Efficiency vs potential quality when backriveting

ToadMan8 · #1 08-13-2012, 01:40 PM

I finished attaching stiffeners to the first rudder skin by clecoing the stiffeners on, then removing a few clecoes at a time, putting in rivets, taping, flipping the skin, riveting, flipping it back over, removing a few more clecoes, etc. That works well, but takes a long time with all of the flipping it over to do a few at a time.

Is there a reason I shouldn't put a few clecos in on each end of the stiffener, place and tape all the rivets in between, flip and rivet in one go? If the manufactured head is neatly in the dimple and the tail is standing straight up, I'd think I'm good to go?

As an aside, I find this one of the most difficult aspects of being a new builder (not working at an airport with a bunch of tech councilors all over), trying to decide what is necessary quality and care and what is just time wasting.

Thank you for your thoughts!

n82rb · #2 08-13-2012, 01:48 PM

on stiffeners, i just put all the rivets in the holes,taped them in place, turned it over and placed the stiffener in place and held it down and back riveted it in place. I never used clecos when back riveting the stiffeners.

bob burns
N82RB RV-4

SilverEagle2 · #3 08-13-2012, 01:51 PM

I taped a whole row, flipped the skin and set the stiffener in place. The dimples and the back rivet set should line everything up and center the rivet in the hole. No need to keep flipping.

Mine turned out great, but I am a novice.

WAM120RV · #4 08-13-2012, 01:58 PM

Toad,

What the others said........ you are wasting your time doing what you are doing and getting an inferior end result in the process.

All the stiffeners should be back riveted and if you can back rivet anything else it will produce a better (flatter) finish. I back riveted my upper wing skins with a long offset back rivet tool.

Before you do anything ask on this forum first. people are more than willing to help you with best practice. We have all made mistakes on the way so try to help others avoid the same mistakes.

ToadMan8 · #5 08-13-2012, 02:08 PM

Quote:

Originally Posted by WAM120RV

Toad,

What the others said........ you are wasting your time doing what you are doing and getting an inferior end result in the process.

All the stiffeners should be back riveted and if you can back rivet anything else it will produce a better (flatter) finish. I back riveted my upper wing skins with a long offset back rivet tool.

Before you do anything ask on this forum first. people are more than willing to help you with best practice. We have all made mistakes on the way so try to help others avoid the same mistakes.

Hey, thanks

I appreciate your advice, and will ask more readily in the future!

FlyingArcher · #6 08-13-2012, 02:29 PM

Hi Toad,

Have a look at the bottom of this page on Cleaveland tools web site,

They present a series of videos called Back Riveting 101 that I found very useful when I was at your stage.

Cheers

Flying Scotsman · #7 08-13-2012, 03:19 PM

Don't get so excited setting one rivet right after another along a stiffener that you try to set one that is *not* on the metal back rivet plate. I'm certain literally thousands of builders will concur with this advice

smiller · #8 08-14-2012, 09:23 AM

Oh I've topped that. I once was so excited backriveting one rivet after another that I taped in a row of rivets, set them, and did the same for a whole 'nother row, before realizing that I had forgotten to place the stiffeners! The rivets securing nothing to the skin were sure beautiful, though! =D

ToadMan8 · #9 08-14-2012, 12:19 PM

Quote:

Originally Posted by smiller

Oh I've topped that. I once was so excited backriveting one rivet after another that I taped in a row of rivets, set them, and did the same for a whole 'nother row, before realizing that I had forgotten to place the stiffeners! The rivets securing nothing to the skin were sure beautiful, though! =D

Awww, that's awful! Oh well, hopefully they drilled out cleanly!

smiller · #10 08-15-2012, 09:10 AM

Quote:

Originally Posted by ToadMan8

Awww, that's awful! Oh well, hopefully they drilled out cleanly!

All but two. After partially drilling through the manufactured head side, popping off that head, and "working" the rivet out, I saw that I had tiny cracks leading from two of the holes to the skin area. For one, the crack was so short, I simply enlarged the hole to #30 and used an "oops" NAS1097 rivet. For the other, the crack was too large for that solution. After talking to my Tech Counselor, I enlarged the second hole to I think around 1/4" in diameter (ouch! very difficult psychologically!), then I drilled two new #40 rivet holes on either side of it (with proper edge distance). With the stiffener installed the 1/4" hole is covered. The recess will be filled later with epoxy. It's on the underside of the elevator, the repair should not have any noticeable effect on weight/balance, and once it's filled and painted nobody will even be able to see it.

Doing a repair like that -- painful as it was -- was a good lesson for me. It reminded me of what more experienced builders have told me: the vast majority of mistakes made while building our airplanes are repairable. In my early days of building, I would have bought new skins and stiffener angle and started them over again.