided steel)
oil cooler lines with lighter metal lines. Either soft Aluminum or soft
copper 1/2 lines.

I would NEVER use copper for an important thing like an oil line, on
anything that has a motor, and vibration. Copper will work harden from the
vibration, and fail. Not "if" but "when." It will happen, if there is any
possibility of flexing.
--
Jim in NC

I would NEVER use copper for an important thing like an oil line, on
anything that has a motor, and vibration. Copper will work harden from the
vibration, and fail. Not "if" but "when." It will happen, if there is any
possibility of flexing.


That's two things you shouldn never do. Copper lines and use any
fluid line as a ground.

"Don Hammer" wrote in message
news:1126039198.a572e3b81309f32dba604a668d4c9128@t eranews...


I would NEVER use copper for an important thing like an oil line, on
anything that has a motor, and vibration. Copper will work harden from
the
vibration, and fail. Not "if" but "when." It will happen, if there is
any
possibility of flexing.


That's two things you shouldn never do. Copper lines and use any
fluid line as a ground.

Yep. One reason is all would need, and either one of ours would do it.
--
Jim in NC

In article ,
Bashir Salamti wrote:

On Mon, 05 Sep 2005 17:48:06 -0700, Smitty Two

:
:I'm not disagreeing with anything that you or anyone else has said on
:this topic, but I will point out what appears to me to be a small hole
:in your logic. If the oil line were to develop a pin-hole -- as opposed
:to severing -- there might well be an "atomizing spray," but there won't
:be an arc, because, obviously, the electrical path would still be
:continuous.

I posted this elsewhere but somehow I think this thread is split in
two parts so I will again.

He's talking about using the tube as a ground. Imagine a small
positive wire, to a position light for example, rubs on it.
Eventually it rubs a small hole in the insulation, and creates a small
electrical arc to the grounding tube. The arc slowly erodes the
copper, like an EDM (Electric Discharge Machining) arc would.
Eventually you get that pinhole, spraying hot oil right into your
electric arc.

Think of what happens when you spray WD-40 into a cigarette lighter.
Kind of like that.


Ah, yes, now that I've reread the whole thread, I see my confusion. By
golly, you did originally speculate on the EDM concept. However, another
respondent, Mr. Bonomi, offered that if the line broke completely
through, there would be sparking across the gap. It was his scenario
that I was envisioning when I wrote the above. I guess there's more than
one way for an airplane to catch on fire.

Smitty Two wrote:

In article ,
Bashir Salamti wrote:

On Mon, 05 Sep 2005 17:48:06 -0700, Smitty Two

:
:I'm not disagreeing with anything that you or anyone else has said on
:this topic, but I will point out what appears to me to be a small hole
:in your logic. If the oil line were to develop a pin-hole -- as opposed
:to severing -- there might well be an "atomizing spray," but there won't
:be an arc, because, obviously, the electrical path would still be
:continuous.

I posted this elsewhere but somehow I think this thread is split in
two parts so I will again.

He's talking about using the tube as a ground. Imagine a small
positive wire, to a position light for example, rubs on it.
Eventually it rubs a small hole in the insulation, and creates a small
electrical arc to the grounding tube. The arc slowly erodes the
copper, like an EDM (Electric Discharge Machining) arc would.
Eventually you get that pinhole, spraying hot oil right into your
electric arc.

Think of what happens when you spray WD-40 into a cigarette lighter.
Kind of like that.


Ah, yes, now that I've reread the whole thread, I see my confusion. By
golly, you did originally speculate on the EDM concept. However, another
respondent, Mr. Bonomi, offered that if the line broke completely
through, there would be sparking across the gap. It was his scenario
that I was envisioning when I wrote the above. I guess there's more than
one way for an airplane to catch on fire.

Of course, if the line did not break completely, it would be a higher
resistance point which would get hot, just where the oil is coming out.


--

John Halpenny

Truth is stranger than fiction.
This is why writers and readers are more comfortable with fiction.