Why you don't drink while assembling aircraft

Ok,

I can take it. Stupid - go ahead and say it.

I just riveted the elevator ribs, to the wrong skin - backwards.

Now that that is out of the way, how should I fix it? I have drilled out all the offending rivets, and according to the manual, I should use the next size larger for the "re-installation".

The plans call for AN426AD3-3 rivets to attach the elevator ribs to the elevator skins, so I assume I want AN426AD4-3, but Van's only goes down to AN426AD4-4.

Should I just use the -4's, or get a whole new skin and ribs? Will I have any trim issues by using larger rivets on the left elevator vs the right after everything gets put together? I know that it will only be approx 0.05 lbs different, so I assume that I am OK.....

Your wisdon is appreciated.

Greg

Use cheater rivets

Use some "cheater" rivets available from Vans. (Also called "OOPS" rivets) These rivets have the -4(1/8") diameter shank but still have the smaller -3 manufactured head. That way externally you'll be the only one who knows. Except of course, those of us who read your post. They're sold by the pound (or fraction thereof) like the other rivets. I bought a handfull of all four available lengths. Trust me, you'll need more later somewhere or other. Don't ask me how I know. Plus, you can be a hero when your buddy who started building after you needs some and you can educate him, too. The P/N for these are:
NAS1097AD4-3.5 to -6

And don't beat yourself up over it. You'd have to get pretty creative to make a mistake that hasn't already been done. Keep hammerin'.

--hawk

Yes, Greg, been there ...

So, I now have a list of things that I don't even think of doing after the first beer, and a list of things a do while drinking beer.

Never drink and...
1. rivet (smiley faces in VS to remind me)
2. cut peices (angle brackets for HS rear spar)
3. drill holes/Counter sink (Rudder AEX wedge counter sunk too far)
4. shop for tools on-line (two angle drill attachments)
5. work w/ proseal (hours of cleaning up the proseal off rudder)
6. dimple (extra hole w/ dimpler in VS rib)

DO drink and
1. deburr
2. scuff
3. alumiprep / alodine
4. prime
5. read the manual
6. sweep the floor

As for your particular situation....

gregbazar said:

Ok,

The plans call for AN426AD3-3 rivets to attach the elevator ribs to the elevator skins, so I assume I want AN426AD4-3, but Van's only goes down to AN426AD4-4.

Should I just use the -4's, or get a whole new skin and ribs? Will I have any trim issues by using larger rivets on the left elevator vs the right after everything gets put together? I know that it will only be approx 0.05 lbs different, so I assume that I am OK.....

Your wisdon is appreciated.

Greg

Click to expand...

Providing that the distance from the rivet holes to the edge of the material is not too small, I'd use the -4's. Dimple appropriately for the -4's and I can't imaging that the effects of using different rivets on one side vs. the other would be noticeable. Of course, if you are extremely paranoid about using different rivets on each side, you could always upsize the rivets on the other side too.

Other side is already done...

With the oops rivets do you have to re-drill and re-dimple every hole?

The holes that I tried with 4-4's accepted the 1/8" shank OK, but the dimple was wrong (being it was setup as #40 for 3-3's).

I assume if I use the 4-4 rivets I will have to re-drill and re-dimple?

My 2 cents.....you're building an expensive aircraft. Why shortchange yourself for a couple bucks?? You will most certianly 'ooger' up a couple of the holes in the skin and/or the ribs while drilling out that many rivets.

An oops rivet here or there is OK....but......spend a couple bucks and get a new skin and ribs....you WILL be glad you fixed it RIGHT.

Rick Gray in Ohio at the Buffalo Farm - RV6 Sold, RV8 Project Completed, RV10 and F1 Rocket Under Construction!!

I'd call Vans and ask them. I suspect they're gonna say to just go ahead and rivet the correct skin on with 3/32 rivets, use oops rivets in the really bad holes, and move on. The rivet will expand a bit to fill up the holes that aren't too bad.

re: oops rivets. No redimpling...just redrilling. The dimples should fit fine.

I'm with Rick

It's not worth it to try to un-do it when the replacement parts are so easily available. I've bought a few myself.
Just my 2 cents as well.

I seem to remember reading that the oops rivets do not have the same strength as the regular ones and are for "non-structural" use. I believe this is due to the fact that the shank of the rivet is wider, but the head is the same, so the contact area between rivet head and skin is reduced.

Just curious, why do you have to go to bigger rivets? I can't recall ever reading that requirement.

Steve Zicree
RV4 finishing

Bigger Rivets

I am not sure if I picked that up from the manual, or from the EAA RV Builders class.

Either way, the holes are definaltly bigger, after drilling out the old rivets with a #40 bit. 1/8" shank rivets fit in most of the holes, even though they were only drilled to #40 before the 3/32" rivets were installed.

I think, since I have extra 4-4 rivets, I will just drill out the holes and try it. If it doesn't work, well I can always buy a new skin and ribs.

Update --

Turns out the couple of holes that I checked were the worst. Almost all the others won't take a 1/8" rivet. I have attached a couple pictures.

This won't help too much now, but for the future:

When drilling out 3/32" rivets, use a #42 bit and don't drill all the way down the rivet. Just put a 3/32" punch into the hole and pop the top of the rivet off.

You'll never (well - almost never ) have an oversize hole again.

gregbazar said:

................The plans call for AN426AD3-3 rivets to attach the elevator ribs to the elevator skins, so I assume I want AN426AD4-3, but Van's only goes down to AN426AD4-4. Should I just use the -4's, or get a whole new skin and ribs? Will I have any trim issues by using larger rivets on the left elevator vs the right after everything gets put together? Greg

Click to expand...

Greg,

It is pointless to scrap those parts if they will accept AD4 rivets. Assuming that condition exists and no other damage was incurred, your fix is very easy. For those holes not wallowed out and still acceptable as #40 holes, slightly pre swell AD3-3.5 rivets with a hand squeezer as illustrated in the photo and reinsert into the subject holes. Set normally.
For oversize holes, bring the hole up with a #30 drill bit. Leave the dimple alone, then install NAS1097AD4-3.5 rivets. The rivet head is so close in diameter to that of an AD3 rivet as to be negligible.

It is a virtual given in sheet metal practice to bring holes oversize as required. In fact the only thing keeping you from bringing some of those holes up to a mind blowing .160 (5/32" AD5 rivet) is e.d. issues, finding the proper dimple to work the parts with and then living with the butt ugly result!

Personally, I was never comfortable with Van's supplied AD3-3 length rivets. Every situation I've encountered to date requires a minimum length of -3.5. Naturally, others may disagree.

From what I've discerned reading your post, no show stoppers resulted from your ill-advised drinking binge and as the good folks at Van's would say...."Build on!"

If you still have doubts....Van's is a just a phone call away.


Rick Galati RV-6A "Darla"
RV-8A empennage complete