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Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 10:17 am
by c130king
Fellow Mac Modifiers,

I have a new 12-gal tank and I have taken the fuel sender off of my old tank and am installing it on my new fuel tank. The unit includes a rubber/plastic gasket that sits over the hole drilled in the top of the tank.

The hole is about 1.75 inches in diameter. Above this hole sits the gasket which is probably 2.5 inches in diameter. This gasket has 5 holes where the self tapping screws go to secure the unit to the tank. Above this gasket sits the top of the sender unit and it has the same holes in its plate for the screws.

I don't have the instructions for this sender unit but it seems to me that when it was installed the first time by the original owner there was some sort of sealant when it was installed. There is residue of the sealant on the gasket.

Does anyone have any idea what type of sealant may be appropriate to seal this gasket to the tank and probably between the gasket and the sender unit?

Thanks,
Jim

On Edit: Adding some pics:

Here is a pic of the broken filler neck on my original tank (6 year old tank)
Image

This shows where the fuel line runs under the cockpit...between cockpit and inner line. Electrical line is the cable between fuel sender and fuel gauge on pedestal.
Image

And here is the new tank and you can see the gasket (leaning on the sanding block) and the fuel sender.
Image

Re: Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 10:48 am
by Bleakco
I have used permatex #2 in similar cases and it sticks to the plastic and will not react with gas...

Re: Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 11:19 am
by c130king
Where can one get Permatex #2?

Thanks,
Jim

Re: Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 11:40 am
by Hamin' X
Any auto parts store will have it, Jim.

~Rich

Re: Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 12:59 pm
by c130king
Hamin' X wrote:Any auto parts store will have it, Jim.

~Rich

Thanks.

Re: Sealant on a Fuel Tank

Posted: Sat Nov 12, 2011 2:31 pm
by K9Kampers
c130king wrote:Where can one get Permatex #2?

Thanks,
Jim
You should look at KaleCoAuto...

Re: Sealant on a Fuel Tank

Posted: Sun Nov 13, 2011 4:58 am
by Catigale
...used as a sealer on the turbine starters of C130s too.....

:D

Re: Sealant on a Fuel Tank

Posted: Sun Nov 13, 2011 8:58 am
by c130king
Catigale wrote:...used as a sealer on the turbine starters of C130s too.....

:D
Except at AutoZone a tube of this is about $5...

The USAF pays $5000 per tube for use on military aircraft...

Sort of like those $750 hammers or $1200 toilet seats...

Re: Sealant on a Fuel Tank

Posted: Sun Nov 13, 2011 11:44 am
by Hardcrab
c130,
Ask the next crew chief/plane captain you see for a "past date" tube of (Mil-C-something something)- 8802.

He'll know what it is, a fuel tank/general purpose sealant (brownish/dark olive greenish color) used all over the airframe.

Sadly, ( :D ) the stuff has a somewhat short shelf- life while in storage, so many unused tubes get thrown out for real A/C duty.

Re: Sealant on a Fuel Tank

Posted: Sun Nov 13, 2011 9:16 pm
by Divecoz
I did!! Thats a funny site! I will assume that sites owned by Cat??
K9Kampers wrote:
c130king wrote:Where can one get Permatex #2?

Thanks,
Jim
You should look at KaleCoAuto...

Re: Sealant on a Fuel Tank

Posted: Mon Nov 14, 2011 10:16 am
by mrbillfll
HI TEMP, RTV ? ITS BEEN OK ON MY PORTABLE TANKS.

Re: Sealant on a Fuel Tank

Posted: Wed Dec 21, 2011 11:13 am
by Tom Root
Hardcrab wrote:c130,
Ask the next crew chief/plane captain you see for a "past date" tube of (Mil-C-something something)- 8802.

He'll know what it is, a fuel tank/general purpose sealant (brownish/dark olive greenish color) used all over the airframe.

Sadly, ( :D ) the stuff has a somewhat short shelf- life while in storage, so many unused tubes get thrown out for real A/C duty.
That 8802 is great stuff! I'd wish there was a civilian counterpart as good as that stuff is! I was an Avionics Tech in the 'Corps, and we used it for Many things. I was on the A6-E Intruder, and OV-10 Bronco platforms. As you said though, it's shelf life was it's only poor point.