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Best way to fix VS "outies" caused by ribs

UnPossible

Well Known Member
Well, I guess I can add my name to the list of folks that have been bitten by the forward ribs in the RV-10 VS being a little long resulting in a couple of minor "outies" in the VS skin.

Unfortunately I found out about the issue, after I had struggled a bit to cleco on the VS skin. I have trimmed ~1/8" or so off the nose of the ribs, which should make fitting the skin back on the frame much easier.

Anyway, looking for ideas as how to best take care of this.... the "outies" aren't bad enough to justify spending $100+ on a new skin. I was planning on trying to tap them out with a dead blow hammer. I figured worse case, I'll tap them into "innies" and just fill them with epoxy/microballoons at some point later in the build. Any better options?

Thanks,
Jason
 
This issue comes up a lot on all types.

The problem is not that the ribs are too long. On the sharp radius at the front of the rib, the small flange tabs bent over result in a square instead of a curved profile. This means that the corners sit proud of the theoretical shape. The way to prevent the outies is take these corners off. This results is the tab crease being shorter than the width of the tab - a sort of scallop shape. Clearly, you have to be careful not to remove too much material. It also helps if you then bend down slightly the edges of the tabs to give them a curved shape.

As to what to do if you end up with outies, I agree with your plan - knock them in slightly and then fill the small depression.
 
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I had the same issue, and used a rounded bucking bar to compress the deformed metal back into shape by hand. Use a rounded corner of a bar locally if you need more force to compress the metal. You could barely tell there was an issue, even when you knew where to look. The paint covered the remaining blemish.

A hammer may be more force than you need. You may end up stretching the surrounding metal if you hit it too hard.

Aaron
 
Be careful using a dead-blow or soft-faced hammer. These hammers tend to depress the unsupported skin area adjacent to the sharp-pointed outie thus accentuating the boo-boo. I used a smooth-faced bucking bar on the point of the outie to carefully encourage a flattening effect. However, this action likely creates a hardened stress riser point in the skin. My next plane will be PERFECT!! ;)
 
Now that you are aware of this, file the nose of the ribs in future where the sharp change in radius occurs to remove the "peak". I`m sure it`s in the manual somewhere.
To repair what you have now - I used my rivet gun with the flat snap in it and turned the gun right down using the regulator I have screwed into the back of the gun.
Start soft on the gun as always and dial it up one click at a time until you get it right. Mark the dead centre of the outie with a sharpie. Put some packing tape on the snap and place the snap right on the peak of the outie and the impact will dress down the peak on the rib under the skin and all will be good. I`m not talking about belting the **** out of anything, just gently dressing the "outie". It takes a lot less force than driving the 3.32 rivets and won`t damage the structure. If done right, you can rest a straight edge on it, and the packing tape on the snap will mean you have no marring on the skin at all.
Once the gun is set up, the second and subsequent outies will dress out with 1 very short burst of the gun. Just a couple of gentle and precisely targeted taps (dead on the peak), that`s all.

If you`re like me, the hardest part is getting over the fear of doing it the first time. After that, you wonder what all the stress was about.
 
This issue comes up a lot on all types.

The problem is not that the ribs are too long. On the sharp radius at the front of the rib, the small flange tabs bent over result in a square instead of a curved profile. This means that the corners sit proud of the theoretical shape. The way to prevent the outies is take these corners off. This results is the tab crease being shorter than the width of the tab - a sort of scallop shape. Clearly, you have to be careful not to remove too much material. It also helps if you then bend down slightly the edges of the tabs to give them a curved shape.

As to what to do if you end up with outies, I agree with your plan - knock them in slightly and then fill the small depression.

Paul is exactly right. More info in Section 5.2 of the Recently Updated Section 5 of the construction manual.

As Paul said, the only way to really fix an outy is to turn it into an inny though yuou can sometimes make it go back flat if it is not ver bad. As already mentioned don't use a hammer to do this. Choose a tool and use hand pressure. I often use corners or edges of bucking bars. Sometimes even the round end of a small ball peen hammer by pushing it against a dent at a single point.
 
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