Noah
Well Known Member
Greetings-
Last month I purchased an RV-7A project from another builder. The fuselage is substantially complete, with top skins to be riveted on and some cabin work. I recently discovered that the fuse side skins, which are completely riveted except at the firewall and the forward top skin, were dimpled but the longeron underneath wasn't countersunk at the intersection of the side skin and fwd top skin. There is no way to get a countersink tool under the skin at this point. (See Photo) The fwd top skin is not yet dimpled.
Because the top skin will cover the top line of rivet holes in question, the dimpled side skins will be hidden. One builder friend recommended not dimpling the longeron, flattening the existing dimples in the side skin, then countersinking the side skin, then dimpling the top skin and riveting. This has the advantage of being quick and easy, but I am concerned about how flat the already dimpled side skin can be made, and the additional cold working of the dimpled, then flattened area, and the potential for cracks.
Another builder recommended removing enough rivets from the side skin around the area in question so that the side skin can be peeled back, allowing the longerons underneath to be countersunk. This will require a lot of rivets to be removed to get a drill and countersink in there, which will take a lot of time and increase the potential for additional damage. There are seven holes (fourteen both sides) which are supposed to take 1/8 rivets, but the existing holes in the side skin and longeron are oversized by .018-.025.
I suppose that either of these repairs will require the use of "oops" rivets due to the oversize holes in the skin and longeron.
Any recommendations? So far, I've (almost) completed Van's toolbox kit so this will be a steep learning curve!
Highest Regards,
Noah Forden
Rhode Island
RV-7A Finishing
Last month I purchased an RV-7A project from another builder. The fuselage is substantially complete, with top skins to be riveted on and some cabin work. I recently discovered that the fuse side skins, which are completely riveted except at the firewall and the forward top skin, were dimpled but the longeron underneath wasn't countersunk at the intersection of the side skin and fwd top skin. There is no way to get a countersink tool under the skin at this point. (See Photo) The fwd top skin is not yet dimpled.
Because the top skin will cover the top line of rivet holes in question, the dimpled side skins will be hidden. One builder friend recommended not dimpling the longeron, flattening the existing dimples in the side skin, then countersinking the side skin, then dimpling the top skin and riveting. This has the advantage of being quick and easy, but I am concerned about how flat the already dimpled side skin can be made, and the additional cold working of the dimpled, then flattened area, and the potential for cracks.
Another builder recommended removing enough rivets from the side skin around the area in question so that the side skin can be peeled back, allowing the longerons underneath to be countersunk. This will require a lot of rivets to be removed to get a drill and countersink in there, which will take a lot of time and increase the potential for additional damage. There are seven holes (fourteen both sides) which are supposed to take 1/8 rivets, but the existing holes in the side skin and longeron are oversized by .018-.025.
I suppose that either of these repairs will require the use of "oops" rivets due to the oversize holes in the skin and longeron.
Any recommendations? So far, I've (almost) completed Van's toolbox kit so this will be a steep learning curve!
Highest Regards,
Noah Forden
Rhode Island
RV-7A Finishing