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Leading Edge to Spar rivets

Jonnyb

Well Known Member
Am after some advice
I have managed to screw up one of the rivets that goes through the main spar. It’s got to come out, so the question is how. It’s on the 3rd rib in and to make matters worse it’s a corner rivet.
Has anyone drilled one of these out? Any special tools or techniques?
 

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Technique

I've drilled out similar but not exactly that location, it's tricky to not elongate the hole and make it even harder to set the new rivet. At least your rivet is only partially set so it should be easier to remove.
The key is to drill exactly perpendicular through the dead centre of the rivet.
I use an automatic centre punch first to emphasize the dot in the factory head.
Then use a sharp pilot drill e.g. 2 mm to go almost all the way through. A square can be clamped beside the rivet to help visually guide the bit to be perpendicular.
If the rib is in the way of the drill motor and cannot be flexed to the side then a 12" long bit may help.
After drilling the pilot hole I drill through just the factory head with a 1/8 bit and use the shank of a drill to snap off the factory head.
Then the rest of the rivet should knock out with a small pin punch. Sometimes I use a blunt panel pin knocking in the bottom of the pilot hole to do this.
Take it slowly and carefully and you can do it!
 
It looks laid over almost as if the hole was not round to start with. Give Vans tech support a call. They may have some good advice for you given the nature of the area.
 
Am after some advice
I have managed to screw up one of the rivets that goes through the main spar. It’s got to come out, so the question is how. It’s on the 3rd rib in and to make matters worse it’s a corner rivet.
Has anyone drilled one of these out? Any special tools or techniques?

I drilled a couple of them out before. It's not unlike other rivet removal but you have to be more careful. I also grind down a plier so it is flush with the surface to grab and to wiggle out the rivet from the squishy end (not the shop head).

Other who had trouble with these rivets had tried using the Cherry Max rivets with great success because you don't have put the rivet gun so close to the spar. Vans also recommends them but you have to check with the tech support.

https://www.walmart.com/ip/6-Lineman-Sidecutter-Plier/369355465
 
Thanks guys, it’s coming out today!

Just need to work out how I’m going to get a drill to the manufactured head that’s buried deep in the leading edge, and that I can’t see!
 
Might be easier to drill the rib out next to it as well. Sometimes going back makes it easier and actually less time consuming to move forward.
 
It’s out and reset!
Took a load of inspection mirrors at various angles, a head torch, and a 90 degree drill.
Just hope I don't have to do it again!
 
I’m sure Vans approve LP4-3 rivets for the rib to spar rivets. Obviously solid rivets for the leading edge skin to spar cap.
 
I’m sure Vans approve LP4-3 rivets for the rib to spar rivets. Obviously solid rivets for the leading edge skin to spar cap.

LP4-3? Those rivets don't have near the same strength as solid rivets. Cherry Max, I understand.

Do you have anything to back up this post about LP4-3 rivets?
 
Yes, I do, thank you. I don’t consider myself anywhere competent enough to post my personal opinion on anything structural, which is why my post inferred that if the original poster wanted to hear from the horse’s mouth he may wish to contact Vans directly.

“ Hi Vans,

I've read online that in the past you have approved the use of LP4-3 blind rivets to rivet the leading edge rib rear flange to the main spar web - as you know the technique for bucking solid rivets is a little tricky! I wanted to check that this was an accurate reflection and that using an LP4-3 was strong enough?”

“ Yes, it’s been done many times – you will need some LP4—4 as well in some locations
Vans”
 
I asked Vans and this is the reply I got:

The use of the LP4 rivet has not effectively been tested in this area by Van engineers. The attachment using LP4 rivets is obviously not as strong as using solid rivets but the extent to which the structure will be weakened is probably quite small. This method is used in the RV14 but in that case there are more rivets being used. (6 on the inboard and 8 on the three outboard ribs).

On a balance of probabilities it is likely that using LP4 rivets will be fine but this is still a decision that will ultimately rest with you.

Now we play by slightly different rules in the UK, and this reply means I probably wouldn’t get approval to use the LP4 rivets in this situation. So solid rivets as per the plans was my only option.
 
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