Tank access cover plate

Ok, I'm missing something really basic here and I need some guidance. Both the fuel sender unit and the access plate are attached to the inboard ribs of the fuel tanks with #8 screws and gaskets.

But what stops fuel from leaking along the fasteners? Do I have to wet install the screws and slather proseal all over the outside of the screws?

Some websites show no sealant on the fasteners at all. Am I missing something?

My instructions for the -9 indicate that proseal should be put on screws before being inserted. Likewise, it provides the option of prosealing the entire cover plate and gasket on, making the gasket sacrificial if you ever need to remove the cover plate. In retrospect, I used too much proseal on my first tank--around the entire perimeter of the sender and cover plate and on top of each screw (though I left the screw slots accessible to a screwdriver), but it doesn't leak. My second tank will have much less proseal here and will look much neater--I hope!

I say goop up the screw threads. It might be a good idea to use socket head screws though in case you ever need to get em out.

Steve Zicree

The fuel sender can be prosealed in, and the inside of the nutplates gooped up with proseal. However for the covers, I'd just goop up the screws with Fuel Lube prior to screwing them in. I did this and they haven't leaked a drop. I would not proseal the access plates on in case you should ever need to get inside. The rubberized cork gaskets, gooped up with Aviation form-a-gasket have worked just fine and not leaked a drop either.

Someone mentioned using socket head screws. I recommend Torx screws, for this and every other application on the plane.

Jeff Point
RV-6
Milwaukee

I am doing Caps so I could be talking out my breezeway (like I usually do), but I have seen some people use those (I forget the real name but) "Sealing" plate nuts. Do you know what I mean? They have an acorn shaped body that, when installed forms a seal between the interior and exterior environments.

Perhaps those could be of use here?

CJ

Thanks

Funny thing, it turns out my -9 instructions have the same information as alpinelakespilot2000. Thanks for all the tips. It certainly seems possible to strip out the phillips screws, so I will run to the local Spencer Aircraft and pick up some replacement hardware and lube.

BJohnson said:

Funny thing, it turns out my -9 instructions have the same information as alpinelakespilot2000. Thanks for all the tips. It certainly seems possible to strip out the phillips screws, so I will run to the local Spencer Aircraft and pick up some replacement hardware and lube.

Click to expand...

Brice--I wouldn't worry about it now--just stick with the round head #8's unless you have money to burn. I had no problem using the #8 screws and they had no tendency to strip the heads (so long as you're using the right size screw driver). They don't have to be screwed that tight plus the proseal will lube the threads making them pretty easy to go in. If for some reason you ever need to take the plate off, just use new fasteners next time. All in all, though, there is really little (if any) reason that you'd ever need to take them out, short of a leak. Also, to help avoid any stripping, work the screws in a few turns at a time rather than tightening them up completely one at a time.

Good luck.
Steve

Sealing tank access cover plate

Here's how I did it. No gasket, just proseal. Wet screws. No leaks, so far (knock on an EAA chapter 1000 standardized work table)

http://www.rv8.ch/article.php?story=2004082222240152

Go to Wicks site at the following URL: http://www.wicksaircraft.com/catalog/product_cat.php/subid=2381/index.html
and look at the cap nuts they have. These are NAS1473A08 nut plates that are capped and have an O ring seal against the back side of the plate. They are pricey at $2.05 each for the 8-32 threads, but they will not leak! Shopping around may net you a cheaper price, but I recommend them.
Good luck.