Today's Message Index:
----------------------
1. 06:38 AM - Insulated ground cables? (David Saylor)
2. 07:38 AM - Re: Insulated ground cables? (Charlie England)
3. 07:40 AM - =?utf-8?Q?Re:__Insulated_ground_cables=3F? ()
4. 08:34 AM - Re: Insulated ground cables? (David Saylor)
5. 08:43 AM - Re: Insulated ground cables? (David Saylor)
6. 09:06 AM - Re: Insulated ground cables? (Robert L. Nuckolls, III)
7. 09:44 AM - Re: Z-9 diagram for Corvair (Billy Stewart)
8. 10:10 AM - Re: Insulated ground cables? (C&K)
9. 10:24 AM - Re: Insulated ground cables? (David Saylor)
10. 10:38 AM - ASTM F2245 (D L Josephson)
11. 11:19 AM - Re: Insulated ground cables? (Robert L. Nuckolls, III)
12. 11:21 AM - Re: ASTM F2245 (Robert L. Nuckolls, III)
13. 11:30 AM - Re: ASTM F2245 (Jeff Luckey)
14. 11:44 AM - Re: Insulated ground cables? (Robert Reed)
Message 1
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Subject: | Insulated ground cables? |
Bob and Listers,
I've been working on a few Beech products lately and a question has come up.
Many of the fuel lines are grounded to the airframe by short, thick ground
cables.
Here's a link that shows a typical ground strap. This isn't one of the
planes I'm working on, just a convenient snapshot off the internet:
http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
The question is, why bother to install a ground strap that terminates to an
insulated adel clamp?
About all we can figure is that -if- they're for lightning protection, the
rubber won't offer much relative resistance.
The practice is consistent across several airplanes. Are we missing
something? It's so counterintuitive that there must be a good reason.
--Dave
Message 2
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Subject: | Re: Insulated ground cables? |
On 1/17/2015 8:36 AM, David Saylor wrote:
> Bob and Listers,
>
> I've been working on a few Beech products lately and a question has
> come up.
>
> Many of the fuel lines are grounded to the airframe by short, thick
> ground cables.
>
> Here's a link that shows a typical ground strap. This isn't one of
> the planes I'm working on, just a convenient snapshot off the internet:
>
> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>
> The question is, why bother to install a ground strap that terminates
> to an insulated adel clamp?
>
> About all we can figure is that -if- they're for lightning protection,
> the rubber won't offer much relative resistance.
>
> The practice is consistent across several airplanes. Are we missing
> something? It's so counterintuitive that there must be a good reason.
>
> --Dave
>
>
Just wild speculation, but my 1st guess would be, static dissipation. If
there's any carbon in the rubber at all, it would provide a high
resistance path to dissipate any high voltage static charge buildup
caused by the fuel flowing through the line.
Why they wouldn't just pick a spot for the clamp where it could provide
vibration protection to the line at the same time, is another question....
Message 3
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Subject: | Re:_AeroElectric-List:_Insulated_ground_cables=3F? |
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Message 4
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Subject: | Re: Insulated ground cables? |
That's a good theory. I'll post if I get a sure answer.
On Sat, Jan 17, 2015 at 7:37 AM, Charlie England <ceengland7@gmail.com>
wrote:
> ceengland7@gmail.com>
>
> On 1/17/2015 8:36 AM, David Saylor wrote:
>
>> Bob and Listers,
>>
>> I've been working on a few Beech products lately and a question has come
>> up.
>>
>> Many of the fuel lines are grounded to the airframe by short, thick
>> ground cables.
>>
>> Here's a link that shows a typical ground strap. This isn't one of the
>> planes I'm working on, just a convenient snapshot off the internet:
>>
>> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>>
>> The question is, why bother to install a ground strap that terminates to
>> an insulated adel clamp?
>>
>> About all we can figure is that -if- they're for lightning protection,
>> the rubber won't offer much relative resistance.
>>
>> The practice is consistent across several airplanes. Are we missing
>> something? It's so counterintuitive that there must be a good reason.
>>
>> --Dave
>>
>>
>> Just wild speculation, but my 1st guess would be, static dissipation. If
> there's any carbon in the rubber at all, it would provide a high resistance
> path to dissipate any high voltage static charge buildup caused by the fuel
> flowing through the line.
>
> Why they wouldn't just pick a spot for the clamp where it could provide
> vibration protection to the line at the same time, is another question....
>
>
Message 5
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Subject: | Re: Insulated ground cables? |
I'll look for a contact ribbon. I found this picture. It makes sense.
http://www.interfast.ca/images/115.jpg
On Sat, Jan 17, 2015 at 7:34 AM, <rnjcurtis@charter.net> wrote:
>
>
> Many of the fuel lines are grounded to the airframe by short, thick ground
> cables.
>
> Here's a link that shows a typical ground strap. This isn't one of the
> planes I'm working on, just a convenient snapshot off the internet:
>
> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>
> The question is, why bother to install a ground strap that terminates to
> an insulated adel clamp?
>
> About all we can figure is that -if- they're for lightning protection, the
> rubber won't offer much relative resistance.
>
> The practice is consistent across several airplanes. Are we missing
> something? It's so counterintuitive that there must be a good reason.
>
> --Dave
>
> I believe that you will find, if you remove and inspect the Adel clamp,
> there is a thin metal ribbon woven through the rubber in such a way that it
> makes contact with the fuel line and the metal structure of the clamp.
> This will, in fact ground the fuel line.
>
> Roger
>
> *
>
>
> *
>
>
Message 6
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Subject: | Re: Insulated ground cables? |
At 08:36 2015-01-17, you wrote:
Bob and Listers,
I've been working on a few Beech products lately and a question has come up.
Many of the fuel lines are grounded to the
airframe by short, thick ground cables.
Here's a link that shows a typical ground
strap. This isn't one of the planes I'm working
on, just a convenient snapshot off the internet:
http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
The question is, why bother to install a ground
strap that terminates to an insulated adel clamp?
About all we can figure is that -if- they're for
lightning protection, the rubber won't offer much relative resistance.
The practice is consistent across several
airplanes. Are we missing something? It's so
counterintuitive that there must be a good reason.
--Dave
There is . . .
The padded clamp is for abrasion protection. Micro-vibration
between the tube's surface and mounting (perhaps in combination
with greasy dust) risks erosion of the surface(s) and failure
of the tube.
It doesn't even have to be a 'hard' mounting surface. My
'57 Chevy had a steel brake line resting against a power
steering hose for what had to be years. Oily contaminants
helped gather 'grinding compounds' in the interface. One
night about 1am my brake pedal went to the floor at a stop
sign . . . fortunately out in the country on deserted roads.
I nursed the car into an all night Standard station. The
guy behind the counter was there to pump gas . . . didn't
have a clue as to what might be useful. But he did give me
access to some wrenches and acid core solder I found
in the work bays. I used jumper cables on to hook my hunk
of disconnected brake line across the battery. Got it warm
enough to flow some solder over the hole. But it back on
the car and 'had brakes' albeit a little squishy . . . bubble
in the line.
THAT case was a rubber hose rubbing on a steel tube.
On airplane liquid lines, it's important not only to reduce
the hardness of materials at the clamp up interface (hence
padded clamp) but to make sure the clamp gets a firm grip
on the tube (excludes contaminants and prevents relative
motion). That, brethren, is the reading of THE WORD on
mechanical aspects of liquid line installation.
THE WORD on lightning is found in another book and
discusses an entirely separate constellation of simple
ideas' which drive installation of the bonding straps.
Bob . . .
Message 7
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Subject: | RE: Z-9 diagram for Corvair |
Bob,
I'm building a Zenith 601XLb with a Corvair engine. I'm using the Z-9
diagram, the Corvair/601 Engine Installation Manual By William Wynne and The
AeroElectric Connection 12A as guides/references.
My intentions are mostly fun flying with trips to visit family and
interesting places. It will be day VFR.
My desires are reliability first and foremost.
I have a Dynon EFIS-D100, a EMS-D120, Garmin GTX-327, Icom IC-A210, and
Garmin aera all installed, wired and tested. This was all pretty straight
forward. I'm using tefzel wire, PDIG connectors and the correct crimpers for
all of this.
I'm into the charging system now, and since the ignition system is
battery/alternator powered instead of magneto, my desire is to have a
reliable charging system. If the charging system is malfunctioning, I want
to know about it as soon as possible.
I have the John Deere MIA10338 Alternator and the MIA881279
Rectifier/Regulator. The alternator is a permanent magnet type with single
phase A.C. output coming out of the alternator.
Thanks,
Billy Stewart
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:nuckolls.bob@aeroelectric.com]
Sent: Thursday, January 15, 2015 3:00 PM
Subject: Re: Z-9 diagrm for Corvair
At 22:35 2015-01-14, you wrote:
>Bob,
>
>My version of the AeroElectric book is from 2009 and the Z diagrams
>began at 10. At some point, I downloaded a Z-9 from the website, I
>think around 2009/10. I'm finishing the wiring on my plane and I
>wanted to know if the Z-9 diagram has been updated or if the one I
>have is still the best.
>
Revision (A) is the most current but it will
be updated shortly to include REAL pinouts
for the 4-function module have been firmed
up . . . the device is going to production
pretty soon.
Z09 was crafted as a demonstration project
for the AEC9024 4-function module as well as
a talking paper for a List reader's intention
to incorporate a Corvair engine in his project.
I'll be updating Z09 for attachment to the
AEC9024 installation manual as an exemplar
system that might exploit the AEC9024's features.
Let's talk about your intentions/desires.
Are you going to use a single or three-phase
alternator?
Bob . . .
Message 8
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Subject: | Re: Insulated ground cables? |
On 17/01/2015 12:05 PM, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 08:36 2015-01-17, you wrote:
> Bob and Listers,
>
> I've been working on a few Beech products lately and a question has
> come up.
>
> Many of the fuel lines are grounded to the airframe by short, thick
> ground cables.
>
> Here's a link that shows a typical ground strap. This isn't one of
> the planes I'm working on, just a convenient snapshot off the internet:
>
> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>
> The question is, why bother to install a ground strap that terminates
> to an insulated adel clamp?
>
> About all we can figure is that -if- they're for lightning protection,
> the rubber won't offer much relative resistance.
>
> The practice is consistent across several airplanes. Are we missing
> something? It's so counterintuitive that there must be a good reason.
>
> --Dave
>
> There is . . .
>
> The padded clamp is for abrasion protection. Micro-vibration
> between the tube's surface and mounting (perhaps in combination
> with greasy dust) risks erosion of the surface(s) and failure
> of the tube.
>
> It doesn't even have to be a 'hard' mounting surface. My
> '57 Chevy had a steel brake line resting against a power
> steering hose for what had to be years. Oily contaminants
> helped gather 'grinding compounds' in the interface. One
> night about 1am my brake pedal went to the floor at a stop
> sign . . . fortunately out in the country on deserted roads.
>
> I nursed the car into an all night Standard station. The
> guy behind the counter was there to pump gas . . . didn't
> have a clue as to what might be useful. But he did give me
> access to some wrenches and acid core solder I found
> in the work bays. I used jumper cables on to hook my hunk
> of disconnected brake line across the battery. Got it warm
> enough to flow some solder over the hole. But it back on
> the car and 'had brakes' albeit a little squishy . . . bubble
> in the line.
>
> THAT case was a rubber hose rubbing on a steel tube.
>
> On airplane liquid lines, it's important not only to reduce
> the hardness of materials at the clamp up interface (hence
> padded clamp) but to make sure the clamp gets a firm grip
> on the tube (excludes contaminants and prevents relative
> motion). That, brethren, is the reading of THE WORD on
> mechanical aspects of liquid line installation.
>
> THE WORD on lightning is found in another book and
> discusses an entirely separate constellation of simple
> ideas' which drive installation of the bonding straps.
>
> Bob . . .
>
57 Chevy
86 Dodge same thing. Rubber hose OK but it abraded through a steel brake
line below the master cylinder after about 7 years. There were dual
(split) braking systems by 1986 but the emergency brake was more
effective. I also had a rust out on a 88 Dodge and the pedal went to
the floor despite the dual system.
There has been discussion on bad engine ground cables that then allowed
current to flow through control cables or even sensor grounds. I've seen
some aircraft with metal braided fuel lines going to the engine. I
question the wisdom of that and have wondered whether that could have
been a factor in a failed fuel hose and subsequent fatal engine fire a
few years ago. I have two independent ground cables going to my engine
and sure enough I did once find a problem with one of them on an annual
inspection.
I've come across a couple of those adel clamps with integral metal
ground but never thought about them until now. With several rubber hoses
connecting various parts of some fuel systems, it makes sense to bond it
such that no static can possibly build on any part of the system. Must
check this because I think I might have a section of metal tubing all
nicely insulated in Adel clamps, rubber grommets, and rubber hoses.
Ken
Message 9
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Subject: | Re: Insulated ground cables? |
=8BOK, I understand that using a tight padded clamp will preserve the
clampee=8B. I've repaired much damaged from loose clamps and ty-wrap
s.
I still don't get, unless it's a conducting clamp, why a bonding strap
would be well insulated at one end of the circuit. They're not providing
any mechanical connection. Purely electrical so far as I can see.
I may know a lot more after looking closer at the clamp.
--Dave
On Sat, Jan 17, 2015 at 9:05 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com>
>
> At 08:36 2015-01-17, you wrote:
> Bob and Listers,
>
> I've been working on a few Beech products lately and a question has come
> up.
>
> Many of the fuel lines are grounded to the airframe by short, thick groun
d
> cables.
>
> Here's a link that shows a typical ground strap.=C3=82 This isn't one of
the
> planes I'm working on, just a convenient snapshot off the internet:
>
> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>
> The question is, why bother to install a ground strap that terminates to
> an insulated adel clamp?
>
> About all we can figure is that -if- they're for lightning protection, th
e
> rubber won't offer much relative resistance.
>
> The practice is consistent across several airplanes.=C3=82 Are we missin
g
> something?=C3=82 It's so counterintuitive that there must be a good reas
on.
>
> --Dave
>
> There is . . .
>
> The padded clamp is for abrasion protection. Micro-vibration
> between the tube's surface and mounting (perhaps in combination
> with greasy dust) risks erosion of the surface(s) and failure
> of the tube.
>
> It doesn't even have to be a 'hard' mounting surface. My
> '57 Chevy had a steel brake line resting against a power
> steering hose for what had to be years. Oily contaminants
> helped gather 'grinding compounds' in the interface. One
> night about 1am my brake pedal went to the floor at a stop
> sign . . . fortunately out in the country on deserted roads.
>
> I nursed the car into an all night Standard station. The
> guy behind the counter was there to pump gas . . . didn't
> have a clue as to what might be useful. But he did give me
> access to some wrenches and acid core solder I found
> in the work bays. I used jumper cables on to hook my hunk
> of disconnected brake line across the battery. Got it warm
> enough to flow some solder over the hole. But it back on
> the car and 'had brakes' albeit a little squishy . . . bubble
> in the line.
>
> THAT case was a rubber hose rubbing on a steel tube.
>
> On airplane liquid lines, it's important not only to reduce
> the hardness of materials at the clamp up interface (hence
> padded clamp) but to make sure the clamp gets a firm grip
> on the tube (excludes contaminants and prevents relative
> motion). That, brethren, is the reading of THE WORD on
> mechanical aspects of liquid line installation.
>
> THE WORD on lightning is found in another book and
> discusses an entirely separate constellation of simple
> ideas' which drive installation of the bonding straps.
>
> Bob . . .
>
>
===========
===========
===========
===========
>
>
Message 10
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On 1/16/15 11:59 PM, Jeff Luckey wrote:
> 2. After reviewing F2245 it seems strange that not only is such
> circuit protection not recommended but it is specifically prohibited.
> Seems like
With all due respect, that is simply false with respect both to the
subcommittee's intent (having been a participant or observer in many of
the discussions on this topic) and the current language. People are
commenting on an obsolete edition of the standard that someone pirated
on to the net, not even the current one, and certainly not the one that
is being further refined this month.
Second, a standard permits or prohibits nothing. The point of a standard
is to set a definition which can be referred to. It has no regulatory
impact. FAA will accept a manufacturer's assertion of compliance with
this particular standard as indicating compliance with the light-sport
rules, and will consider others if proposed to them.
If you don't like the standard as it is, get involved in changing it.
The process is very unlike the FAA's rulemaking process: rather than
staying the same for decades, the default is review and updating to meet
current best practices. I have been part of that effort for two years.
It takes some time, and I believe it's worthwhile. I'm involved in
several other standards-making bodies and the ASTM process is faster and
more accessible than most. But it is dependent on the good-faith efforts
of everyone interested in the outcome.
David Josephson
Message 11
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Subject: | Re: Insulated ground cables? |
At 12:23 2015-01-17, you wrote:
>OK, I understand that using a tight padded
>clamp will preserve the clampee. I've
>repaired much damaged from loose clamps and ty-wraps.
>
>I still don't get, unless it's a conducting
>clamp, why a bonding strap would be well
>insulated at one end of the circuit. They're
>not providing any mechanical
>connection. Purely electrical so far as I can see.
>
>I may know a lot more after looking closer at the clamp.
Any sort of 'conductive' clamp can serve no better purpose
than to mitigate potential differences at LOW current.
I.e. static and maybe noise in radios generated by
itty-bitty arcs due differences across separate airframe
grounds . . . recall that any electrical connection worthy
of the name is gas tight. Lots of pressure, welding, soldering,
crimping, or other joining process intended to exclude
moisture and preserve a BOND. There may be a constellation
of simple-ideas that speak to the utility of 'mildly conducive'
Adel clamps; but not that I've heard/read/observed in my travels.
If design goals for airplane include some level of
survivability to lightning strike, then conductive
bushings in a clamp will not be part of that particular
hardening process.
Bob . . .
Message 12
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>It takes some time, and I believe it's worthwhile. I'm involved in
>several other standards-making bodies and the ASTM process is faster
>and more accessible than most. But it is dependent on the good-faith
>efforts of everyone interested in the outcome.
>
>David Josephson
Well put . . .
Bob . . .
Message 13
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"With all due respect, that is simply false with respect both to the
subcommittee's intent (having been a participant or observer in many of
the discussions on this topic) and the current language. "
OK, very good, I'm pleased to hear that. I must be looking at an old copy as you
mention and/or factoring in other people's interpretation - bad on me. However,
there is evidence that people are interpreting the standard as though it
prohibits protecting the feeder in question, however incorrect that may be.
"Second, a standard permits or prohibits nothing. The point of a standard
is to set a definition which can be referred to."
I agree in theory, however in practical application people interpret (or mis-interpret)
standards like this as though they do permit or prohibit.
Thanks for the clarification,
-Jeff
On Saturday, January 17, 2015 10:52 AM, D L Josephson <dlj04@josephson.com> wrote:
On 1/16/15 11:59 PM, Jeff Luckey wrote:
> 2. After reviewing F2245 it seems strange that not only is such
> circuit protection not recommended but it is specifically prohibited.
> Seems like
With all due respect, that is simply false with respect both to the
subcommittee's intent (having been a participant or observer in many of
the discussions on this topic) and the current language. People are
commenting on an obsolete edition of the standard that someone pirated
on to the net, not even the current one, and certainly not the one that
is being further refined this month.
Second, a standard permits or prohibits nothing. The point of a standard
is to set a definition which can be referred to. It has no regulatory
impact. FAA will accept a manufacturer's assertion of compliance with
this particular standard as indicating compliance with the light-sport
rules, and will consider others if proposed to them.
If you don't like the standard as it is, get involved in changing it.
The process is very unlike the FAA's rulemaking process: rather than
staying the same for decades, the default is review and updating to meet
current best practices. I have been part of that effort for two years.
It takes some time, and I believe it's worthwhile. I'm involved in
several other standards-making bodies and the ASTM process is faster and
more accessible than most. But it is dependent on the good-faith efforts
of everyone interested in the outcome.
David Josephson
Message 14
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Subject: | Re: Insulated ground cables? |
Test it to see if there a connection.
Bob Reed
Sent from my iPhone
> On Jan 17, 2015, at 12:23 PM, David Saylor <saylor.dave@gmail.com> wrote:
>
> =8BOK, I understand that using a tight padded clamp will preserve th
e clampee=8B. I've repaired much damaged from loose clamps and ty-wra
ps.
>
> I still don't get, unless it's a conducting clamp, why a bonding strap wou
ld be well insulated at one end of the circuit. They're not providing any m
echanical connection. Purely electrical so far as I can see.
>
> I may know a lot more after looking closer at the clamp.
>
> --Dave
>
>> On Sat, Jan 17, 2015 at 9:05 AM, Robert L. Nuckolls, III <nuckolls.bob@ae
roelectric.com> wrote:
lls.bob@aeroelectric.com>
>>
>> At 08:36 2015-01-17, you wrote:
>> Bob and Listers,
>>
>> I've been working on a few Beech products lately and a question has come u
p.
>>
>> Many of the fuel lines are grounded to the airframe by short, thick groun
d cables.
>>
>> Here's a link that shows a typical ground strap.=C3=82 This isn't one of
the planes I'm working on, just a convenient snapshot off the internet:
>>
>> http://www.csobeech.com/images/Baron-FuelSelectorCable.jpg
>>
>> The question is, why bother to install a ground strap that terminates to a
n insulated adel clamp?
>>
>> About all we can figure is that -if- they're for lightning protection, th
e rubber won't offer much relative resistance.
>>
>> The practice is consistent across several airplanes.=C3=82 Are we missin
g something?=C3=82 It's so counterintuitive that there must be a good reaso
n.
>>
>> --Dave
>>
>> There is . . .
>>
>> The padded clamp is for abrasion protection. Micro-vibration
>> between the tube's surface and mounting (perhaps in combination
>> with greasy dust) risks erosion of the surface(s) and failure
>> of the tube.
>>
>> It doesn't even have to be a 'hard' mounting surface. My
>> '57 Chevy had a steel brake line resting against a power
>> steering hose for what had to be years. Oily contaminants
>> helped gather 'grinding compounds' in the interface. One
>> night about 1am my brake pedal went to the floor at a stop
>> sign . . . fortunately out in the country on deserted roads.
>>
>> I nursed the car into an all night Standard station. The
>> guy behind the counter was there to pump gas . . . didn't
>> have a clue as to what might be useful. But he did give me
>> access to some wrenches and acid core solder I found
>> in the work bays. I used jumper cables on to hook my hunk
>> of disconnected brake line across the battery. Got it warm
>> enough to flow some solder over the hole. But it back on
>> the car and 'had brakes' albeit a little squishy . . . bubble
>> in the line.
>>
>> THAT case was a rubber hose rubbing on a steel tube.
>>
>> On airplane liquid lines, it's important not only to reduce
>> the hardness of materials at the clamp up interface (hence
>> padded clamp) but to make sure the clamp gets a firm grip
>> on the tube (excludes contaminants and prevents relative
>> motion). That, brethren, is the reading of THE WORD on
>> mechanical aspects of liquid line installation.
>>
>> THE WORD on lightning is found in another book and
>> discusses an entirely separate constellation of simple
>> ideas' which drive installation of the bonding straps.
>>
>> Bob . . .
>>
>>
>>
>>
>> =========================
>> br> fts!)
>> r> > /www.aeroelectric.com" target="_blank">www.aeroelectric.com
>> w.buildersbooks.com" target="_blank">www.buildersbooks.com
>> p.com" target="_blank">www.homebuilthelp.com
>> e.com" target="_blank">www.mypilotstore.com
>> " target="_blank">www.mrrace.com
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>> -Matt Dralle, List Admin.
>> =========================
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lectric-List
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>
>
>
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>
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