Another figure 8 Dimple Story

Greetings fellow RV8rs. I created a dimple problem that seems to be a bit different from other posts that I searched on. Same story though: skin slipped off male dimple die and I pounded the ram and made a new hole right next to the intended one. My goof is along one of the Stiffeners of the top right elevator skin, whereas most folks seem to be doing this along the spar rivet line.

I used my flush set on the rivet gun and a back rivet steel plate to" level out" the new hole - always works nicely. Then I decided to re-dimple the intended hole. The pics below show the result. Obvious crack along the edge of the dimple.

So I ask those of you that are wiser than I, how should I fix this?

1. Apply an oops rivet after drilling out? (Please specify the drill size and oops rivet size I should use).
2. Flatten this dimple with my flush set and drill and dimple 2 new holes on either side of the bad one? (Concern I have here is leaving the crack alone without dressing it out somehow, and that it may continue to grow even after it is filled.)
3. Time for a new skin ?

Thanks.

I'd suggest two options... One, stop-drill the crack, and rivet the now-dimpled hole as-is. Two, stop-drill the crack, flatten the dimple again, and make a new hole and dimple a safe distance from the old one (or one on either side). Then plan on filling the old empty hole before paint.

I second what Rob said. Stop drill, flatten the stuff out and drill a new hole at a reasonable distance. However, if this is the rivet on the stiffener at the leading edge of the rudder, I would consider two rivets (one on either side of the bad one). Those rivets (leading edge of the rudder at the stiffeners) sometimes tend to cause cracks anyway unless prosealed onto the skin.

cheers and build on,
greg

Third option

Assemble with proseal and an "A" rivet. I don't think one non structural rivet in a line is going to create any more problems than a AD rivet that will expand in the hole with enough force to possibly propagate the crack. I can mail you a few if you want.

Thanks for the responses

Thank you all for chiming in. I guess I have to kind of laugh a little regarding the recommendation to stop drill the crack. This means that I basically have to drill out the void left by the bad hole that I already pounded into submission in order to try to fill it back up. Oh well, if you can't laugh at your mistakes, you will have a hard time finishing the project, right?

Andrew, I am wondering what you meant by an "A" rivet. A proseal order is definitely on the horizon, so I am interested in your proposal as well.

Greg - This is unfortunately on the top side of the right elevator skin, and not the rudder. So I will have to endure the slightly imperfect appearance due to the repair, which is not a big deal for me, since it will be filled and painted eventually.

Rob, I'll take those options over spending the money on a new skin. Thanks for providing some different options.

Andrew means you should use an AN426A 3-? as opposed to an AN426AD 3-? rivet. However, I don't think there will be that much difference. In either case you should check after setting the rivet to be sure expansion has not extended the crack. If it has not, there should be no further worries.

An "A" rivet

is pure aluminum, and very soft.

"A" rivets explained

Thanks Patrick and Andrew for clarifying.

A post mortum - applied a fix and moving on

Thought I would post some pics of the solution I implemented, which was to flatten the existing dimples in the skin and stiffener of the affected area, stop drilled the crack in the initially flattened area where the dimple die slammed a new unwanted hole in my elevator skin, and drilled and dimpled two new holes in the skin and affected stiffener, one on each side of the botched area.

If there was any doubt about this being a figure 8 in my initial pics on this post, there is certainly no doubt about it now. I am OK with the less than desireable cosmetic impact, since I care more about it being in flying condition than if the rivet line is totally symmetrical. My blog has a few more details of the process I used to apply the fix, so you can visit my post there for more info if you wish. Filler will definitely be a big part of my future I guess, and it will definitely need to be applied to cover both holes of the figure 8.



And a close up of the figure 8 that was necessary in order to stop drill the cracked area. These two holes will be filled. The new dimpled holes are also in this pic. Not sure about the cleco at the bottom, but I think that is an optical illusion due to the camera being tilted to avoid light reflections (The cleco is not really right next to the new dimpled hole on the bottom of the pic):

Bryan,

You could always put a similar extra rivet on the other side and then only RV builders would notice.

I'm not sure that it will be necessary to fill anything from the looks of your photo.

cheers,
greg