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JFLEISC(at)aol.com
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rocketbob(at)gmail.com
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 Posted: Sun May 04, 2008 12:40 pm Post subject: Proseal remover? |
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There's a product called SkyRestore that will soften up proseal. I've never used it but here's a link to some:
[url=http://aerosafe.com/shopping/start.php?browse=1&cat ]http://aerosafe.com/shopping/start.php?browse=1&cat [/url]
Let us know if it works!
Regards,
Bob Japundza
RV-6 flying F1 under const.
On Sun, May 4, 2008 at 2:05 PM, <JFLEISC(at)aol.com (JFLEISC(at)aol.com)> wrote:
[quote] Anyone have a method for chemically removing Proseal from the inside of a tank? Mine are over 18 years old. I bought the plane used 12 years ago and the right tank had a minor leak back then and, to my surprise  , it hasn't gotten any better. Anyway it's not minor any more and I have the tank off and have a couple gallons of MEK in it but its not doing anything fast enough (that may be good for finish cleaning but not for bulk removal). Paint stripper maybe? I don't want to open them up just yet because if I have to scrub it off I know I'll miss something and have to do the process again in the middle of resealing. Thanks.
Jim
Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food.
[b]
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rickpegser(at)yahoo.com
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| Posted: Sun May 04, 2008 12:59 pm Post subject: Proseal remover? |
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stop right now. you have a leak go after that leak soaking the tank will only cause more leaks and require that you disassemble the tank to cure them.
call me and i will walk you thru tank repair. 559-270-7113
rick m
a+p,i/a
JFLEISC(at)aol.com wrote:
[quote] Anyone have a method for chemically removing Proseal from the inside of a tank? Mine are over 18 years old. I bought the plane used 12 years ago and the right tank had a minor leak back then and, to my surprise , it hasn't gotten any better. Anyway it's not minor any more and I have the tank off and have a couple gallons of MEK in it but its not doing anything fast enough (that may be good for finish cleaning but not for Be a better friend, newshound, and [quote][b]
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rickpegser(at)yahoo.com
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| Posted: Sun May 04, 2008 1:15 pm Post subject: Proseal remover? |
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stop right now. you have a leak go after that leak soaking the tank will only cause more leaks and require that you disassemble the tank to cure them.
call me and i will walk you thru tank repair. 559-270-7113
rick m
a+p,i/a
JFLEISC(at)aol.com wrote:
[quote] Anyone have a method for chemically removing Proseal from the inside of a tank? Mine are over 18 years old. I bought the plane used 12 years ago and the right tank had a minor leak back then and, to my surprise , it hasn't gotten any better. Anyway it's not minor any more and I have the tank off and have a couple gallons of MEK in it but its not doing anything fast enough (that may be good for finish cleaning but not for Be a better friend, newshound, and [quote][b]
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JFLEISC(at)aol.com
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| Posted: Sun May 04, 2008 1:37 pm Post subject: Proseal remover? |
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In a message dated 5/4/2008 5:17:46 P.M. Eastern Daylight Time, rickpegser(at)yahoo.com writes:
| Quote: | stop right now. you have a leak go after that leak soaking the tank will only cause more leaks and require that you disassemble the tank to cure them.
|
I probably didn't make myself clear. I had a small leak when I first got the plane. Now I have dozens of them. I already have the tanks off (along with the wings and fuselage in my barn). I have a laundry list of other repairs and updates I have been putting off for years and now is the time. The tank thing was out of hand before I did anything. This -4 has nearly 2000 hard hours on it.
Jim
Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food.
[quote][b]
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chaskuss(at)yahoo.com
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| Posted: Mon May 05, 2008 10:04 am Post subject: Proseal remover? |
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Jim
Putting MEK in the tank has only made your problem worse. You might have turned a single leak into several by adding MEK to the tank. You had better contact Richard and let him walk you through how to repair that leak.
Charlie Kuss
--- On Sun, 5/4/08, JFLEISC(at)aol.com <JFLEISC(at)aol.com> wrote:
| Quote: | From: JFLEISC(at)aol.com <JFLEISC(at)aol.com>
Subject: Proseal remover?
To: rv-list(at)matronics.com
Date: Sunday, May 4, 2008, 2:05 PM
Anyone have a method for chemically removing Proseal from
the inside of a
tank? Mine are over 18 years old. I bought the plane used
12 years ago and the
right tank had a minor leak back then and, to my surprise
, it hasn't
gotten any better. Anyway it's not minor any more and I
have the tank off and
have a couple gallons of MEK in it but its not doing
anything fast enough (that
may be good for finish cleaning but not for bulk removal).
Paint stripper
maybe? I don't want to open them up just yet because if
I have to scrub it off I
know I'll miss something and have to do the process
again in the middle of
resealing. Thanks.
Jim
**************Wondering what's for Dinner Tonight? Get
new twists on family
favorites at AOL Food.
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
|
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
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aerokinetic(at)sbcglobal.
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| Posted: Tue May 06, 2008 5:46 am Post subject: Proseal remover? |
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I remember hearing many years ago in A&P school that Proseal (890) has no known solvent. There are a number of things that will cause it to swell and soften it a little, MEK being one of them, but there is nothing that will melt it away.
Sounds indeed like you made a small problem into a big one. I would pull the tank and remove the aft wall or cut holes in it and scrape out all the (now soft) proseal with a phenolic scraper, and then reseal the tank with a fresh batch. Then seal the aft wall in place again or seal covers on the holes.
I had to reseal one of my tanks in the same way a number of years back, and chose to cut circular holes to work through and then made covers for them. Still holding.
Scott
RV-4 flying off and on since '92
[quote][b]
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rickpegser(at)yahoo.com
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| Posted: Tue May 06, 2008 5:57 am Post subject: Proseal remover? |
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Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101.
static loads on a fuel tank are less then .5 psi. duct tape can hold .5 psi. dynamic loads are variable due to high g loading and can reach 4
psi, with tank destruction emanate. the problem with checking tanks is the static pressure loading is applied to all surfaces and they need to be stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as it flexes. tearing the sealant bonds.
so lets assume that you built it close to right and now want to test it. water, fuel, any material with the exception of the original sealant will contaminate the joint during testing. so how do we remove the contaminates? we don't contaminate in the first place. the sealants we are using are sensitive to contaminates so air or better nitrogen is the testing medium of choice.
after inspecting aircraft with properly applied pro-seal that had over twenty years in service, the stuff sticks. sloshing does not work and will result in a crash, the unfortunate part of this is that the pilot is always the first person at the crash site.. fire and medic support might take a little longer arriving. do not slosh tanks
types of leaks.
seam leaks, very rare, normally caused by poor construction, or extreme g loading.
fastener leaks, more common also caused by high g loading and flexing of the structure, compounded but poor sealing practices. all tank fasteners are to be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly applied sealant, wrong nut plates , they should be all domed and sealed. too long of screw that goes through the nut plate dome. bad gaskets, failed orings. rotation of a fitting after sealant has dried. always use two wrenches when removing lines.
the primary problem with tank repair is the lack of structural integrity of this tank. riveted tanks and the repair tricks where designed around the larger transport type aircraft. pro-seal sticks well and can be a problem to break the seams apart without disturbing/destroying the structure.
the best way that i have found to stop small leaks at fasteners and seams is to apply a heavy vacuum to the outside of the tank at the effected area to draw any remaining fuel out and and suck the sealant in to the void. additional rivets added along seam lines while still wet helps to.
sealant application tricks.
clean /clean /clean. pro-seal dose not like oil and most primers but loves a good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad for you
proper fit of parts, don't expect pro-seal to fill gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for fillets and fastener sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale really helps.
use the longest pot life you can, i have found that 1/2 stuff to be almost useless for most jobs.
the proper place for sealant is on the inside of the tank not globed on the outside beside it looks ugly.
tips of opening seams
sharpend putty knives are great but be sure to round the corners to help prevent gouges. take your time here. gentle is better.
removal of sealant
scotch bright disks work great. wear a mask. and realodine after done.
tank testing, quick easy and cheap
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a loop with three feet high on both sides
add nitrogen until the water is four feet higher on one side then the other. you now have 2 psi in the tank. care should be taken here, fill slowly.
spray the seams with soapy water and look for bubbles. use hand soap or aircraft soap, some soaps are bad for alum.
how to find that damn mystery leak i have tried everything else.
sometimes really small leaks are the worse to find, but one way to track them down is to apply dye-pen developer to the outside of the tank it will show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
Be a better friend, newshound, and [quote][b]
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webmaster(at)flion.com
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| Posted: Tue May 06, 2008 7:37 am Post subject: Proseal remover? |
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Domed nut plates? Van’s doesn’t supply those or call them out in the plans. I put a little fuel lube on the screws that hold the access plate on and I had no leaks when testing the tanks (except once when I forgot to tighten them down). Should I be concerned?
Also, I’m getting to the point where I’ll be hooking my fuel system to the engine. Airflow performance calls for purging the tanks and lines with fuel before doing this. What is the best way to do this? Will it hurt to use my electric pump to move the fuel, or will the filter be sufficient to protect it during the initial purge? Any replies, not just Richard’s, will be appreciated.
Patrick Kelley – RV-6A – Engine hung, beginning FWF process
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of RICHARD MILLER
Sent: Tuesday, May 06, 2008 6:54 AM
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101.
*** stuff snipped ***
types of leaks.
*** more stuff snipped ***
access plate/fitting leaks, most common. cause improperly applied sealant, wrong nut plates , they should be all domed and sealed. too long of screw that goes through the nut plate dome. bad gaskets, failed orings. rotation of a fitting after sealant has dried. always use two wrenches when removing lines.
*** remaining text snipped ***
[quote][b]
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jan(at)claver.demon.co.uk
Guest
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| Posted: Tue May 06, 2008 10:16 am Post subject: Proseal remover? |
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Hi Richard,
I will be doing my hand build tanks later on this summer. I have read your article with great interest. First … I have bought the domed nut plates… they are used on commercial planes from what I understand … and should make a perfect seal with a “O” ring .. Then cover the nut plate after fitting with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ?? That is a new one to me … I thought cleaning with Aluprep …rinse with water … and scuff the seams is fine ??
Appreciate you comments on this
Best regards
Jan
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of RICHARD MILLER
Sent: 06 May 2008 14:54
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101.
static loads on a fuel tank are less then .5 psi. duct tape can hold .5 psi. dynamic loads are variable due to high g loading and can reach 4
psi, with tank destruction emanate. the problem with checking tanks is the static pressure loading is applied to all surfaces and they need to be stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as it flexes. tearing the sealant bonds.
so lets assume that you built it close to right and now want to test it. water, fuel, any material with the exception of the original sealant will contaminate the joint during testing. so how do we remove the contaminates? we don't contaminate in the first place. the sealants we are using are sensitive to contaminates so air or better nitrogen is the testing medium of choice.
after inspecting aircraft with properly applied pro-seal that had over twenty years in service, the stuff sticks. sloshing does not work and will result in a crash, the unfortunate part of this is that the pilot is always the first person at the crash site.. fire and medic support might take a little longer arriving. [b]do not slosh tanks[/b]
[b]types of leaks[/b].
seam leaks, very rare, normally caused by poor construction, or extreme g loading.
fastener leaks, more common also caused by high g loading and flexing of the structure, compounded but poor sealing practices. all tank fasteners are to be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly applied sealant, wrong nut plates , they should be all domed and sealed. too long of screw that goes through the nut plate dome. bad gaskets, failed orings. rotation of a fitting after sealant has dried. always use two wrenches when removing lines.
the primary problem with tank repair is the lack of structural integrity of this tank. riveted tanks and the repair tricks where designed around the larger transport type aircraft. pro-seal sticks well and can be a problem to break the seams apart without disturbing/destroying the structure.
the best way that i have found to stop small leaks at fasteners and seams is to apply a heavy vacuum to the outside of the tank at the effected area to draw any remaining fuel out and and suck the sealant in to the void. additional rivets added along seam lines while still wet helps to.
[b]sealant application tricks[/b].
clean /clean /clean. pro-seal dose not like oil and most primers but loves a good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad for you
proper fit of parts, don't expect pro-seal to fill gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for fillets and fastener sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale really helps.
use the longest pot life you can, i have found that 1/2 stuff to be almost useless for most jobs.
the proper place for sealant is on the inside of the tank not globed on the outside beside it looks ugly.
[b]tips of opening seams[/b]
sharpend putty knives are great but be sure to round the corners to help prevent gouges. take your time here. gentle is better.
[b]removal of sealant[/b]
scotch bright disks work great. wear a mask. and realodine after done.
[b]tank testing, quick easy and cheap[/b]
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a loop with three feet high on both sides
add nitrogen until the water is four feet higher on one side then the other. you now have 2 psi in the tank. care should be taken here, fill slowly.
spray the seams with soapy water and look for bubbles. use hand soap or aircraft soap, some soaps are bad for alum.
[b]how to find that damn mystery leak i have tried everything else.[/b]
sometimes really small leaks are the worse to find, but one way to track them down is to apply dye-pen developer to the outside of the tank it will show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
Be a better friend, newshound, and | Quote: | | http://www.matronics.com/Navigator?RV-List |
0123456789
[quote][b]
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Larry Bowen
Joined: 09 Jan 2006
Posts: 802
Location: NC, USA
|
| Posted: Tue May 06, 2008 2:12 pm Post subject: Proseal remover? |
|
|
FYI, I used domed nut plates on my RV-8 tanks....and had to cut a couple of
them off because they interfered with the fuel pick-up. Sometimes
second-guessing uncle Van doesn't pay off....
--
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com
On Tue, May 6, 2008 at 2:14 PM, jan <jan(at)claver.demon.co.uk> wrote:
[quote] Hi Richard,
I will be doing my hand build tanks later on this summer. I have read your
article with great interest. First … I have bought the domed nut plates…
they are used on commercial planes from what I understand … and should make
a perfect seal with a "O" ring .. Then cover the nut plate after fitting
with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ?? That is a new one
to me … I thought cleaning with Aluprep …rinse with water … and scuff the
seams is fine ??
Appreciate you comments on this
Best regards
Jan
------------------------------
*From:* owner-rv-list-server(at)matronics.com [mailto:
owner-rv-list-server(at)matronics.com] *On Behalf Of *RICHARD MILLER
*Sent:* 06 May 2008 14:54
*To:* rv-list(at)matronics.com
*Subject:* Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks, lets cover fuel
tank 101.
static loads on a fuel tank are less then .5 psi. duct tape can hold .5
psi. dynamic loads are variable due to high g loading and can reach 4
psi, with tank destruction emanate. the problem with checking tanks is
the static pressure loading is applied to all surfaces and they need to be
stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as it flexes.
tearing the sealant bonds.
so lets assume that you built it close to right and now want to test it.
water, fuel, any material with the exception of the original sealant will
contaminate the joint during testing. so how do we remove the contaminates?
we don't contaminate in the first place. the sealants we are using are
sensitive to contaminates so air or better nitrogen is the testing medium of
choice.
after inspecting aircraft with properly applied pro-seal that had over
twenty years in service, the stuff sticks. sloshing does not work and will
result in a crash, the unfortunate part of this is that the pilot is always
the first person at the crash site.. fire and medic support might take a
little longer arriving. *do not slosh tanks*
*types of leaks*.
seam leaks, very rare, normally caused by poor construction, or extreme g
loading.
fastener leaks, more common also caused by high g loading and flexing of
the structure, compounded but poor sealing practices. all tank fasteners are
to be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly applied
sealant, wrong nut plates , they should be all domed and sealed. too long
of screw that goes through the nut plate dome. bad gaskets, failed orings
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
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_________________
Larry Bowen
RV-8 SOLD,
RV-7QB in progress... |
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chaskuss(at)yahoo.com
Guest
|
| Posted: Tue May 06, 2008 3:04 pm Post subject: Proseal remover? |
|
|
Jan
Alodining the interior of the tank does 2 things. It gives you some measure of corrosion protection (since you can't prime the interior). Alodine also improves the grip of the ProSeal to the aluminum.
Charlie Kuss
--- On Tue, 5/6/08, jan <jan(at)claver.demon.co.uk> wrote:
| Quote: | From: jan <jan(at)claver.demon.co.uk>
Subject: RE: Proseal remover?
To: rv-list(at)matronics.com
Date: Tuesday, May 6, 2008, 2:14 PM
Hi Richard,
I will be doing my hand build tanks later on this summer. I
have read your
article with great interest. First ... I have bought the
domed nut plates...
they are used on commercial planes from what I understand
... and should
make a perfect seal with a "O" ring .. Then cover
the nut plate after
fitting with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ??
That is a new one
to me ... I thought cleaning with Aluprep ...rinse with
water ... and scuff
the seams is fine ??
Appreciate you comments on this
Best regards
Jan
_____
From: owner-rv-list-server(at)matronics.com
[mailto:owner-rv-list-server(at)matronics.com] On Behalf Of
RICHARD MILLER
Sent: 06 May 2008 14:54
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks,
lets cover fuel
tank 101.
static loads on a fuel tank are less then .5 psi. duct tape
can hold .5 psi.
dynamic loads are variable due to high g loading and can
reach 4
psi, with tank destruction emanate. the problem with
checking tanks is the
static pressure loading is applied to all surfaces and they
need to be
stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as
it flexes. tearing
the sealant bonds.
so lets assume that you built it close to right and now
want to test it.
water, fuel, any material with the exception of the
original sealant will
contaminate the joint during testing. so how do we remove
the contaminates?
we don't contaminate in the first place. the sealants
we are using are
sensitive to contaminates so air or better nitrogen is the
testing medium of
choice.
after inspecting aircraft with properly applied pro-seal
that had over
twenty years in service, the stuff sticks. sloshing does
not work and will
result in a crash, the unfortunate part of this is that the
pilot is always
the first person at the crash site.. fire and medic support
might take a
little longer arriving. do not slosh tanks
types of leaks.
seam leaks, very rare, normally caused by poor
construction, or extreme g
loading.
fastener leaks, more common also caused by high g loading
and flexing of the
structure, compounded but poor sealing practices. all tank
fasteners are to
be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly
applied sealant,
wrong nut plates , they should be all domed and sealed. too
long of screw
that goes through the nut plate dome. bad gaskets, failed
orings. rotation
of a fitting after sealant has dried. always use two
wrenches when removing
lines.
the primary problem with tank repair is the lack of
structural integrity of
this tank. riveted tanks and the repair tricks where
designed around the
larger transport type aircraft. pro-seal sticks well and
can be a problem to
break the seams apart without disturbing/destroying the
structure.
the best way that i have found to stop small leaks at
fasteners and seams is
to apply a heavy vacuum to the outside of the tank at the
effected area to
draw any remaining fuel out and and suck the sealant in to
the void.
additional rivets added along seam lines while still wet
helps to.
sealant application tricks.
clean /clean /clean. pro-seal dose not like oil and most
primers but loves a
good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps
with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad
for you
proper fit of parts, don't expect pro-seal to fill
gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for
fillets and fastener
sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale
really helps.
use the longest pot life you can, i have found that 1/2
stuff to be almost
useless for most jobs.
the proper place for sealant is on the inside of the tank
not globed on the
outside beside it looks ugly.
tips of opening seams
sharpend putty knives are great but be sure to round the
corners to help
prevent gouges. take your time here. gentle is better.
removal of sealant
scotch bright disks work great. wear a mask. and realodine
after done.
tank testing, quick easy and cheap
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a
loop with three feet
high on both sides
add nitrogen until the water is four feet higher on one
side then the other.
you now have 2 psi in the tank. care should be taken here,
fill slowly.
spray the seams with soapy water and look for bubbles. use
hand soap or
aircraft soap, some soaps are bad for alum.
how to find that damn mystery leak i have tried everything
else.
sometimes really small leaks are the worse to find, but one
way to track
them down is to apply dye-pen developer to the outside of
the tank it will
show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
_____
Be a better friend, newshound, and
<http://www.matronics.com/Navigator?RV-List>
<http://www.matronics.com/contribution>
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chaskuss(at)yahoo.com
Guest
|
| Posted: Tue May 06, 2008 3:17 pm Post subject: Proseal remover? |
|
|
Pat,
NAS 1473-A08 fuel tank nut plates are what almost all certified aircraft use. See
http://www.wicksaircraft.com/catalog/product_cat.php/subid 381/index.html
I used them in my project on the recommendation of my local RV guru. That said, there are other ways of preventing the infamous RV fuel tank access cover leak. (Caused by fuel leaking between the common K1000 nutplates Vans provides and the threads of the attaching screws.
Some builders substitute goops of ProSeal for the supplied cork gasket. This works, but can make future removal of the access cover a hassle.
Other builders purchase special #8 pan head machine screws from vendors like MSC or McMaster-Carr. These special screws have a groove for a sealing O-ring under the head of the screw. If you go this route, be sure to specify that you want VITON O-rings with the screws. (The standard Silicone O-rings won't hold up to either 100LL or auto fuels). These screws are cheaper than the NAS 1473 nutplates and work well on tanks which have already been built using the supplied K1000 screws.
Using either the NAS 1473 nutplates or special screws, allows you to use the supplied cork gaskets with no leaks and easy future removal of your access covers.
Choose which method you want to use and blaze on!
Charlie Kuss
PS Unlike Larry, I had no interference problems between my NAS 1473 nutplates and my fuel pick ups. If you want, I can supply photos of what the NAS 1473 nutplates look like when installed. Contact me directly, if interested
--- On Tue, 5/6/08, Patrick Kelley <webmaster(at)flion.com> wrote:
| Quote: | From: Patrick Kelley <webmaster(at)flion.com>
Subject: RE: Proseal remover?
To: rv-list(at)matronics.com
Date: Tuesday, May 6, 2008, 11:33 AM
Domed nut plates? Van's doesn't supply those or
call them out in the plans.
I put a little fuel lube on the screws that hold the access
plate on and I
had no leaks when testing the tanks (except once when I
forgot to tighten
them down). Should I be concerned?
Also, I'm getting to the point where I'll be
hooking my fuel system to the
engine. Airflow performance calls for purging the tanks
and lines with fuel
before doing this. What is the best way to do this? Will
it hurt to use my
electric pump to move the fuel, or will the filter be
sufficient to protect
it during the initial purge? Any replies, not just
Richard's, will be
appreciated.
Patrick Kelley - RV-6A - Engine hung, beginning FWF process
From: owner-rv-list-server(at)matronics.com
[mailto:owner-rv-list-server(at)matronics.com] On Behalf Of
RICHARD MILLER
Sent: Tuesday, May 06, 2008 6:54 AM
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks,
lets cover fuel
tank 101.
*** stuff snipped ***
types of leaks.
*** more stuff snipped ***
access plate/fitting leaks, most common. cause improperly
applied sealant,
wrong nut plates , they should be all domed and sealed. too
long of screw
that goes through the nut plate dome. bad gaskets, failed
orings. rotation
of a fitting after sealant has dried. always use two
wrenches when removing
lines.
*** remaining text snipped ***
|
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rickpegser(at)yahoo.com
Guest
|
| Posted: Tue May 06, 2008 3:25 pm Post subject: Proseal remover? |
|
|
hi guys
jan i was taught to be a litle anal retentive and by the way had to follow boeing spec's so everything gets alodined. clear for skins and gold for every thing else. besides i like the color. and water from bad fuel is bad for alum tanks.
larry if they don't leak now why play with it. but when they start to leak change them out when you pull the tank. it should only take about an hour per tank.
about fuel filters, airflow performance has a filter prior to the twin pump setup it will stop any thing big enough to damage the pumps, but, big but, do you want to risk your bird on one fuel filter. install one filter per tank prior to the selector valve. and sleep better at night. remember the airflow system much more pressure then a carb. i have never like the one filter idea in certified aircraft. maybe i should apply for an stc for two. airflow fuel filters are an annual replacement item, don't cheat
Larry Bowen <larry(at)bowenaero.com> wrote:
[quote]FYI, I used domed nut plates on my RV-8 tanks....and had to cut a couple of them off because they interfered with the fuel pick-up. Sometimes second-guessing uncle Van doesn't pay off....
--
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com
On Tue, May 6, 2008 at 2:14 PM, jan <jan(at)claver.demon.co.uk (jan(at)claver.demon.co.uk)> wrote:
[quote] Hi Richard,
I will be doing my hand build tanks later on this summer. I have read your article with great interest. First … I have bought the domed nut plates… they are used on commercial planes from what I understand … and should make a perfect seal with a "O" ring .. Then cover the nut plate after fitting with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ?? That is a new one to me … I thought cleaning with Aluprep …rinse with water … and scuff the seams is fine ??
Appreciate you comments on this
Best regards
Jan
From: owner-rv-list-server(at)matronics.com (owner-rv-list-server(at)matronics.com) [mailto:owner-rv-list-server(at)matronics.com (owner-rv-list-server(at)matronics.com)] On Behalf Of RICHARD MILLER
Sent: 06 May 2008 14:54
To: rv-list(at)matronics.com (rv-list(at)matronics.com)
Subject: Re: RV-List: Proseal remover?
Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101.
static loads on a fuel tank are less then .5 psi. duct tape can hold .5 psi. dynamic loads are variable due to high g loading and can reach 4
psi, with tank destruction emanate. the problem with checking tanks is the static pressure loading is applied to all surfaces and they need to be stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as it flexes. tearing the sealant bonds.
so lets assume that you built it close to right and now want to test it. water, fuel, any material with the exception of the original sealant will contaminate the joint during testing. so how do we remove the contaminates? we don't contaminate in the first place. the sealants we are using are sensitive to contaminates so air or better nitrogen is the testing medium of choice.
after inspecting aircraft with properly applied pro-seal that had over twenty years in service, the stuff sticks. sloshing does not work and will result in a crash, the unfortunate part of this is that the pilot is always the first person at the crash site.. fire and medic support might take a little longer arriving. [b]do not slosh tanks[/b]
[b]types of leaks[/b].
seam leaks, very rare, normally caused by poor construction, or extreme g loading.
fastener leaks, more common also caused by high g loading and flexing of the structure, compounded but poor sealing practices. all tank fasteners are to be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly applied sealant, wrong nut plates , they should be all domed and sealed. too long of screw that goes through the nut plate dome. bad gaskets, failed orings. rotation of a fitting after sealant has dried. always use two wrenches when removing lines.
the primary problem with tank repair is the lack of structural integrity of this tank. riveted tanks and the repair tricks where designed around the larger transport type aircraft. pro-seal sticks well and can be a problem to break the seams apart without disturbing/destroying the structure.
the best way that i have found to stop small leaks at fasteners and seams is to apply a heavy vacuum to the outside of the tank at the effected area to draw any remaining fuel out and and suck the sealant in to the void. additional rivets added along seam lines while still wet helps to.
[b]sealant application tricks[/b].
clean /clean /clean. pro-seal dose not like oil and most primers but loves a good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad for you
proper fit of parts, don't expect pro-seal to fill gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for fillets and fastener sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale really helps.
use the longest pot life you can, i have found that 1/2 stuff to be almost useless for most jobs.
the proper place for sealant is on the inside of the tank not globed on the outside beside it looks ugly.
[b]tips of opening seams[/b]
sharpend putty knives are great but be sure to round the corners to help prevent gouges. take your time here. gentle is better.
[b]removal of sealant[/b]
scotch bright disks work great. wear a mask. and realodine after done.
[b]tank testing, quick easy and cheap[/b]
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a loop with three feet high on both sides
add nitrogen until the water is four feet higher on one side then the other. you now have 2 psi in the tank. care should be taken here, fill slowly.
spray the seams with soapy water and look for bubbles. use hand soap or aircraft soap, some soaps are bad for alum.
[b]how to find that damn mystery leak i have tried everything else.[/b]
sometimes really small leaks are the worse to find, but one way to track them down is to apply dye-pen developer to the outside of the tank it will show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
Be a better friend, newshound, and
0
[quote][b] t="_blank">http://www.matronics.com/Navigator?RV-List a>http://forums.matronics.com Be a better friend, newshound, and [quote][b]
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jan(at)claver.demon.co.uk
Guest
|
| Posted: Wed May 07, 2008 9:40 am Post subject: Proseal remover? |
|
|
Hi Richard, (nothing wrong with perfection .. J …) & Charles
Is the reason for using clear and gold Alodine purely esthetic or is there a technical (chemical) reason why they are use on different parts of the aircraft (at Boeing) ? I have used the “gold” Alodine quite a lot – prior to painting … on several parts of the RV I am building. Especially the spar.
From a adhesion point – paint does stick very well to a Alodined surface – Does the maker of ProSeal have any official policy on using Alodine prior to application of its product?
Do you know “how many / how widely” the practice of alodining the inside of the tanks are ??
Jan
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of RICHARD MILLER
Sent: 07 May 2008 00:22
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
hi guys
jan i was taught to be a litle anal retentive and by the way had to follow boeing spec's so everything gets alodined. clear for skins and gold for every thing else. besides i like the color. and water from bad fuel is bad for alum tanks.
larry if they don't leak now why play with it. but when they start to leak change them out when you pull the tank. it should only take about an hour per tank.
about fuel filters, airflow performance has a filter prior to the twin pump setup it will stop any thing big enough to damage the pumps, but, [b]big but, do you want to risk your bird on one fuel filter. [/b]install one filter per tank prior to the selector valve. and sleep better at night. remember the airflow system much more pressure then a carb. i have never like the one filter idea in certified aircraft. maybe i should apply for an stc for two. airflow fuel filters are an annual replacement item, don't cheat
Larry Bowen <larry(at)bowenaero.com> wrote:
[quote]
FYI, I used domed nut plates on my RV-8 tanks....and had to cut a couple of them off because they interfered with the fuel pick-up. Sometimes second-guessing uncle Van doesn't pay off....
--
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com
On Tue, May 6, 2008 at 2:14 PM, jan <jan(at)claver.demon.co.uk (jan(at)claver.demon.co.uk)> wrote:
Hi Richard,
I will be doing my hand build tanks later on this summer. I have read your article with great interest. First … I have bought the domed nut plates… they are used on commercial planes from what I understand … and should make a perfect seal with a "O" ring .. Then cover the nut plate after fitting with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ?? That is a new one to me … I thought cleaning with Aluprep …rinse with water … and scuff the seams is fine ??
Appreciate you comments on this
Best regards
Jan
From: owner-rv-list-server(at)matronics.com (owner-rv-list-server(at)matronics.com) [mailto:owner-rv-list-server(at)matronics.com (owner-rv-list-server(at)matronics.com)] On Behalf Of RICHARD MILLER
Sent: 06 May 2008 14:54
To: rv-list(at)matronics.com (rv-list(at)matronics.com)
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101.
static loads on a fuel tank are less then .5 psi. duct tape can hold .5 psi. dynamic loads are variable due to high g loading and can reach 4
psi, with tank destruction emanate. the problem with checking tanks is the static pressure loading is applied to all surfaces and they need to be stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as it flexes. tearing the sealant bonds.
so lets assume that you built it close to right and now want to test it. water, fuel, any material with the exception of the original sealant will contaminate the joint during testing. so how do we remove the contaminates? we don't contaminate in the first place. the sealants we are using are sensitive to contaminates so air or better nitrogen is the testing medium of choice.
after inspecting aircraft with properly applied pro-seal that had over twenty years in service, the stuff sticks. sloshing does not work and will result in a crash, the unfortunate part of this is that the pilot is always the first person at the crash site.. fire and medic support might take a little longer arriving. do not slosh tanks
types of leaks.
seam leaks, very rare, normally caused by poor construction, or extreme g loading.
fastener leaks, more common also caused by high g loading and flexing of the structure, compounded but poor sealing practices. all tank fasteners are to be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly applied sealant, wrong nut plates , they should be all domed and sealed. too long of screw that goes through the nut plate dome. bad gaskets, failed orings. rotation of a fitting after sealant has dried. always use two wrenches when removing lines.
the primary problem with tank repair is the lack of structural integrity of this tank. riveted tanks and the repair tricks where designed around the larger transport type aircraft. pro-seal sticks well and can be a problem to break the seams apart without disturbing/destroying the structure.
the best way that i have found to stop small leaks at fasteners and seams is to apply a heavy vacuum to the outside of the tank at the effected area to draw any remaining fuel out and and suck the sealant in to the void. additional rivets added along seam lines while still wet helps to.
sealant application tricks.
clean /clean /clean. pro-seal dose not like oil and most primers but loves a good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad for you
proper fit of parts, don't expect pro-seal to fill gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for fillets and fastener sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale really helps.
use the longest pot life you can, i have found that 1/2 stuff to be almost useless for most jobs.
the proper place for sealant is on the inside of the tank not globed on the outside beside it looks ugly.
tips of opening seams
sharpend putty knives are great but be sure to round the corners to help prevent gouges. take your time here. gentle is better.
removal of sealant
scotch bright disks work great. wear a mask. and realodine after done.
tank testing, quick easy and cheap
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a loop with three feet high on both sides
add nitrogen until the water is four feet higher on one side then the other. you now have 2 psi in the tank. care should be taken here, fill slowly.
spray the seams with soapy water and look for bubbles. use hand soap or aircraft soap, some soaps are bad for alum.
how to find that damn mystery leak i have tried everything else.
sometimes really small leaks are the worse to find, but one way to track them down is to apply dye-pen developer to the outside of the tank it will show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
Be a better friend, newshound, and
| Quote: | | http://www.matronics.com/contribution t="_blank">http://www.matronics.com/Navigator?RV-List a>http://forums.matronics.com Be a better friend, newshound, and |
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chaskuss(at)yahoo.com
Guest
|
| Posted: Wed May 07, 2008 1:39 pm Post subject: Proseal remover? |
|
|
Jan,
The difference between "clear" and "gold" Alodine (or Iridite) is only cosmetic. They add a dye to the "gold" to aid you in knowing when the chromic conversion process has completed. I just did a quick search regarding the application of Pro-Seal or Chem Seal (as supplied by Vans)
Here is what I found.
http://www.aviationproductsinc.com/Publications/TDS_PDF/TDS_CS3204.pdf
http://corporateportal.ppg.com/NR/rdonlyres/22FFA52B-AC2C-4D75-AE20-08E03ACF8EB8/0/asaguide.pdf
Both simply stress that the surface be clean.
I only know of several sets of fuel tanks which were built locally, which were Alodined prior to sealing. No one has had any sealing problems so far.
Charlie Kuss
--- On Wed, 5/7/08, jan <jan(at)claver.demon.co.uk> wrote:
| Quote: | From: jan <jan(at)claver.demon.co.uk>
Subject: RE: Proseal remover?
To: rv-list(at)matronics.com
Date: Wednesday, May 7, 2008, 1:22 PM
Hi Richard, (nothing wrong with perfection ..  ...)
& Charles
Is the reason for using clear and gold Alodine purely
esthetic or is there a
technical (chemical) reason why they are use on different
parts of the
aircraft (at Boeing) ? I have used the "gold"
Alodine quite a lot - prior to
painting ... on several parts of the RV I am building.
Especially the spar.
>From a adhesion point - paint does stick very well to a
Alodined surface -
Does the maker of ProSeal have any official policy on using
Alodine prior to
application of its product?
Do you know "how many / how widely" the practice
of alodining the inside of
the tanks are ??
Jan
_____
From: owner-rv-list-server(at)matronics.com
[mailto:owner-rv-list-server(at)matronics.com] On Behalf Of
RICHARD MILLER
Sent: 07 May 2008 00:22
To: rv-list(at)matronics.com
Subject: Re: Proseal remover?
hi guys
jan i was taught to be a litle anal retentive and by
the way had to
follow boeing spec's so everything gets alodined. clear
for skins and gold
for every thing else. besides i like the color. and water
from bad fuel is
bad for alum tanks.
larry if they don't leak now why play with it. but when
they start to leak
change them out when you pull the tank. it should only take
about an hour
per tank.
about fuel filters, airflow performance has a filter prior
to the twin pump
setup it will stop any thing big enough to damage the
pumps, but, big but,
do you want to risk your bird on one fuel filter. install
one filter per
tank prior to the selector valve. and sleep better at
night. remember the
airflow system much more pressure then a carb. i have never
like the one
filter idea in certified aircraft. maybe i should apply for
an stc for two.
airflow fuel filters are an annual replacement item,
don't cheat
Larry Bowen <larry(at)bowenaero.com> wrote:
FYI, I used domed nut plates on my RV-8 tanks....and had to
cut a couple of
them off because they interfered with the fuel pick-up.
Sometimes
second-guessing uncle Van doesn't pay off....
--
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com <http://bowenaero.com/>
On Tue, May 6, 2008 at 2:14 PM, jan
<jan(at)claver.demon.co.uk
<mailto:jan(at)claver.demon.co.uk> > wrote:
Hi Richard,
I will be doing my hand build tanks later on this summer. I
have read your
article with great interest. First ... I have bought the
domed nut plates...
they are used on commercial planes from what I understand
... and should
make a perfect seal with a "O" ring .. Then cover
the nut plate after
fitting with pro-seal as a extra safeguard against leaks.
Do you recommend alodining the tank skin and the ribs ??
That is a new one
to me ... I thought cleaning with Aluprep ...rinse with
water ... and scuff
the seams is fine ??
Appreciate you comments on this
Best regards
Jan
_____
From: owner-rv-list-server(at)matronics.com
<mailto:owner-rv-list-server(at)matronics.com>
[mailto:owner-rv-list-server(at)matronics.com
<mailto:owner-rv-list-server(at)matronics.com> ] On
Behalf Of RICHARD MILLER
Sent: 06 May 2008 14:54
To: rv-list(at)matronics.com
<mailto:rv-list(at)matronics.com>
Subject: Re: Proseal remover?
Since we seem to have so many complaints about fuel leaks,
lets cover fuel
tank 101.
static loads on a fuel tank are less then .5 psi. duct tape
can hold .5 psi.
dynamic loads are variable due to high g loading and can
reach 4
psi, with tank destruction emanate. the problem with
checking tanks is the
static pressure loading is applied to all surfaces and they
need to be
stressed to handle that load. most are not ie, the caps.
next problem is the inherent movement of the structure as
it flexes. tearing
the sealant bonds.
so lets assume that you built it close to right and now
want to test it.
water, fuel, any material with the exception of the
original sealant will
contaminate the joint during testing. so how do we remove
the contaminates?
we don't contaminate in the first place. the sealants
we are using are
sensitive to contaminates so air or better nitrogen is the
testing medium of
choice.
after inspecting aircraft with properly applied pro-seal
that had over
twenty years in service, the stuff sticks. sloshing does
not work and will
result in a crash, the unfortunate part of this is that the
pilot is always
the first person at the crash site.. fire and medic support
might take a
little longer arriving. do not slosh tanks
types of leaks.
seam leaks, very rare, normally caused by poor
construction, or extreme g
loading.
fastener leaks, more common also caused by high g loading
and flexing of the
structure, compounded but poor sealing practices. all tank
fasteners are to
be installed wet. and then sealed on the inside.
access plate/fitting leaks, most common. cause improperly
applied sealant,
wrong nut plates , they should be all domed and sealed. too
long of screw
that goes through the nut plate dome. bad gaskets, failed
orings. rotation
of a fitting after sealant has dried. always use two
wrenches when removing
lines.
the primary problem with tank repair is the lack of
structural integrity of
this tank. riveted tanks and the repair tricks where
designed around the
larger transport type aircraft. pro-seal sticks well and
can be a problem to
break the seams apart without disturbing/destroying the
structure.
the best way that i have found to stop small leaks at
fasteners and seams is
to apply a heavy vacuum to the outside of the tank at the
effected area to
draw any remaining fuel out and and suck the sealant in to
the void.
additional rivets added along seam lines while still wet
helps to.
sealant application tricks.
clean /clean /clean. pro-seal dose not like oil and most
primers but loves a
good cleaned alodined surface.
mechanical grip/ light scuff on a flaying surface helps
with adhesion
tape applied along side the joints to assist with clean up
gloves, this stuff does not like to come off and mek is bad
for you
proper fit of parts, don't expect pro-seal to fill
gaps.
don't use to much. or you will get a wavy structure.
use type a for seams it helps with waves and type b for
fillets and fastener
sealing
don't exceed the pot life
mix it right and use the correct proportions a good scale
really helps.
use the longest pot life you can, i have found that 1/2
stuff to be almost
useless for most jobs.
the proper place for sealant is on the inside of the tank
not globed on the
outside beside it looks ugly.
tips of opening seams
sharpend putty knives are great but be sure to round the
corners to help
prevent gouges. take your time here. gentle is better.
removal of sealant
scotch bright disks work great. wear a mask. and realodine
after done.
tank testing, quick easy and cheap
connect air/nitrogen supply to vent
connect clear hose to drain about ten feet worth
loop hose to floor and fill with water until you have a
loop with three feet
high on both sides
add nitrogen until the water is four feet higher on one
side then the other.
you now have 2 psi in the tank. care should be taken here,
fill slowly.
spray the seams with soapy water and look for bubbles. use
hand soap or
aircraft soap, some soaps are bad for alum.
how to find that damn mystery leak i have tried everything
else.
sometimes really small leaks are the worse to find, but one
way to track
them down is to apply dye-pen developer to the outside of
the tank it will
show up any tiny leaks. over a couple of days.
and this ends fuel tank 101 hope it helps.
rick miller
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