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Pulled rivets on a RV-10

barryrv10

Well Known Member
Our EAA chapter has been given a RV10 kit that was put together with 1/8" CS4-4 flush alum with carbon steel shank rivets. We are trying to figure out how this will effect the price if we chose to sell the kit. I think it will be strong enough, but it will be a "one of a kind" bird; and please do not ask why the pulled rivets, cause we do not know. Blue Skys Barry
 
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Need more information. Is the entire airframe this way? Or just the tailcone?
Were 1/8" used instead of 3/32"? Everywhere? What do edge distances look like?

IMHO you may have inherited a piece of junk. Unless you have new members who want to learn by drilling them all out and starting over.
 
IMHO---- No longer an RV-10! It's only value is to a salvage yard. I hope it will be destroyed so someone in deep denial will not try to finish it and hurt someone. Where does this stuff come from is my question?????
 
My personal opinion is that not only would it impact price, many potential buyers may not consider buying it all all.

I can't imagine going through the effort of drilling out all the pulled rivets and replacing them with an4s.

I'm curious, did they use pulled rivets on the tanks too?
 
I think this should be a question for Van's regarding structure. It will certainly be heavier and not as nice-looking. Resale value, no matter what Van's says about it structurally, will greatly suffer.
 
Pulled rivets in fuel tank

Hi Bob, I have not seen the parts, but one person who inspected them thought cherry max rivets were used in the fuel tanks
 
Pulled Rivets

Sell the plane , list it on Barnstormers as a 4 Seat RV12 .

It might not look the best but see what Vans has to say .
 
I am still not sure I understand. Are the CS4-4s used in place of AN426-3 rivets or everywhere? In any case, I would agree with the advice to check with Van's regarding airworthiness. If I were buying, that's what I'd do as a buyer, though it would also make me inspect the craftsmanship VERY carefully even if Van's Ok'ed the substitution. And there is no way I would accept pulled rivets in the structure. I know you don't know the why but I'd sure love to know what was in the builder's mind; that's an expensive kit to render into probable scrap aluminum like that. Perhaps that's why you inherited it? Maybe the builder came to realize his error?
 
Perfect Opportunity!

..to build a simulator for your EAA Chapter! I would think you'll get a heck of a lot more "mileage" out of that bird by turning it into a great learning tool. Lemons to lemonade people..
 
It sounds like all the holes, many of which were designed for 3/32" rivets, have been drilled to 1/8" diameter, dimpled, and filled with a pull rivet whose grip length range may or may not have been ideal for the material stack-up.

I'm not sure how anyone can look at a closed tail or wing structure and quickly make a determination that all edge distances are good.

Additionally, CS4-4 rivets have no positive stem retention feature like CherryMax rivets do. All structural evaluation therefore must assume that the stem does not contribute to the shear strength. Compared to an AD-material solid rivet of the same diameter, I would bet the CS4-4 is substantially less robust. Exact data on many of the Vans pull rivets is hard to come by though.

I agree with turning it into a museum piece or ground simulator.
 
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Rivets

Yeah, I have looked quite a bit for specs on the CS4 rivets to no avail. I did find some data on countersunk aluminum rivets with a mild steel shank, though. The shear strength was 170 lb and tensile was 220 lb. Note that is lbs and not the psi that the AN426 rivet strength are listed at...

And they are definitely NOT Cherrys or other structural rivets.

It is amazing that this would come up but I guess I am not surprised. An A/P that I know did a pre buy for a guy buying a 152. They buyer's pilot FLEW the airplane in for the pre buy. A short time into the pre buy, the A/P noted that there had been quite a bit of damage history on the airplane. Upon examining the repairs, he found that ALL of the repairs were completed with hardware store pop rivets...and a substantial amount of the damage was to flying surfaces, including the spars...:eek::eek:
 
Yeah, I have looked quite a bit for specs on the CS4 rivets to no avail. I did find some data on countersunk aluminum rivets with a mild steel shank, though. The shear strength was 170 lb and tensile was 220 lb. Note that is lbs and not the psi that the AN426 rivet strength are listed at...

And they are definitely NOT Cherrys or other structural rivets.

Various sources list AD material rivets (2117-T4) as having shear strength of 26,000 psi. To get the single shear capability of the rivet, find the cross-sectional area of the rivet (for a 1/8" rivet it is .0123 sq. in.) and multiply by 26,000 psi, for about 319 lbs.

Keep in mind that static fastener shear is not the only way a joint can fail, so please don't use this as any sort of joint analysis that you risk your life on. This is simply an illustration to show that the 170 lb shear for the unknown pedigree pull rivet that rocketman found can be vastly different from the strength of a real AN or MS-Spec solid rivet.
 
You will find the rivet details here. Apparently Van's has their own naming system.

The 3/32 bucked rivet has a shear of 179 lbs. The 1/8 Gesipa has a minimum shear of 170 lbs.

Tony

The above isn't correct, it's not just 26ksi*Area of a 3/32 dia circle. A 3/32 AD rivet has a shear strength of 217 lbs when driven because a) the material expands to fill the #40 hole (.098") and D is therefore not 3/32 (.094") and more importantly b) the material work-hardens when being driven. I only point out the difference because in this case it'd make the comparison slightly non-conservative.

If the 3/32 AD's have a shear strength of 217 and the blind 1/8 have a strength of 170, that's red flag #1, red flag #2 is that a much bigger rivet has a much lower strength, which means the blinds aren't getting any strength from their stems like a cherry max would. This means they'll work loose VERY quickly in a fatigue situation resulting in skin cracks, smoking holes and maybe even water intrusion.

I think you should donate or loan this to your local Air Force base or Tech school so that some students can learn how to drill out rivets and/or practice ABDR (acft battle damage repair) because once all the holes are drilled out, some will inevitably need to be replaced with 5/32" and surely by then edge deistance will start becoming an issue.

I'd be interested in seeing picture of it....
 
Aw, I bet if you just drill between each existing rivet and double up on the pop rivets you'll be good to go. I suppose the glass work is up to the same high standards.
 
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