Would you replace this rivet?

A place to chuckle at yourself and share lessons learned the hard way.
Post Reply
tshort
Class C
Posts: 618
Joined: Tue Nov 30, 2004 12:56 am
Location: Indianapolis, IN (KUMP)

Would you replace this rivet?

Post by tshort »

It is one of the rivets that attach the LE ribs to the spar. These were exceedingly difficult to get a rivet set on - I ground the crap out of my offset set (all the way to the cup) and still the fit was no good. Bucking etc was no problem just that I couldn't get the set on well.
In any case, this one rivet sucks:

Image

Image

The main issue is that I am sure attempting to drill this rivet will cause harm. There is no way (even with a 90 deg drill) to easily come straight at the rivet. I'm thinking that since pulled rivets are OK here leaving well enough alone might be the best course...

Thomas
Thomas Short
Indianapolis, IN (KUMP)
RV-8 wings

User avatar
captain_john
Sparky
Posts: 5880
Joined: Sun Oct 31, 2004 9:17 am
Location: KPYM

Post by captain_john »

Yup! As WS and I say, "That one's a drillah"!

You can do better. Of course, if you repeatedley set one bad rivet after the next, you should keep a marginal one if the repeated setting process is detiorating the neighboring material to the point of no return.

These neighboring rivets look good, so it is possible to do properly.

Now, from the looks of this rivet I would say that you were just simply not sqarely set on the rivet head.

You seem to be trying so intently in getting closer to the main rib that you in fact got too close!

In driving these rivets with success, it is VITAL that the set be in line with the shaft of the rivet. Ideally, the shaft will be perpendicular with the surface of the material. This isn't always the case in thinner material, but with these, it is.

Take the rivet set (removed from the gun) and a AN470 rivet and sit in front of the TV and play the rivet on the business end of the rivet. Look at the way it sits on the set and notice that it leaves an edge all around the rivet exposed. You need to keep this image in your mind's eye before pulling the trigger! Keeping the set in this position will give you PERFECT results EVERYTIME!

Drill this one and try it again. You would probably be fine with it, but these are really not that hard to set. You can do it!

Also, if the hole gets too large you can pull out your squeezer and fatten up a longer rivet. This essentially creates an oops rivet and makes it easier to buck what is really a longer rivet.

Do ya knowwhatta mean?

:oops: CJ
RV-7
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!

tshort
Class C
Posts: 618
Joined: Tue Nov 30, 2004 12:56 am
Location: Indianapolis, IN (KUMP)

Post by tshort »

Even with the offset rivet set ground down all the way there is no way to make the set completely perpindicular. Hence the marks in the primer on the main rib - the ground off part of the set is up against the rib. I wasn't actually too close - the smilie on that rivet is concave away from the rib. The rivet set on those rivets never sits quite square even tho it is ground down well... some ribs are worse than others.

If I thought I could drill that easily with no screwups I would in a heartbeat. I'm just not sure there is a good way to do so...

I agree that these are not that hard to set, but if I were designing the layout I would give even 1/8" or 1/16" more which would make a huge difference. Wonder why they did it that way?

T.
Thomas Short
Indianapolis, IN (KUMP)
RV-8 wings

User avatar
captain_john
Sparky
Posts: 5880
Joined: Sun Oct 31, 2004 9:17 am
Location: KPYM

Post by captain_john »

Thomas,

I agree that the rivets are difficult, at best due to the design. No doubt about it!

The smilie is on the rib side. That is an indication you were making contact with it there. In other words, you ground enough off the set and are close enough to the main rib.

All that is needed now is alignment and hammertime!

Tip (which you may already know):

Tape the set to the gun to prevent rotating in the gun.

This is one of those places where I feel dwelling in minutia pays off!

Rivets are small and you need to think precision in order to set them well.

I know how you feel. The other side of the rivet is my Achilles heel!

:oops: CJ
RV-7
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!

Spike
Chief Rivet Banger
Posts: 4013
Joined: Thu Oct 14, 2004 8:40 pm
Location: Baltimore, MD
Contact:

Post by Spike »

Just some thoughts here....

Drilling out that rivet means drilling through the web of the spar. Id make sure you were comfy with that idea first. I think personally I would consider leaving that one if this problem does not become a habit. While the head may not be setting flush the rivet shank may very well have swelled tightly all the way around the hole. If you screw up the hole when drilling out the rivet you may oblong it, etc, such that the new rivet may not fill it up. Just a thought.

If you do drill it, would one of the 24" bits help? That may let you keep the drill outside of the structure.

A large offset on the gun may help, but it does look like you already were able to get onto the rivet plenty, enough to round off to the other side as CJ pointed out.

- John
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl

User avatar
Wicked Stick
Class B
Posts: 1000
Joined: Wed Feb 09, 2005 10:00 pm
Location: KEWB

Post by Wicked Stick »

Thomas,

IF, you can get a #31 bit centered on the head to drill it. Just drill deep enough to snap off the head without drilling through to the spar. Just be sure to back up the leading edge rib with a bucking bar, so that you don't bend the rib's tab away from the spar when your punching the rivet out.

Then, try another solid rivet and see how it goes. If it still ends up poor, why not put a cherry max in there.
Dave "WS" Rogers
RV-8 (125 hrs & counting)
N173DR

User avatar
cjensen
Whiskey Victor
Posts: 5275
Joined: Sat Apr 23, 2005 10:36 pm
Location: Green Bay, WI

Post by cjensen »

Man! I didn't even try bucking those! I used blind for all of 'em...

I'd probably drill it, and pop it. 'Course that means grounding down your puller to get in there... :roll:
Chad Jensen
Missing my RV-7...
Vertical Power support
920.216.3699
http://verticalpower.com

User avatar
TomNativeNewYorker
Class D
Posts: 439
Joined: Tue Mar 21, 2006 9:19 pm
Location: KSAV

Post by TomNativeNewYorker »

Can you drill it out from the bucktail side?

If so, I would drill it out from the back side and try moving the head to the backside and putting the bucktail where the head is currently at.

tshort
Class C
Posts: 618
Joined: Tue Nov 30, 2004 12:56 am
Location: Indianapolis, IN (KUMP)

Post by tshort »

captain_john wrote: The smilie is on the rib side. That is an indication you were making contact with it there. In other words, you ground enough off the set and are close enough to the main rib.
I don't know if I can explain this ... don't have a pic.
As I see it, there are a couple (or more) ways to smilie this rivet - one if the set is too far past it towards the rib and one if it is not on the rivet enough. Maybe it is not clear in the pic but this is the latter - the smile curves "away" from the rib. To me, this means the set was not fully on the rivet. I know this is the case because with the other rivets on this rib it did not seat fully and was not quite perpendicular (because the rib is in the way) - I was just lucky that the set did not move on those.

Tom- no real way to drill it out from the other side, the bucktail is inside the LE which is closed and mounted on the spar. Likewise, shooting from that side would be next to impossible.

Chad - I considered pulled rivets on these, but really had no problems except this one mess up while bucking so I went with solid rivets.

Still considering...

:?

T.
Thomas Short
Indianapolis, IN (KUMP)
RV-8 wings

prestwich
Class D
Posts: 317
Joined: Fri May 20, 2005 8:36 am
Location: Santa Barbara

Post by prestwich »

Thomas,

If it were me, I'd leave it. I've got a couple of ugly rivets in my HS. Given the difficulty of removing and replacing it, it seems that the chances of making it worse are better than the chances of making it better.

Attempt perfection through the use of process control, but don't expect 100% of your rivets to actually end up perfect. I doubt that I'll get much concurrence on this one, but I'd walk away happy with what you've got...

Jon

Post Reply