HS Flange Crack

Only 8 rivets kept the HS from being officially complete.The plans have you wait to rivet the final inboard ribs until you can take the HS out of the cradles and lay them down for better access to rivet. Even with the HS flat on the table the rivets are somewhat awkward to get to. The first rivet I drove was unacceptable and had to be drilled out. After regrouping and retooling with my offset rivet set I started to drive the new rivet. I stopped after getting the rivet partially set to check the progress. The pictures below show what I saw. The point of the bucking bar I was using must have cut right through the adjacent flange while I was riveting. Can the inboard rib be removed and replaced without drilling out the entire side of the HS? My concern is that the the way the rib is nested in the stringer assembly may prevent me from drilling out the affected rib.

Certainly no expert, but I would cut that flange off and smooth the edges in place and rivet an angle to the rib duplicating that flange.

Ron and I think alike. That's what I'd do too.
Tim

Interesting thoughts guys, that's what makes VAF invaluable. Those single hole flanges are so pesky!!

Something to consider:

-spar/web rivets 'appear' to be overdriven, a lot.
-rivet above the rivet/flange you are questioning 'appears' to be under driven and the flange doesn't look like it's fully nested. Address.
-2 rivets up - 'appears' to be set in an oversized or oblong hole. Address.
-flange dimples 'appear' to be less than crisp, a lot.
-if you keep your bucking bar on the rivet you won't scratch the primer off of your parts

Above comments realizing that pics can be deceiving.

Response to your question: many-a-flange has been removed and replaced with a new one.

As experience is gained skill usually improves. Rivet gauges can help in the meantime.

Good luck and have fun. Slow and steady as she goes .

Cracked flange

I had similar difficulties with these rivets. A second set of hands, an offset rivet set, and a piece of rubber tubing around the rivet tails got everything comes cinched up tight. I also put a piece of masking or duct tape around the bucking bar to keep scuffs to a minimum. A helper, in my opinion, is required to get these particular rivets set properly. Best of luck.

duct tape

Also, you can put small pieces of duct tape your bucking bar to be placed next to primed aluminum...this will prevent the aluminum/primer from being scratched.

Radiusing the bucking bar edges and some duct tape will also protect the primer/parts. I had to dress my tungsten bars as the edges were way to sharp. If you need that last 1/16" of the edge of the bar, there is probably something else wrong.

That bar looks more like a cut off tool than a bucking bar.

Not a -14 guy but a couple observations.
Definitely use a different bucking bar.
Photos are deceiving but check your rivets on the spar. They look a little over driven.
This comes from a guys who has had his share of "redo's". Good luck

***Update*** The factory's recommendation was to cut the tab off and fab a piece of angle and attach it to the web and the spar. Had I not already attached the forward spar replacing the rib may have been an option.

Thanks for all of the help guys. And yes, pictures are very deceiving.

over/under driven rivets

Noting the above comments on over-driven rivets, I came across some interesting testing performed by a fellow RV-er:

http://www.eaa124.org/Contributions/body_contributions.html

Jake14 said:

Noting the above comments on over-driven rivets, I came across some interesting testing performed by a fellow RV-er:

http://www.eaa124.org/Contributions/body_contributions.html

Click to expand...

That is very interesting. I would like to see that test re-done with lines of rivets, say four or five rivets long, with only one rivet driven out of spec. The 737 that had to make an emergency landing in Arizona after a top skin failed was found to have some poor rivets 8n a lap joint. The report, IIRC, noted that some rivets had snowman holes and possibly other defects. Failure of a single or small number of rivets caused a progressive load transfer to other rivets, which failed in shear in a chain reaction resulting in loss of the skin.

It would be very interesting to see similar tests done on a group of rivets, the bulk of which were correctly driven, with one out of spec, to see just how much that one rivet changes the joint strength.