Bad rivet question

So I managed to do this...



and I am needing some advice on a good technique to get it out. I have no idea where the center is as I mushed it with the squeezer pretty good.

Additionally I had two ribs push out.


This one I already drilled out the rivet. You can see the flange is pushing away from the rear spar. I could use a good technique to sit these flat on the rear spar. If I get a clamp in I don't have enough room for a bucking bar or squeezer head. This is a countersunk rivet so it has to be put in this way.

Here is the other rib that got pushed out. I couldn't get access to squeeze or buck these so the shop head would be on the spar.


Thanks as always for the help

That's a nice Smiley...you'll have to drill easy, be sure not to go deep, till you can pop the head.
The other option is to drill the shop head. I've taught this, and it can be done. Again, don't go deep, just work it till you can pop the tail off.

As far as seating the flange, use a fiber washer around it, like a felt type washer, as you squeeze or buck. The hole should be about the size the shop head will be when finished or slightly larger.

As you squeeze/buck, it will push the material down.

Good luck..

One option is to use a Dremel and use a cut-off wheel to grind a flat on the manufactured head. Then it's pretty easy to find the center.
When doing this type of grinding I use 2 cut-off wheels together.

What Mel said. The cutoff wheel is great for these situations when you have easy access.

Chris

Looks like you have installed the flap and aileron gap seals already. Will these have to be removed to fix these rivets?

When the head's messed up like that, I've tended to go from the back side - I've always been able to see the center of the rivet in the shop head as a discoloration. You can also use an undersized drill; I find that a #40 works well for those rivets. That way if you are slightly off-center you still have a good chance of not messing up your hole. You just want to drill deep enough to snap the rivet head off and then you can use a punch to get the rest out.

The gap seal isn't installed yet so that won't be an issue. I have tried once, very unsuccessfully, to back drill a bad rivet. I am a little gun shy to try that. I'm trying to work up the nerve to use the cutoff wheel. Just to be sure I am correct you guys are saying to use a cut off wheel to grind through the bad manufactured head and get down almost to the rib flange so that I can see the center of the rivet?

Thanks for all the suggestions.

HeliCooper said:

The gap seal isn't installed yet so that won't be an issue. I have tried once, very unsuccessfully, to back drill a bad rivet. I am a little gun shy to try that. I'm trying to work up the nerve to use the cutoff wheel. Just to be sure I am correct you guys are saying to use a cut off wheel to grind through the bad manufactured head and get down almost to the rib flange so that I can see the center of the rivet?

Thanks for all the suggestions.

Click to expand...

Yep, go slow, careful not to hit the wheel against anything else, and it's fairly easy. Before you grind it down all the way, you will see an outline of the rivet center, and can stop then and pop it off/out.

Chris

Im with Flion in this situation. I would go from the buck tail side but use the little sanding drum on the dremel tool. Take a scrap piece of .016, drill a hole a little larger than the buck tail, tape it around the rivet and sand the rivet down almost flush with the spar. Clean it up with the sanding disk after removing your protective .016. Drill the center w/#40 drill just enough to relieve rivet pressure. Back it up with a small socket so you don't bend the rib flange and gently tap it out w/ a small punch. Turn down the pressure on your air drill to just get the drill started in the center of the rivet and go slow. Take your time.

As far as the flanges not being seated fully against the spar, I understand how to prevent that with the washer, etc. In this case, from the pictures it does not look that bad. Typically from my experience without the washer trick, the edge of the flange my lift a little but there is good contact area around the rivet. What are people's opinions on wheteher those rivets need drilling out and re-riveting? Is there a structural concern or just an aesthetic reason to ensure the flange is fully contacting the rib? I would agree if the rivet has expanded between the flange and skin it needs to be fixed, but otherwise is it an issue? Just looking for opinions. I know I have a couple places early in my build where the flanges look seated but I can slide a piece of paper between the flange and skin/spar on one side but other side is tight.

Thanks

Drilling out a smiley

One technique that has worked for me is to drill all the way through from the shop head with a small (#50) drill. You should come out the other end near the center.

Now, use the small hole to guide a #30 drill and drill deep enough to snap off the head. You can then either punch the rivet out or, better still, use a pair of dykes to work it out from the other end.

Hey Tom,

Just got off work today (I work 12 hour shifts 7 days on 7 days off). I have the skins on to match drill and CS. Hoping to have it worked out by Thursday. I will definitely let you all know how it went.

Jim

I tried using a cutting wheel to grind off he manufactured head. It was impossible to get to without bumping into the rib or flanges so I put my big boy pants on and decided to give drilling the shop head a try again. I'm happy to say I got it out without any damage to the hole or doubler.

Thanks for the help all.

Nice work.

I have some tiny ball ended carbide burrs from my dremel. I picked them up at OSH a few years back, but after need one, it would be worth full price.

The tiny little unit is much easier to keep under control in tight quarters.

Again - nicely done.