Author: "Hugh Tyler (SBI-Chico)" <hugh@...> Time: Thu Sep 19, 2002 8:33 am PDT Link
I am in the process of testing the tank on my first wing. I first put the
tank under a little pressure and slathered soapy water over everything. No
bubbles, great no big leaks! I then marked the water level on the manometer
before calling it a night. A few minutes later I realized that I had left my
glasses in the garage. I just happened to look at the water level and it was
3/4 of an inch above my bench mark line. The next morning it was 3-4 inches
below, that afternoon 3-4 inches above, you get the idea. This has been
going on for 36 hours now.
I expected some variation in the water level due to temp changes but nothing
like this, I don't believe I could catch a pinhole leak with such a
temperamental test. What else can I do to convince myself that the tank is
leak free? Thanks.
Hugh
Author: "Michael Stewart" <mstewart@...> Time: Thu Sep 19, 2002 10:58 am PDT Link
Hi Hugh,
Got a simpe solution for ya.
Blow up a ballon and put it over your fitting. A ballon puts about
2lbs of air pressure, a perfect amount for testing.
You can read details on my web site. Look in the uttos section. I had
leaks.
http://www.mstewart.net/michael/rv/index.htm
Then just use soapy water spray method to find the leaks.
Works great, and cheap. Oh and BTW, the ballon work good for pitot
leaks too.
See ya.
Mike Stewart
--- In vansairforce@y..., "Hugh Tyler (SBI-Chico)" <hugh@b...> wrote:
> I am in the process of testing the tank on my first wing. I first
put the
> tank under a little pressure and slathered soapy water over
everything. No
> bubbles, great no big leaks! I then marked the water level on the
manometer
> before calling it a night. A few minutes later I realized that I
had left my
> glasses in the garage. I just happened to look at the water level
and it was
> 3/4 of an inch above my bench mark line. The next morning it was 3-
4 inches
> below, that afternoon 3-4 inches above, you get the idea. This has
been
> going on for 36 hours now.
>
> I expected some variation in the water level due to temp changes
but nothing
> like this, I don't believe I could catch a pinhole leak with such a
> temperamental test. What else can I do to convince myself that the
tank is
> leak free? Thanks.
>
> Hugh
Author: TColeE@... Time: Thu Sep 19, 2002 10:58 am PDT Link
Hugh: Try this .Put a couple of gal of gas inthe tank Put some food
coloring in it. Set it in the sun with the cap on and keep moving it arround.
Pressuer will build up and if it leaks the food coloring will stain the one
rivet that did not seal. Worked for me. I know.
Terry E. Cole
Author: "Rick Galati" <rick07x@...> Time: Thu Sep 19, 2002 10:58 am PDT Link
..................I don't believe I could catch a pinhole leak with
such a temperamental test. What else can I do to convince myself that
the tank is leak free? Thanks. Hugh
You can try what I and quite a few other builders have done. First,
insure that the filler cap, and all other openings from the tank are
sealed as tight as practical. Then I fabbed a tee to the tank drain
using titeseal on the threads, a toy balloon on one side and an air
valve on the other side of the tee. Using a bicycle pump to
pressurize the balloon (and the tank), I figured that if the balloon
could hold air for several hours, the tank should hold fluid. Keep in
mind though, that your average toy balloon will naturally lose some
air over an extended period of time. A word of caution. Do not over
pressurize! You can easily split your tank wide open with a lot less
pressure than you may realize.
Author: Jaye and Scott Jackson <jayeandscott@...> Time: Thu Sep 19, 2002 10:58 am PDT Link
Sounds like you've just manufactured a barometer....
Scott in Vancouver
----- Original Message -----
From: "Hugh Tyler (SBI-Chico)" <hugh@b...>
To: <vansairforce@yahoogroups.com>
Sent: Thursday, September 19, 2002 7:58 AM
Subject: [VAF Mailing List] bubbles, tubes, and tank testing
> I am in the process of testing the tank on my first wing. I first put the
> tank under a little pressure and slathered soapy water over everything. No
> bubbles, great no big leaks! I then marked the water level on the
manometer
> before calling it a night. A few minutes later I realized that I had left
my
> glasses in the garage. I just happened to look at the water level and it
was
> 3/4 of an inch above my bench mark line. The next morning it was 3-4
inches
> below, that afternoon 3-4 inches above, you get the idea. This has been
> going on for 36 hours now.
>
> I expected some variation in the water level due to temp changes but
nothing
> like this, I don't believe I could catch a pinhole leak with such a
> temperamental test. What else can I do to convince myself that the tank is
> leak free? Thanks.
>
> Hugh
> Online help on this group at:
> http://help.yahoo.com/help/groups/
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Author: "Larry Perryman" <larry.perryman@...> Time: Thu Sep 19, 2002 4:08 pm PDT Link
Hugh,
You are absolutely leak free. The cycling you are seeing is caused by
variances in temperature and atmospheric pressure. If you had even a
small pin hole leak, the manometer would not hold for 15 minutes much
less 36 hours. This is basicly the test used to test natural gas
pipes. They use 1 psi for 24 hours. Since an air molecule is a lot
smaller than a an AV Gas molecule, if it is holding air, it will hold
gas.
Don't wory about little ups and downs. If it will hold a difference
in levels for 12 hours, Go on to the next one.
Regards
Larry Perryman
N194DL
Waiting for a good weather day for first flight.
Author: "dnbarrie11" <ktlkrn@...> Time: Thu Sep 19, 2002 4:08 pm PDT Link
Aerocompinc. uses a simple method for leak detection in the tanks of
their composite planes. They simply attach a fitting to the tank
(usually the fuel fitting that is going to be used) and a piece of
rubber line. The tank is pressurized by blowing in the tube and then
hooking to an altimeter. The altimeter is set to say 1000' and the
tank is left over night. If there is a change there is a leak. It has
worked for them for years.
Darwin N. Barrie
Chandler AZ
--- In vansairforce@y..., "Hugh Tyler (SBI-Chico)" <hugh@b...> wrote:
> I am in the process of testing the tank on my first wing. I first
put the
> tank under a little pressure and slathered soapy water over
everything. No
> bubbles, great no big leaks! I then marked the water level on the
manometer
> before calling it a night. A few minutes later I realized that I
had left my
> glasses in the garage. I just happened to look at the water level
and it was
> 3/4 of an inch above my bench mark line. The next morning it was 3-
4 inches
> below, that afternoon 3-4 inches above, you get the idea. This has
been
> going on for 36 hours now.
>
> I expected some variation in the water level due to temp changes
but nothing
> like this, I don't believe I could catch a pinhole leak with such a
> temperamental test. What else can I do to convince myself that the
tank is
> leak free? Thanks.
>
> Hugh
Author: Bobby Hester <bhester@...> Time: Thu Sep 19, 2002 4:08 pm PDT Link
"Hugh Tyler (SBI-Chico)" wrote:
> I am in the process of testing the tank on my first wing. I first put the
> tank under a little pressure and slathered soapy water over everything. No
> bubbles, great no big leaks! I then marked the water level on the manometer
> before calling it a night. A few minutes later I realized that I had left my
> glasses in the garage. I just happened to look at the water level and it was
> 3/4 of an inch above my bench mark line. The next morning it was 3-4 inches
> below, that afternoon 3-4 inches above, you get the idea. This has been
> going on for 36 hours now.
>
> I expected some variation in the water level due to temp changes but nothing
> like this, I don't believe I could catch a pinhole leak with such a
> temperamental test. What else can I do to convince myself that the tank is
> leak free? Thanks.
>
> Hugh
I checked mine the same way you can read about it at the bottom of this page:
http://www.geocities.com/hester-hoptown/RVSite/FuelTankAssy.html
I am convinced I have no leaks!
--
Surfing the Web from Hopkinsville, KY
Visit my web site at: http://www.geocities.com/hester-hoptown/RVSite/
RV7A Working on the wings :-)
Author: "Anderson, William" <wanderson@...> Time: Fri Sep 20, 2002 10:49 am PDT Link
FWIW, a 4" positive to 4" negative variation in water level is only 0.28
psi fluctuation in pressure.
-----Original Message-----
From: Bobby Hester [mailto:bhester@a...]
Sent: Thursday, September 19, 2002 5:45 PM
To: vansairforce@yahoogroups.com
Subject: Re: [VAF Mailing List] bubbles, tubes, and tank testing
"Hugh Tyler (SBI-Chico)" wrote:
> I am in the process of testing the tank on my first wing. I first put the
> tank under a little pressure and slathered soapy water over everything. No
> bubbles, great no big leaks! I then marked the water level on the
manometer
> before calling it a night. A few minutes later I realized that I had left
my
> glasses in the garage. I just happened to look at the water level and it
was
> 3/4 of an inch above my bench mark line. The next morning it was 3-4
inches
> below, that afternoon 3-4 inches above, you get the idea. This has been
> going on for 36 hours now.
>
> I expected some variation in the water level due to temp changes but
nothing
> like this, I don't believe I could catch a pinhole leak with such a
> temperamental test. What else can I do to convince myself that the tank is
> leak free? Thanks.
>
> Hugh
I checked mine the same way you can read about it at the bottom of this
page:
http://www.geocities.com/hester-hoptown/RVSite/FuelTankAssy.html
<http://www.geocities.com/hester-hoptown/RVSite/FuelTankAssy.html>
I am convinced I have no leaks!
--
Surfing the Web from Hopkinsville, KY
Visit my web site at: http://www.geocities.com/hester-hoptown/RVSite/
<http://www.geocities.com/hester-hoptown/RVSite/>
RV7A Working on the wings :-)
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Author: johncclarkva@... Time: Mon Sep 23, 2002 5:34 am PDT Link
Just went through the same thing with an "up and down" water manometer.
Tried to find the effects temp and press on the water level. I am a little
rusty but I think 1 degF will move the water about 0.8 inches. A 0.10
change in the pressure (such as 29.92 to 29.82) will move the water about 1.4
inches. Just for fun and games, you could keep adjusting an altimiter to a
constant altitude and keep track of the changes in the Kollsman setting.
[Non-text portions of this message have been removed]