What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Fuel tank (service bulletin)

AntiGravity

AntiGravity

Well Known Member
Just looking at this issue now. I had my tanks built for me by Evans Aviation and so far they have not had any fuel on them. I've removed the cover plate and the flop tube and will go about safety wiring as per Vans instructions. Will also proseal those suckers - they're never coming off again; if the safety wire and the proseal fails, then I'll just buy new tubes!!

Question though: should I re-use the cork gasket as is? It's in good nick and wasn't prosealed already (though the screws were). Or should I also use proseal (both sides of the gasket, or just one side and which one?). Or ditch the gasket and use proseal only? I'm thinking if I go gasket only I can always remove and add proseal later...

Thanks,
 
I've done probably 20 tanks. I always use proseal only. Never had a leak and the plates are not that difficult to remove.
Mel...DAR
 
Proseal only

Thanks Mel, I'll give that a go. Though I don't ever expect to have to get into the tank again I don't want to rule out the possibility.

I think I've seen in another post (which I've been unable to find) someone using hex head or socket head screws in place of the AN515-8R8 screws that are called out. Something to do with being esier remove on the plane if ever needed. Have you had an access issues or difficulties removing the screws on built RVs that you have worked on?

Finally, I'm also thinking of prosealing around all the fittings, as well as the safety wire. Similar to that shown by "Captain John" in the original service bulletin thread (which I've tried to upload again, but get an error). See any problem with this? A new flop tube is only $35 so in the unlike event of a future issue I'd just get a new one, but I figure with safety wire (covers the SB, satisfies insurance gods), and proseal it'll never come undone! :D I'll have the proseal mixed anyway, so why not?
 
AntiGravity said:
Finally, I'm also thinking of prosealing around all the fittings
--------
I'll have the proseal mixed anyway, so why not?
Click to expand...

There might be a possibility of the "wet" pro-seal dropping on the next rib, fuel pickup tube, etc. if it's all put together at once, and the position of the tank while it sets up.

I'm saying that, because when I pulled my covers off for the SB, I had pro-seal drippings from the screws that dripped onto the next rib.

In my case, it wouldn't have hurt anything, but the pros-seal did drip dropplets from every screw.

Originally, I had pro-sealed all the fittings too. They would never have come apart IMO, but were sealed several years before permanent mounting to the tanks. This time, I just safety wired & left them raw, after seeing the wet dripping possibility; as I wanted to do this operation all at once.

The first installation, I dipped the screws in Pro-seal. This time, I screwed them in a few turns and Pro-sealed around them.

As for gaskets, I used pro-seal only for the covers & fuel senders ------ both times. Also used the stock phillips screws, and purchased new ones for the second time around. They were easy to remove with a slow turning battery operated drill.
 
Screws

I was thinking of buying new screws as well, which is why I wondered about the hex or socket heads.

Since my tanks are off the wing I can proseal the flop tube fittings and leave it to dry for a few days before re-installing. No drips. The fitting at the bulkhead will need doing again of course, and I haven't yet worked out how I'm gonna get all the old proseal out of there!!
 
I forgot to mention that I use SS socket head (either hex or torx) screws everywhere possible. Have I ever mentioned that I HATE phillips head screws?
Mel...DAR
 
L.Adamson said:
There might be....

.... They were easy to remove with a slow turning battery operated drill.
Click to expand...

Battery powered drills motors make sparks. Not good near a used fuel tank.

Mark Scoggins
Flying -6
 
Dissimilar metals

No issues with dissimilar metal corrosion and all that (not that I know anything about it, but I have heard it mentioned before). I also like the idea of SS fasteners. And I too hate philips heads; once they're knackered, you're screwed... :(
 
markscogg said:
Battery powered drills motors make sparks. Not good near a used fuel tank.

Mark Scoggins
Flying -6
Click to expand...

In my case, it was totally fuel less. Not even fumes.

Of course, now I'm wondering about that big generator that I have, with an eight gallon fuel tank sitting right above it??????
 
AntiGravity said:
And I too hate philips heads; once they're knackered, you're screwed... :(
Click to expand...

If it's a round head, then cut a slot with a dremel or die cutter, a steady hand, and protection around the screw. One of my tank screws, did in fact strip.

For a flush screw, I suppose an EZ-out might work.
 
AntiGravity said:
No issues with dissimilar metal corrosion and all that (not that I know anything about it, but I have heard it mentioned before). I also like the idea of SS fasteners. And I too hate philips heads; once they're knackered, you're screwed... :(
Click to expand...
I know it's been said before, but Stainless isn't a strong as carbon steel for fasteners.
 
How exactly do we safety tie this

I have looked at the pictures and even written Van's. I am confused about where exactly in that nut I drill the hole and where the wire goes. Is this spelled out somewhere?

Regards,

Michael Wynn
RV 8 wings (tanks)
 
Question

AntiGravity said:
No issues with dissimilar metal corrosion and all that?
Click to expand...
This bit was supposed to be a question!

L.Adamson said:
If it's a round head, then cut a slot with a dremel or die cutter, a steady hand, and protection around the screw.
Click to expand...
Yep. But its not something I like doing [obviously!]. Of course, its possible to round hex socket heads too, especially when using cheap and/or ill-fitting hex wrenches.
 
L.Adamson said:
If it's a round head, then cut a slot with a dremel or die cutter, a steady hand, and protection around the screw. One of my tank screws, did in fact strip.

For a flush screw, I suppose an EZ-out might work.
Click to expand...


....or, (for round head) clamp on a small set of vise grips and break the bugger loose. The guy that invented this tool (and the inventor of the wonder bra) should both be eternally blessed. :D

Brian Denk
RV8 N94BD
 
mlwynn said:
I have looked at the pictures and even written Van's. I am confused about where exactly in that nut I drill the hole and where the wire goes. Is this spelled out somewhere?
Click to expand...
Me too. I have yet to find any good close-up pictures of how this is supposed to be done.
 
Left tank done - pictures on my kitlog site

Just to update this post: got my safety wire drill jig from Avery today and tackled this job. I'm relatively happy considering it is the first attempt I've ever had with safety wiring anything. For those that were asking earlier I have posted some pictures on my kitlog site. I'd upload them here but my computer steadfastly refuses to do so, no matter what I try. It wasn't nearly so bad as I thought, and having done it I have changed my mind about prosealing the whole thing; doesn't seem necessary. I'm not refitting the tube to the tank until tomorrow night, so if you have a compelling argument as to why I should proseal the fittings as well, then you have around 21 hours or so to convince me!! :D
 
Pictures!

Finally bothered to read Doug's instructions and use ImageShack !!

wings1110wa.jpg


wings1124gz.jpg


wings1132ez.jpg

http://img56.imageshack.us/img56/6986/wings1124gz.j
 
Fuel Tank (SB)

On the safetywire issue, glad a couple guys jumped in there before me.
I look at this stuff on a daily basis for a major aircraft manufacturer and that's not an acceptable method.

Also, in my opinion, the best method would be to drill a hole in the anti-rotation bracket installed on a previous SB and safetywire it in a good, positive tightening direction.

Van's SB drawing shows you coming off the nut, over the edge of the bracket, and then looping the wire around the upper fitting. If vibration in the tank is truly an issue, I wouldn't want my safetywire to chafe on a hard point edge of the bracket. Somewhere down the way it could cut it.
 
I have safety wired to the anti-rotation bracket on all the ones I've done to date. BTW, all the ones I've done have been "older" non-QBs that have been flying for 10 years or more, and I haven't found a loose one yet.
Mel...DAR
 
Wiring method

william weesner said:
remove the safety and start at the nut and twist and wrap around from the current veiw in a clockwise manner and tie off to provide a tightening motion to the nut..or move to the left one or two flats on the nut ( as nice as that drill job looks it should be a snap with the jig) (the wire may end up wanting to jump over the elbow if you just go around).
Click to expand...
Thanks, I have re-done this by re-drilling at the back side of the nut. But as you say, to me I'm now concerned that the wire could ride around the elbow. Being a flop tube, there is no antirotation bracket in there, since one is not called for in the plans. I think I may need to take the wire right around the fitting. If that doesn't provide a 'fit' that I'm happy about I'll proseal that sucker.

After all, as several threads and about a million posts have already mentioned: this method of safety-ing probably has more to do with Vans liability than an actual issue; over 4500 flying RVs and none had this mod before the SB. I figure if I wire then I satisfy the insurance gods, and if I then proseal as well I can satisfy the safety gods; not bad to be able to satisfy two gods in one day! :D
 
add to the count

Two RV's with pickup tubes that were over 15 years old and as tight as the day they were installed!

Seems that we have a count of this going on the forum?

Doyce Graham
 
You must log in or register to reply here.
Back
Top