Center Section Oops

Now that I have the fuselage section started, I figured I'd get my first mistake out of the way. I'm wondering, however, how much of a mistake I made. This is from riveting the F-704L to the F704B center section. After completing the majority of the rivets, I missed the back of one rivet with the Bucking Bar but diligently hit the rivet head. Now it is inwardly deformed on one side and a gouge on the other. Question is, do I need to replace both components, construct a place to go over it or what? Given that it is the center section where all the stres and loading action is, I need to be sure. Thoughts?

I think I would be talking to VANS! Send them the pic you just posted.

That was my next step. I'll give them a ringy-dingy tomorrow morning.

Ouch, I am doing that step this weekend, thanks for sharing, I feel your pain. I think I would be concerned also, but I think the majority of the load is on the upper and Lower bars in compression and draw?

Rivet Technique

I don't mean to be "that guy", but from the photos it appears that the majority of those rivets are over-driven. Of course it could be the photo.

Do you have a shop head gauge?

bret said:

Ouch, I am doing that step this weekend, thanks for sharing, I feel your pain. I think I would be concerned also, but I think the majority of the load is on the upper and Lower bars in compression and draw?

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You are correct Bret, the Spar Caps carry the bulk of the load. However, the Spar Web, the part damaged, is an integral part. Together, the Caps and Web form the Spar. In the certified world, anytime it comes to a Spar repair, the only authority is the aircraft designer, a repair manual from the manufacturer that documents acceptable repairs to the Spar, or you have to have a certified Airframe Engineer do an analysis and engineer a repair.
I know we are not in that world, but when it comes to airframe repairs, I follow it.

Most other components, ribs, bulkheads, sheet, etc.... can all be repaired per AC43-13-1b or per an airframe repair manual.

Spoke to Vans. From looking at the pics I sent to them, they do not feel that it is a concern structurally, more of a cosmetic issue. They noted the conduit access near the hole in reference to stress and loading in the area. They indicated that a cover plate could be placed over it but removing the surrounding rivets to do so may be more harm than good. Of course, I do need to replace two rivets on that side that are, in fact, over-driven as noted by Kurt W as well as one misshapen. They went on to say that it would suffice to prime the area involved, perhaps flatten the area, re-rivet the hole and move on.

GKnut said:

Spoke to Vans. From looking at the pics I sent to them, they do not feel that it is a concern structurally, more of a cosmetic issue. They noted the conduit access near the hole in reference to stress and loading in the area. They indicated that a cover plate could be placed over it but removing the surrounding rivets to do so may be more harm than good. Of course, I do need to replace two rivets on that side that are, in fact, over-driven as noted by Kurt W as well as one misshapen. They went on to say that it would suffice to prime the area involved, perhaps flatten the area, re-rivet the hole and move on.

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Good news Glen. I wouldn't rush to remove those rivets. The mil spec for shop head tolerance is far more forgiving than most people think. I do not have the reference handy here at work but hopefully someone can post it. Get your mic. out and start measuring. If they meet the mil spec, move on, event the mishapen one is not a problem. You are allowed a few bad rivets here and there and removing rivets can cause more harm than good as noted.

JonJay said:

Good news Glen. I wouldn't rush to remove those rivets. The mil spec for shop head tolerance is far more forgiving than most people think. I do not have the reference handy here at work but hopefully someone can post it. Get your mic. out and start measuring. If they meet the mil spec, move on, event the mishapen one is not a problem. You are allowed a few bad rivets here and there and removing rivets can cause more harm than good as noted.

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Found it
http://www.vansaircraft.com/public/Specs.htm

It's good to know there is alot of competent voices out there to provide good advice and references. Thanks.