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Looking for tips on tank/leading edge rib prep.

Sieldan

Member
Greetings all,

In my -8 build, I have reached the point of working the leading edges and the tanks. The leading edges are done to the cleco point and its time to get to work on the tanks. My issue is this: I dont know what Im doing to get the ribs to seat nicely in their positions. The leading edges took a bit of finagling to cleco in. I just know that if I have to do that with the tanks, Im going to get leaks. So, what are your tips, suggestions, rules of thumb, whatevers on how to get the tank ribs to lay flat with out oil canning, and thus, I hope, seat into the skins easily?

Thanks yall.
 
Skin and ribs

Greetings all,

In my -8 build, I have reached the point of working the leading edges and the tanks. The leading edges are done to the cleco point and its time to get to work on the tanks. My issue is this: I dont know what Im doing to get the ribs to seat nicely in their positions. The leading edges took a bit of finagling to cleco in. I just know that if I have to do that with the tanks, Im going to get leaks. So, what are your tips, suggestions, rules of thumb, whatevers on how to get the tank ribs to lay flat with out oil canning, and thus, I hope, seat into the skins easily?

Thanks yall.

First fit is always tough. After a few in and outs, they seem to cooperate.
 
The trick is to flute the ribs, straighten the flanges, then flute again until they are perfectly straight. A touch on the Scotch Brite wheel on the rib tips flanges (on the inside where the flat flanges mate with the curved skin) helps as well.

Carl
 
The trick is to flute the ribs, straighten the flanges, then flute again until they are perfectly straight. A touch on the Scotch Brite wheel on the rib tips flanges (on the inside where the flat flanges mate with the curved skin) helps as well.

Carl

Thanks Carl.
 
I'm building extended tanks for a RV4. Nothing is pre drilled on my 4 kit. This technique noted below works to stabilize ribs while working.

I used 2inch pvc cut square and exact length between ribs. I ran a 3/16 threaded rod through PVC and rib tooling holes with nuts on each side of ribbs to stabilize leading edge of nose ribs. One end of each PVC pipe had a small notch for bead roll to allow PVC to sit flat on ribs.
 

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Yes, on the tiny leading edge tabs (the ones without rivet holes), you can file or use the scotchbrite wheel to round them down so that they fit inside the skin much nicer.
 
One end of each PVC pipe had a small notch for bead roll to allow PVC to sit flat on ribs.

Hi, I am also building old non_prepunched RV4, looks like a great tip. I did not understand the description of putting a notch for the "bead roll", could you clarify?

Thanks
 
Hi, I am also building old non_prepunched RV4, looks like a great tip. I did not understand the description of putting a notch for the "bead roll", could you clarify?

Thanks

I think he’s talking about the bead on the ribs for strength.. he notched the PVC tubing to clear that possibility?
 
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