gasket sealers

well, that was interesting. still poking around for a sealer on an inspection cover on my fuel tank. i called permatex and asked about this. answer was ''no, we do not make a gasket sealer that is gasoline with 10% ethanol proof''. changes in epa laws etc. have taken the chemicals out of sealers that made them work 20 yrs ago.now products that were gas proof before[without ethanol] are not gas proof because of mandated chemical changes.
fwiw i haven't checked on the following but i was told these products will work. forgive the spelling....gasoila,e-sealer, ractoseal. something about gasoline pump installers using at least one of these products.

whats wrong with proseal?

bob burns
RV-4 N82RB

Regular proseal is a royal pain in the backside whenever a cover must be removed. If it were the 'right stuff' for removable panels, it begs the question: Why would the mfgr make a different product for removable panels?

Bob,

I wish we could get your Permatex guy and my Permatex guy in the same room.

This one (which I think you might have tried):
https://www.permatex.com/products/gasketing/gasket-sealants/permatex-permashield-fuel-resistant-gasket-dressing-flange-sealant/
says that it resists ethanol in the data sheet.

This product:
https://www.permatex.com/products/thread-compounds/thread-sealants/permatex-high-temperature-thread-sealant/
says that it works with 'gasoline', and I submit that Permatex is not marketing to aviators or that tiny fraction of the general population that has access to non-ethanol gas; they are marketing to automotive users running E-gas.

I haven't dug through data sheets on their other sealants, but I'd bet many of the others say effectively the same thing.

The folks I've talked with at Permatex have told me that E-gas is not a problem with the products (that I asked about) that are rated for gasoline.

Sounds like Permatex needs to get their story straight.

yep,
i don't know what to make of all this. ease of access plate removal is what keeps me from using proseal.

Proseal peels off very easily using a little heat from a heat gun and cleans up with paint stripper easily also.
A little heat with the heat gun and a putty knife seperated the fuel cap flange from the tank skin in seconds.
[/url]DSC02038 by David C, on Flickr[/IMG]
Proseal peeled off in big pieces when warmed up.
[/url]DSC02036 by David C, on Flickr[/IMG]
A couple minutes of dwell time with a quality paint stripper softened the remaining proseal and it started to lift.
[/url]DSC02040 by David C, on Flickr[/IMG]
A couple wipes with a rag wiped it clean. Then washed up thoroughly with water and clean rags. About 7 minutes total to remove the flange and get it all cleaned up.
DSC02042 by David C, on Flickr

Question for David C

Good to know how to remove proseal. Your last pic ( clean surface ) shows the flange hole very close to a seam seal on the tank rib. How is one to manage ?enough? heat to remove the flange but not compromize the adjacent seam seal ?

i guess in the whole scheme of things proseal wouldn't be such a big deal. i am going to pull the cover at least once before an annual and then every year after that. still have a few months before i seal up the fuel system.

bobnoffs said:

i guess in the whole scheme of things proseal wouldn't be such a big deal. i am going to pull the cover at least once before an annual and then every year after that. still have a few months before i seal up the fuel system.

Click to expand...

I am with you on the proseal, bob, but really did not want leaks. Not that you should not do it, but why do you want to inspect the inside of the tank so often?

My thought was to run each tank down to 1 gallon or so every year or so just to ensure the pickup was still tight, but a fuel pressure test with a clear section could be used to check for bubbles, like the pre-first-flight test.

EDIT: Hmmmm - that makes me think - if each tanks fuel gage was reading under 5 gallons, the test could pump from one tank to the other, and in the process check the fuel gage against the red cube. Repeat from side to side as needed.

Inspection Cover?

I'm a little confused as to what RV fuel tank has an inspection cover? The only time a fuel tank needs "opened" is when a fuel sender goes out or there is a leak. Likely with today's nifty phone borescopes, any part of the tank can be looked at through the filler opening.If you just have to do it, put a piece of spun fishing line in the sealant interface with a tail hanging out. When your ready to break the seal, pull it around the plate and it will cut the sealant. . I would use nothing but Proseal or its derivatives on a fuel tank, but then again my day job is maintaining the fleet of worlds largest flying gas station.

Larry DeCamp said:

Good to know how to remove proseal. Your last pic ( clean surface ) shows the flange hole very close to a seam seal on the tank rib. How is one to manage ?enough? heat to remove the flange but not compromize the adjacent seam seal ?

Click to expand...

It just needs to be warmed to soften up the proseal. This was a project where I was increasing the capacity of my fuel tanks and wanted to salvage the fuel filler flange. The whole end was eventually cut off which included the rib next to the flange. I was just experimenting with how well the stripper works cleaning the remaining proseal,,,and it works great. From the aviation isle at your local big box store.
[/url]DSC02039 by David C, on Flickr[/IMG]