sealing gas lines on I/O gas tank fill?

Russ Preves

Seaman
Joined
Apr 14, 2009
Messages
65
I was looking at my 30 year old gas fill hose where it goes into the tank at in the bilge....and it looks like in addition to two hose clamps...there's some kind of sealant.....

any suggestions as what sealant...if any.....to use now with the new hose?

Thanks,

Russ
 

EddiePetty

Lieutenant Junior Grade
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Aug 25, 2008
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1,008
Re: sealing gas lines on I/O gas tank fill?

That's probably not sealant but 30 years of hose deterioration, especially since the inclusion of alcohol in our fuel.

If your USCG approved replacement hose is as stiff and wire inserted as the hose I recently installed on our V-20,
A little slick'em really helped to insert the hose over the barb.

As a side note; on the fill end, ensure that your fill port is properly grounded. :)
 

Russ Preves

Seaman
Joined
Apr 14, 2009
Messages
65
Re: sealing gas lines on I/O gas tank fill?

That's probably not sealant but 30 years of hose deterioration, especially since the inclusion of alcohol in our fuel.

If your USCG approved replacement hose is as stiff and wire inserted as the hose I recently installed on our V-20,
A little slick'em really helped to insert the hose over the barb.

As a side note; on the fill end, ensure that your fill port is properly grounded. :)

Thanks for your reply...but I don't think there's any barbs....this hose is 1 1/2 or 2 inches, and I think it fits over the fill neck on this aluminum tank...no barbs....
 

EddiePetty

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Re: sealing gas lines on I/O gas tank fill?

Thanks for your reply...but I don't think there's any barbs....this hose is 1 1/2 or 2 inches, and I think it fits over the fill neck on this aluminum tank...no barbs....


Same size.....perhaps I should have said 'hose bib' ! :joyous
 

UncleWillie

Captain
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Oct 18, 2011
Messages
3,995
Re: sealing gas lines on I/O gas tank fill?

I have a boat that was built this year. (2012)
The fuel fill hose is double clamped and glued; It is only coming off if you cut it off.

You are looking for Permatex Aviation Form A Gasket #3;
Available at most Autoparts Stores.

You can also find it in the NAPA house brand.
 

Russ Preves

Seaman
Joined
Apr 14, 2009
Messages
65
Re: sealing gas lines on I/O gas tank fill?

I have a boat that was built this year. (2012)
The fuel fill hose is double clamped and glued; It is only coming off if you cut it off.

You are looking for Permatex Aviation Form A Gasket #3;
Available at most Autoparts Stores.

You can also find it in the NAPA house brand.

Thanks for that...I, of course, think any gas line in the bilge should have sealant....but what's interesting...TWO boat places I called today said....NAH you don't need it...just use two hose clamps....

....bet they check for leaks with a match, too....
:)
 

skyking897

Petty Officer 1st Class
Joined
Mar 21, 2010
Messages
208
Re: sealing gas lines on I/O gas tank fill?

I replaced the original fill hoses on my 26 year old Sylvan this past spring. There was no sealant on the fill tube but the hoses were stuck on and I had to cut them off. I just used some lube on the hose to push over the flared end ( kind of bubbled out) of the fill tube and used new stainless clamps (double clamped as before). I can't see why you would need sealant. If the double clamps don't seal it there must be a problem.
 

Outsider

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Apr 24, 2007
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1,022
Re: sealing gas lines on I/O gas tank fill?

..bet they check for leaks with a match, too.

You seem awfully convinced being as you didn't know what you were looking at. If two hose clamps don't get it, it's highly unlikely sealant will, either, but I'm willing to learn. what sealant would you use ... :confused:
 

UncleWillie

Captain
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Messages
3,995
Re: sealing gas lines on I/O gas tank fill?

I am surprised that many do not consider two clamps overkill to begin with.
"If one clamp won't seal it, something is wrong", would be the expected response.

Two clamps Plus Form a gasket Sealant appears to be the norm on many tanks.

If you are going to do, then do it right; Then Overdo it! :rolleyes:
 

frantically relaxing

Senior Chief Petty Officer
Joined
Nov 19, 2011
Messages
699
Re: sealing gas lines on I/O gas tank fill?

Actually, when it comes to boats, I believe 2 clamps is required by regulation on virtually any hose WITH a clamp.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,320
Re: sealing gas lines on I/O gas tank fill?

Hose to bib connections are compression seals and thus do not require a sealer. If you see some type of a material on the existing connection it's a hose lubricate used during assembly.

As for the one or two clamp? Federal law says two ;)

FEDERAL LAW
183.564 - Fuel tank fill system

(b) Each hose in the tank fill system must be secured to a pipe, spud, or hose fitting by:

(1) A swaged sleeve;
(2) A sleeve and threaded insert; or
(3) Two adjacent metallic hose clamps that do not depend solely on the spring tension of the clamps for compressive force.



Fuel tank fill system hose connections shall be made to a pipe (smooth pipe is acceptable), a spud or a hose fitting. The hose connections may be made by one of the following means:

(a) Swaged Sleeve: This type of connection is usually made by the supplier of a hose assembly, since special machinery or apparatus is necessary to perform the swaging operation. The attachment to the fuel system is usually made by means of a threaded hose fitting.

(b) Sleeve and Threaded Insert: This type of connection usually can be made by an installer using normal shop tools. Usually the sleeve is placed on the outside of the hose and the threaded insert screwed into the inside of the hose and sleeve. There are connections in which the sleeve is installed on the hose after the insert is installed. The attachment to the fuel system is usually made by means of a threaded hose fitting.

(c) Two Adjacent Metallic Hose Clamps That Do Not Depend Solely On The Spring Tension Of The Clamps For Compressive Force: For a fuel tank fill line, 2 hose clamps are usually slipped on each end of the hose in a loosened condition, the hose installed and the hose clamps tightened. The attachment to the fuel system is usually made by means of a beaded, flared or serrated spud, pipe or hose fitting. Hose clamps are to be installed side by side, not on top of each other. Two clamps are required for mechanical strength and to resist any tendency for the hose to twist.NOTES:

1.Spring wire and other type clamps that depend on the spring tension properties of the clamp material are prohibited from use on fuel line installations on boats.
2.Wire type hose clamps are not acceptable.

http://www.uscgboating.org/regulations/boatbuilder_s_handbook/fuel_standards_partg.aspx]
 

Outsider

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1,022
Re: sealing gas lines on I/O gas tank fill?

Uhhh, I believe what you're pasting are manufacturing regs. While it may be hard to argue the value of those, they do not restrict owners once the boat has left the factory. At least that's how I understand it. I used the analogy of two clamps because that's what the OP said he had ... ;)
 

UncleWillie

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Oct 18, 2011
Messages
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Re: sealing gas lines on I/O gas tank fill?

... If you see some type of a material on the existing connection it's a hose lubricate used during assembly.

My recently manufactured boat (Feb 2012) has TWO hose clamps and a Dark Red sealing material on them.
The same material can be seen on all the threaded fuel fittings.

I attempted to remove the fill hose in an attempt to drain the fuel tank for the winter;
It absolutely was not coming off short of splitting the hose.
This is not a lubricant by any means!
It is harder than RTV silicon but a little softer than Hot Melt Glue.

There is no requirement to apply a sealant to the double clamped hose fittings.
I think the manufacturer finds that it act like a lubricant while it is still liquid and as long as they already have the bottle open to seal the threaded fittings, it naturally finds use in installing the fill hose.

There is nothing wrong with overdoing it!
 

OllieC

Chief Petty Officer
Joined
Dec 8, 2011
Messages
535
Re: sealing gas lines on I/O gas tank fill?

You mean like the stuff that is on this connector? This is my fuel line coming into the pump. I have no idea what it is? Plumber putty?
 

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Home Cookin'

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Re: sealing gas lines on I/O gas tank fill?

One thing about sealing I was told is not to use plumber's tape b/c gas melts it and it ends up in your jets, but blue pipe dope is OK.
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
Re: sealing gas lines on I/O gas tank fill?

You mean like the stuff that is on this connector? This is my fuel line coming into the pump. I have no idea what it is? Plumber putty?

Well that does look like regular pipe dope.
It doesn't make any sense however, because it is a flared compression fitting and the threads only apply the compression force and have nothing to do with the actual "Sealing".

We are tahking about the Reddish Seal A Gasket material seen on these hoses.


FuelVentSeal1.jpg FuelFillSeal1.jpg
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
Re: sealing gas lines on I/O gas tank fill?

One thing about sealing I was told is not to use plumber's tape b/c gas melts it and it ends up in your jets, but blue pipe dope is OK.



Plumbers tape is Teflon and does not melt in gasoline.
But that's the problem, if a small shred gets loose it will plug up the jets.
Anything that melts/dissolves in fuel will eventually dissolve and leak.

Pipe dope tends to harden and stay in where it belongs.
Unless it is specifically recommended for use with fuel systems I would still avoid it.
Most plumbing products are waterproof but not necessarily fuel proof.
 

cyclops2

Banned
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Apr 19, 2011
Messages
1,237
Re: sealing gas lines on I/O gas tank fill?

Post # 11 is good as Gold.

If you can put 2 NARROWER CLAMPS ON ? Do it. Still a very safe proven way. No grit of glues to get into the fuel system.

NEVER PUT ANY glues on the inside of any hose............It gets pushed further into the hose lining out of sight & washes into all the fuel system.

Takes a while . But REALLY screws up everything forever. Most mechanics will take forever to figure that one out..........Always put liquids on the outside of the pipes.
 

OllieC

Chief Petty Officer
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Dec 8, 2011
Messages
535
Re: sealing gas lines on I/O gas tank fill?

10-4 . I took that picture this Fall while trying to build a 6 gallon MPI fogging cocktail for the 5.0. I noticed the stuff on there, was curious, but it didn't look like it was doing anything to prevent leaks. We'll know this Spring....(which can't come fast enough):grumpy:
 
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