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[GMCnet] LPG Tank Refinishing [message #122722] Fri, 22 April 2011 08:39 Go to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

Yesterday I finished up repainting the LPG tank out of Double Trouble and
cleaning up the galvanized compartment it sits in.

I used a soda blaster I got from Harbor Freight to remove the old paint and
loose rust; it worked well.

The instructions that came with the soda blaster noted that it could
generate sparks so to be safe; I purged the tank with shop air for about 5
minutes. I noted the smell of Mercaptan decreased greatly after the purge so
I figured it was safe to proceed and since I am sitting here typing this
obviously I was correct. ;-)

When I removed the gage I noted that the O-ring around the LPG gage sealing
boss was pretty hard.

The o-ring has a square cross section but all I could find were round cross
section o-rings at the local True Value hardware store so I got several
different sizes. They were the typical black material but the box did not
say what the material was.

I put the one with the smallest cross section around the gage float sealing
boss and it looked pretty close to the original o-ring so I installed it.

After applying a bit of anti-seize to the screws I tightened them lightly
until they made contact with the gage face.

From there I screwed them down slowly and sequentially so that it would pull
the gage in straight.

Questions:

1) Is the o-ring a supposed to be a special material?

2) Does anyone know where I can get the correct square cross section o-ring
for the LPG tank gage boss?

John Sharpe mentioned to me that I need to evacuate the cylinder to get the
air out so I did a Google search and found the article below.

http://tinyurl.com/cd36x

http://home.earthlink.net/~derekgore/rvroadiervfulltimingwhatisitreallylike/
id45.html

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] LPG Tank Refinishing [message #122728 is a reply to message #122722] Fri, 22 April 2011 09:10 Go to previous messageGo to next message
gmcrv1 is currently offline  gmcrv1   United States
Messages: 839
Registered: August 2007
Location: Memphis
Karma: -1
Senior Member
Rob,

I would try one of those propane supplier/distributors. The ones that have
the huge mega gallon tanks behind their small offices that usually display
household appliances. Or try googling for parts.

Hope all is well,

Tom Eckert N2VWN
73 Glacier
Oakland, TN




On Fri, Apr 22, 2011 at 8:39 AM, Rob Mueller <robmueller@iinet.net.au>wrote:

> G'day,
>
> Yesterday I finished up repainting the LPG tank out of Double Trouble and
> cleaning up the galvanized compartment it sits in.
>
> I used a soda blaster I got from Harbor Freight to remove the old paint and
> loose rust; it worked well.
>
> The instructions that came with the soda blaster noted that it could
> generate sparks so to be safe; I purged the tank with shop air for about 5
> minutes. I noted the smell of Mercaptan decreased greatly after the purge
> so
> I figured it was safe to proceed and since I am sitting here typing this
> obviously I was correct. ;-)
>
> When I removed the gage I noted that the O-ring around the LPG gage sealing
> boss was pretty hard.
>
> The o-ring has a square cross section but all I could find were round cross
> section o-rings at the local True Value hardware store so I got several
> different sizes. They were the typical black material but the box did not
> say what the material was.
>
> I put the one with the smallest cross section around the gage float sealing
> boss and it looked pretty close to the original o-ring so I installed it.
>
> After applying a bit of anti-seize to the screws I tightened them lightly
> until they made contact with the gage face.
>
> From there I screwed them down slowly and sequentially so that it would
> pull
> the gage in straight.
>
> Questions:
>
> 1) Is the o-ring a supposed to be a special material?
>
> 2) Does anyone know where I can get the correct square cross section o-ring
> for the LPG tank gage boss?
>
> John Sharpe mentioned to me that I need to evacuate the cylinder to get the
> air out so I did a Google search and found the article below.
>
> http://tinyurl.com/cd36x
>
>
> http://home.earthlink.net/~derekgore/rvroadiervfulltimingwhatisitreallylike/
> id45.html
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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Re: [GMCnet] LPG Tank Refinishing [message #122730 is a reply to message #122722] Fri, 22 April 2011 09:26 Go to previous messageGo to next message
PettyVTX is currently offline  PettyVTX   United States
Messages: 363
Registered: April 2011
Location: Winder Ga.
Karma: 1
Senior Member
Robert be carefull LP O-Rings are a special material.
We use a lot of O-Rings on out lp tanks for forklifts and they are squared type. But i do know they are SPECIAL we tried regular rings and they disentegrated very quickly. you can get the rings from Amerigas or a lp supplier. some times from an appliance dealer that sells LP stoves.I will look here at the shop and see if we have any laying aroud maybe i can send you one.dont know how fast you have to have one. I will let you know
Ted


Ex Avion now looking for a 23' Jeep Wrangler Towd
Re: [GMCnet] LPG Tank Refinishing [message #122766 is a reply to message #122722] Fri, 22 April 2011 12:36 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
Messages: 2446
Registered: January 2004
Karma: 5
Senior Member
Rob,
The gauge assembly is made by Rochester Gauges.

This may be close. The gasket material is Buna-N as standard which is
black in color.

http://www.rochestergauges.com/Pages/PDFs/6200.pdf

You could contact them direct or this supplier

http://www.gasequipment.com/newgas/index.html

Regards,

J.R. Wright
GMC GreatLaker
TZE Zone Restorations
77 Eleganza Custom (Sold)
78 Transmode Custom (Purchase Pending)
1975 Avion (Under Reconstruction)
Michigan

On Apr 22, 2011, at 9:39 AM, Rob Mueller wrote:

> G'day,
>
> Yesterday I finished up repainting the LPG tank out of Double
> Trouble and
> cleaning up the galvanized compartment it sits in.
>
> I used a soda blaster I got from Harbor Freight to remove the old
> paint and
> loose rust; it worked well.
>
> The instructions that came with the soda blaster noted that it could
> generate sparks so to be safe; I purged the tank with shop air for
> about 5
> minutes. I noted the smell of Mercaptan decreased greatly after the
> purge so
> I figured it was safe to proceed and since I am sitting here typing
> this
> obviously I was correct. ;-)
>
> When I removed the gage I noted that the O-ring around the LPG gage
> sealing
> boss was pretty hard.
>
> The o-ring has a square cross section but all I could find were
> round cross
> section o-rings at the local True Value hardware store so I got
> several
> different sizes. They were the typical black material but the box
> did not
> say what the material was.
>
> I put the one with the smallest cross section around the gage float
> sealing
> boss and it looked pretty close to the original o-ring so I
> installed it.
>
> After applying a bit of anti-seize to the screws I tightened them
> lightly
> until they made contact with the gage face.
>
> From there I screwed them down slowly and sequentially so that it
> would pull
> the gage in straight.
>
> Questions:
>
> 1) Is the o-ring a supposed to be a special material?
>
> 2) Does anyone know where I can get the correct square cross section
> o-ring
> for the LPG tank gage boss?
>
> John Sharpe mentioned to me that I need to evacuate the cylinder to
> get the
> air out so I did a Google search and found the article below.
>
> http://tinyurl.com/cd36x
>
> http://home.earthlink.net/~derekgore/rvroadiervfulltimingwhatisitreallylike/
> id45.html
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: [GMCnet] LPG Tank Refinishing [message #122773 is a reply to message #122722] Fri, 22 April 2011 13:29 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
Senior Member
Rob
From what I understand it is indeed special material. In 2001 when I moved to cold country from Los Angeles my propane tank started pouring liquid propane from that O ring at 1 AM (15 degrees) in a camp ground. After I managed to expell all the propane in the tank I took the old O ring to a local propane co. They had the proper replacement O ring. It has been fine since then.

Roy


Roy Keen Minden,NV 76 X Glenbrook
Re: [GMCnet] LPG Tank Refinishing [message #122785 is a reply to message #122722] Fri, 22 April 2011 14:23 Go to previous messageGo to next message
hasbeen is currently offline  hasbeen   United States
Messages: 66
Registered: August 2005
Location: Cave Creek, AZ
Karma: 0
Member
G'day Rob, I have the LP purging kit and more than likely have a seal for that gauge if you do not find one. I just don't know how I can get you this kit to use. If it came down to it I guess we could take pictures and you could try and make one up there. Let me know if I can help, Jim
Re: [GMCnet] LPG Tank Refinishing [message #122832 is a reply to message #122785] Fri, 22 April 2011 21:07 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

Thanks to all the respondents!

Today John Sharpe and I evacuated the LPG cylinder to 28 in hg using his air
conditioning system vacuum pump and charging gage set.

We let it sit at vacuum a good hour or more. We then connected a BBQ bottle
to the LPG tank outlet valve through a regulator. I opened the valve on the
BBQ bottle and barely cracked the valve on the LPG tank. You could hear the
gas transferring from the BBQ bottle to the LPG tank. It took quite awhile
for the hissing to stop. When it did I removed the knurled vent screw, wet
my fingers, and could feel flow coming out of the bottle. A few seconds
later I KNEW it was filled with LPG as I could smell the Mercaptan.

I MUST leave for Bean Station on Monday but I'll contact Rochester Gage and
see where I can get the correct gasket / seal along my route.

Tomorrow I'm going to have a small amount of LPG put in the tank to make
sure I don't have any leaks and so I can run the fridge while under way
during the day.

When I get the correct gage gasket I'll dump the LPG and install it.

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] LPG Tank Refinishing [message #122836 is a reply to message #122832] Fri, 22 April 2011 21:53 Go to previous message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Rob,

Just wait 'til you fill that tank! I stopped at Camping World in Byron, GA
today after my usual source in Americus was closed. I expected to take
almost a full tank, 6 gallons. Thank goodness I didn't: 3.6 gallons cost
$14.96!

Ken H.

On Fri, Apr 22, 2011 at 10:07 PM, Rob Mueller <robmueller@iinet.net.au>wrote:

> G'day,
>
> Thanks to all the respondents!
>
> Today John Sharpe and I evacuated the LPG cylinder to 28 in hg using his
> air
> conditioning system vacuum pump and charging gage set.
> ...
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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