Tank Sealing

[s24789]

I am about to install the fuel sending units in my 7A wings. Looking for thoughts about scrapping rubber seal and sealing with ProSeal. Also wondering if there is any need to replace the cork seal in the main cover before wings go on or just replacing with ProSeal?
Please any constructive ideas are welcome.

[instructor_bill]

I also did a bit of reading on the topic before sealing them up.


I decided to go with titeseal along with the gaskets supplied with the wing kit and sending units. If memory serves... it's what the Orndorff vids advocate.

I've found titeseal easy to work with as it never dries, held up fine to my pressure tests, and is easy to clean up. I also will never have to worry about being able to get back into the tanks should I need to remove the cover or sending unit. You will however need to use gaskets of some sort with this product.

I'm pretty sure I bought it from aircraft spruce.

[Mel]

Do not use the cork gasket. Regardless of other sealants you use, the cork gasket will become saturated and begin to seep within about 3-5 years.
I use pro-seal only with no gaskets. I've done many tanks and never experience leaks. Removal, if necessary, is relatively easy with a sharpened putty knife.

[L.Adamson]

Originally Posted by Mel

Do not use the cork gasket. Regardless of other sealants you use, the cork gasket will become saturated and begin to seep within about 3-5 years.
I use pro-seal only with no gaskets. I've done many tanks and never experience leaks. Removal, if necessary, is relatively easy with a sharpened putty knife.

And there are a whole lot of other RV builders who found this to be true.... too!

Besides, if you really have to get into the tank later, the proseal can be removed with a few simple tricks. But in the meantime, you'll have the best possible seal by leaving all the gaskets hanging on the garage wall pegboard.

L.Adamson --- RV6A

[jsharkey]

Originally Posted by L.Adamson

And there are a whole lot of other RV builders who found this to be true.... too!

Besides, if you really have to get into the tank later, the proseal can be removed with a few simple tricks. But in the meantime, you'll have the best possible seal by leaving all the gaskets hanging on the garage wall pegboard.

L.Adamson --- RV6A

Proseal only - no leaks so far. A leak (slow drip) from a fuel drain with a minute piece of building debris caught on the O ring - even after what I thought was a thorough pre clean. Pain to drain the tank but easy to fix.


Jim Sharkey
RV-6 Phase 1

[Rick6a]

Originally Posted by Mel

Do not use the cork gasket. Regardless of other sealants you use, the cork gasket will become saturated and begin to seep within about 3-5 years.....

Originally Posted by L.Adamson

........you'll have the best possible seal by leaving all the gaskets hanging on the garage wall pegboard....

Using medium weight Tite Seal, I installed the cork gaskets on the fuel tanks of my -6A. As a newbie at the time, I simply followed a George Orndorf construction video suggestion. That was over 8 years ago....well past an arbitrary 3-5 year prediction of failure. Still, in all this time no seepage or leaks have been observed.

That said, since that time 8 years ago, I contacted Van's regarding this perennial issue. Turns out, they use cork and proseal. So the second time around, I followed their highly seasoned and experienced lead and chose to go with cork and proseal. With thousands of RV's flying and especially given all the feedback they get from builders past and present, if Van's discovered a fundamental problem using cork gaskets as supplied with their kits, don't you think they'd let us in on it?

When those Tite Sealed cork gasket and cover plates finally start to seep or leak....I'll let others know. At this point 8 years later, time and leak free operational experience have suggested to me there is no right way or wrong way, just differences in personal OPINION. Opinions are shaped by our own experience and to a lesser extent...what we "hear" from others. My opinion? Just do what you want.....but do it with care.

[Kyle Boatright]

My airplane had no leaks with the proseal and cork for 5-6 years until I had to pull the tank access plates to comply with the service bulletin on the anti-rotation fitting for the fuel strainer. Like the pictures in a previous post, I had applied a filet of proseal over the edges of the cork and had buttered the cork on both sides with proseal.

When I replaced the access plates, I skipped the cork gasket and just used proseal.

Either way works.

[Sam Buchanan]

Originally Posted by jsharkey

Proseal only - no leaks so far. A leak (slow drip) from a fuel drain with a minute piece of building debris caught on the O ring - even after what I thought was a thorough pre clean. Pain to drain the tank but easy to fix.


Jim Sharkey
RV-6 Phase 1

Why did you drain the tank? Next time this happens, take the 1/8" NPT plug that you carry in your flight bag (hint, hint) and quickly swap it out with the drain valve. You shouldn't lose more than a few dribbles of fuel. After cleaning the o-ring, you can reinstall the valve at your convenience without draining the tank.

Even better than carrying the plug, a spare drain valve will have you flying again in a few minutes if the o-ring lets go while on a ramp away from home (usually where it happens......).

[Kyle Boatright]

Originally Posted by Sam Buchanan

Why did you drain the tank? Next time this happens, take the 1/8" NPT plug that you carry in your flight bag (hint, hint) and quickly swap it out with the drain valve. You shouldn't lose more than a few dribbles of fuel. After cleaning the o-ring, you can reinstall the valve at your convenience without draining the tank.

Even better than carrying the plug, a spare drain valve will have you flying again in a few minutes if the o-ring lets go while on a ramp away from home (usually where it happens......).

I carry a spare quick drain for that purpose. And a 7/16" wrench (IIRC). Pull the old drain, thumb over the hole, position the new drain and screw it right in. Clean the junk out of the drain you removed, and put it back in the spares kit. Literally a 1 minute job if you have the stuff on-hand.

[rvbuilder2002]

Originally Posted by Rick6a

.

That said, since that time 8 years ago, I contacted Van's regarding this perennial issue. Turns out, they use cork and proseal.

You received incorrect information.
All of Vans Aircrafts protypes and demonstrators have covers and level senders installed with tank sealant only.