To replace or repair......
Mike, just thought I would chime in here after looking at your spar last night, and thinking about how this may have happened. First, I am not certain if all of the rivets that were smilied were the ones that were attaching the hinge brackets or not. But I suspect that this is what happened:
As you described to me, you started setting the rivets that attach the spar doubler and the angle brackets to the spar web. I think that you may have forgotten to adjust your squeezer to allow for the additional thickness of the hinge brackets, and this is why the smileys occured. Apparently the force applied was enough to bend the adjustable set holder on your squeezer. Then the other smileys occured because the set holder was bent. Maybe that's not how it occurred, but that's my guess. A hard lesson to learn for sure, but one that many others have also experienced to one degree or another.
After reviewing the wisdom of those that replied before me, and thinking a bit more about this last night, here is my suggestion as to how to proceed:
1. Send pics to Vans with email asking them if a doubler should or could be used here. They are the kit manufacturer and should be consulted for questions about structural issues.
2. Review AC43.13 to determine of there is any guidance as to applying a patch or doubler for a condition such as this.
3. Order a new adjustable set holder for your squeezer. It is definitely bent.
4. If it were me in your shoes, I would assess this as follows:
- Is the damaged part structural - yes
- Does the damaged area involve a hinge attach point - Yes
- Are some of the smilies deep - yes
- Would you sleep well at night knowing that the damage is there, even if the smilies are dressed out and an appropriate doubler is applied? (You'll have to answer that one yourself)
- can the same spar angle support brackets and the spar doubler be re-used if the spar is replaced - yes, assuming the integrity of the holes is retained.
Personally I am siding more with the recommedation to drill out all the rivets and replace the spar, unless Van's and AC43.13 provide recommendations for applying a doubler or other fix for this situation. That said, drilling out AN470-4 rivets is not the most fun thing to do. Using the removal tool that you recently purchased makes removing the manufactured head relatively easy, but poundng out the rivet shank can still be a challenge sometimes.
The best thing to do before beginning this on the actual airplane parts is to set up some practice pieces with about the same thickness as the actual parts, drill some holes, set some rivets, and then practice removing them. As others have stated, this will not be the last time you will have to deal with removing rivets, so the more you practice, the better you will get at it.
Lastly, when you finally get back to setting rivets again, using the duct tape trick mentioned earlier, or even masking tape, will definitely help prevent smilies in the future. Remember to always adjust your set holder to allow for changes in material depth. That built up RV-10 VS rear spar has a lot of different layers to it, so you just have to be mindful about all the material depth changes and adjust your set holder acoordingly.
If you need help removing rivets, just give me a call.
Bryan
I was working on riveting the vertical stabilizer spar when I ran into a little problem with my pneumatic squeezer. Apparently the adjustable set holder in my squeezer was slightly bent, which meant that when the dies came together, I made some pretty deep smiles in the spar skin.
https://picasaweb.google.com/109414440645033591020/August42011#
Now these rivets go through the spar skin, the doubler behind the skin, and finally the brackets that will eventually hold the rudder to the spar. The smiles are deep but did not penetrate through the skin. My concern is that such a stressed area around the rivet might weaken the area around the rivet enough that I could have cracks in the skin, and eventually structural problems with the vertical stabilizer spar. Then again, the rivets are going through a good deal of material. I intend to see what the folks at Vans think about my predicament, but I figured I ask the forum too. What do you "experts" think. Should I suck it up and start on a new spar, or keep plugging (once I've replaced my adjustable set holder)??
