Hi all,I have heard of builders placing a small amount of fuel tank sealant in the elevators to prevent skin cracking. Where should it be placed,between the stiffeners?Thanks
Just a dab applied at the very trailing edge of the stiffeners, bonding the stiffeners to each other.
Its important that the stiffeners do no contact each other or they will create a stress "bulge" in the trailing edge skin. I'm replacing an RV4 elevator skin right now due to stress cracks from improperly trimmed stiffeners.
Where Walt said, however I believe this is more of a problem with the ailerons (and other control surfaces) that are folded at the trailing edge. The trailing edges on all the 9 control surfaces are seamed.
Just a dab applied at the very trailing edge of the stiffeners, bonding the stiffeners to each other.
Its important that the stiffeners do no contact each other or they will create a stress "bulge" in the trailing edge skin. I'm replacing an RV4 elevator skin right now due to stress cracks from improperly trimmed stiffeners.
I spoke to Vans on this very subject. The answer I received (from Ken Scott) was that the sealant WAS NOT NECESSARY in aircraft with a a "AEX wedge" (such as the RV-9A) at the trailing edge. Only aircraft with solid or folded trailing edges was this necessary. It is also in the builders manual stating this very fact. Don't add unnecessary weight at the trailing edge of control surfaces. If you don't believe me, call Vans.
