Should I re-do these rivets?

[attackpilot]

I would like some advice on whether I should re-do these rivets on the forward spar of the HS on my RV-10 kit.

The ones I have concerns about are the top one and the third one down. I know the bottom one is chewed up. You can see how the edges of the head are smooshed (technical term) out. All of the shop heads are decent thanks to my wife.

It was difficult enough trying to get a offset rivet set into this area. These rivets attach the backside of the nose ribs to the forward spar through the spar doubler. I have scuffed the rivets with a scotch pad to remove the crud that forms from riveting for better viewing.

Ideally I would replace them, but I never have good luck drilling out rivets and I am scared that I will drill them out and make the same mistake again with a larger hole.

Thanks in advance.

Joe Hutchison

[IMG][/IMG]

[TSwezey]

I would drill out all three. If you are worried about making hole bigger use a #31 drill bit. It's a little smaller but you will find that the smashed heads drill out very quickly.

[alpinelakespilot2000]

Joe-

I bet if you check with Van's they will say they're good enough, perhaps with the exception of the lowest one. Somewhere in RVator there was an article about how damaged factory heads had little impact on overall strength of the rivet. And, as you noted, drilling them out has problems of it's own, especially in this tight location. But, again, I'd check with Van's, at least so that you can sleep better.

One thing that will really help to keep the rivet set square on the head of the rivet (and avoid the "smilies") is to use the "SnapSocs" from Avery. They do a great job. They are a little pricey just for some pieces of plastic, but they sure do work well... better even, in my opinion, than using masking tape over the set, which also works better than nothing. I've never had a bad factory head with them.

Don't worry--you'll get better and better at riveting (and so will your wife!) as you go and those nose rib-spar-main rib rivets are really difficult ones. A lot of other builders in this forum have had trouble here as well. Van's should have you rivet those before putting the skeleton into the skin.

Good luck.

[Brantel]

Hello,

This is one place on all the RV models that seem to give builders problems. I thought that I was a total idiot when I decided to put structural cherrymax rivets in this spot on my 7 emp. I tried to put the solid rivets in there at least 3 times before calling it quits and moving on.

Later I have seen pictures and a couple of other live examples of where the builders did exactly what I did, they gave up and put in the cherry's.

For some reason, that weird place, angle etc. is a real problem for those of us that are not experts with the gun.

[RV_7A]

Leave them alone and move on. They are fine. I tried fixing mine and made them worse. As mentioned before, this is an akward place to work in and difficult to drill them out without making the holes bigger. Its OK really...

-Jeff

[lrfrey]

Joe, I'd drill out the top one and definately the bottom one. As T and Steve said you'll get better. The smiles (and the really chewed up bottom one) are caused by the rivet set bouncing.... yes, you didn't keep pressure on it I know this As the other guys said use a #31 or #32 drill, go slowly just past the head then use a punch (butt of the drill bit) to break off the head. then drill through the rivet (not quite through), put a bucking bar next to the shop head and punch the rivet out. If the hole is to large put the next size rivet in. Keep on going...

Larry

[rv8bldr]

I've found that the solution to driving those AN470AD4-x rivets is to use a piece of hockey shinpad tape over the manufactured head. It is clear, comes off easily after riveting, and prevents the rivet set from bouncing around and making those smiles.

http://www.canadiantire.ca/assortmen...romSearch=true

How Canadian is that ?

Cheers

[vmirv8bldr]

Don't feel bad, this is common.

Personally, I would drill out the top and bottom and replace them, but leave the others. If access is bad, I would opt for the Cherry to prevent making this problem worse. I did a similar thing on my empennage. I replaced the same rivet three times, making the same bad manufactured head every time, due to poor access. Finally, the hole was quite large and the metal was distorted. I had to put in a much larger Pop rivet. If I could go back in time, I would have drilled it once and used the Cherry.

In your emp, The other good rivets are holding quite a bit of structural integrity on their own. I doubt there would be a marked decrease in reliability from the Cherry's in those two holes.

To be sure though, call Van's.

Also when drilling out rivets, I find it VERY helpful to use a spring-loaded center-punch. Put it in the existing dimple on the manufactured head and punch a few times. This will really help keep that drill bit from wandering. I read that tip on a thead here somewhere quite a while ago.

Good luck!

[az_gila]

Some cutting or deformation of the manufactured head is completely acceptable.

You could use this paragraph as a guideline.

5.2.7.5 Marring of the manufactured head. A cut or ring
caused by the riveting equipment used shall be acceptable on non-
flush rivets providing the depth of the cut is not greater than
one-fourth of the head height. Cut or ringed flush rivets shall
not be acceptable.

Info came from this alternate MIL-Spec at a NASA site.

http://mmptdpublic.jsc.nasa.gov/prc/MIL-STD-403.doc

Looks to me that the lowest one should be replaced, and possibly the top one, just like the previous suggestion...

gil in Tucson

[AltonD]

http://averytools.com/pc-528-21-rivet-removal-tool.aspx

AN470 Rivet removal tool .
This does not always work if you have chewed up the head really bad. it should center up on all but maybe the bottom one. I have use it many times and I am glad I spent the money on it. It centers up the drill bit and lets you set the depth of the bit. Works for me.