help - riveting problems

[prkaye]

Frustrating night in the shop. I'm at the stage of assembling my Horiz Stab. I got the spars assembled no problem, as these were all squeezed rivets. The task for tonight was to try to rivet the nose ribs into the HS skin. The problems:

1) The first problem was that my clecoes won't hold. I guess from match-drilling and deburring the holes in the skin and ribs, the holes are big enough now that the spring-back force of the rib near the nose is too much for the clecoes to hold... they just go shooting out. Anyone else have this problem?

2) I managed to get it clecoed enough to start trying to rivet the middle nose-rib in place. I had a real hard time getting a feel for this, and ended up botching a couple of rivets. When drilling these out, the holes have gotten enlarged a bit. I don't know if this means I need a new skin and rib, or what. What is the usual way of dealing with this?

3) Also, I'm not sure about the rivets that I "successfully" set... they don't seem perfectly flat and smooth agains the skin... with the edge of my fingernail I am able to "pick at" the edge of the rivet head... is this normal, or should they be smooth as a baby's bottom?

Thanks for any help!

[RV8RIVETER]

Phil

A picture would be very helpful here.

As for the ribs, I am not sure what your problem is from your question. The clecos should hold if the hole size is correct. There should not that much force pushing the peices away from each other, if the nose of the rib and the flanges are all 90deg and everything fits right.

As for repair, if you have a problem with hole size on drilling out a rivet, you can go the next size larger, provided there is the proper edge distance.

Hopefully you can post a picture and am sure you will have all the advice you need, and then some.

[txaviator]

I am of the same opinion as Wade....the clecos should not be popping out unless the holes were all match-drilled with the wrong size bit? Something doesn't sound right. Also, did you be sure all the parts were mating flush before drilling/riveting? Still sounds to me like a wrong sized drill bit!? And/or, you are using the right sized clecos?

I will add that the most forward rivets in the nose ribs are a real bear to buck. I don't have my plans handy, but I recall one or two of the forward rivets being very tough. Don't feel bad about that though....I have seen a few -9's (unpainted) with filler in that exact location

[FlyerJumper]

Check out this thread...

http://www.vansairforce.com/communit...ead.php?t=7412

[prkaye]

pretty sure the drill bit was right... some of the clecoes hold. The larger clecoes (the #30 ones, brass coloured) don't even fit inthe holes
I think maybe i deburred too aggressively???

[DickDe]

Paul...

problem 1...3/32" clecoes hold well in undimpled, drilled holes but will loose some gripping ability once the hole is dimpled partially because the dimpling process enlarges the whole slightly. That and the riveting viabrations causes the clecoes to pop out. 1/8" and larger do not seem to have the problem as severly. Also certain brands of clecoes do not have as well formed tip as others and this is more critical again with 3/32" size. I can't recall the brand but Avery & Cleaveland Tool sells the better clecoes. US Tool and ATS Tool sells the poor quality clecoes and, again, it only affects the 3/32" clecoes.
To prevent popping, try a small piece of tin with an undimpled 3/32" hole acting like a washer on pin side of your clecoe to give the clecoe more gripping power. I would only do this in every 3rd hole or more so the other clecoes in the remaining holes will hold the sheets in proper position. These "washered" clecoes will hold the bent sheets enough to take the strain off the those clecoes without the tin "washer".

problem 2... You need to have some "oops" rivets in those enlarged holes. Van's sells them. They are a rivets with the head of a normal 3/32" rivet but the shank is the size of a 1/8" rivet allowing you to drill the hole out and still have a normal looking head. You may find some nearby builder with some that you can borrow. They are actually an NAS size rivet. Do a search on Van's webstore for "oops Rivet".

Problem 3...You "may" be pressing too hard with the bucking bar at the start of the rivet process. The first hit by the rivet gun should be lighter until the rivet starts to form then a little more trigger along with a little more pressure on the bucking bar until the tail is fully formed. Most newbies use too much air pressure and are too aggressive during the first blows of the rivet gun. Take some small pieces of scrap and practice first. Keep the air pressure low and go slow. You must acquire this skill even though a squeezer does such a nice job because you cannot possibly reach all rivets with a squeezer.

I hope this helps.

Dick DeCramer
Northfield, MN
N500DD RV6 slow build
160 great flying hours
RV4 wreck rebuild also flying
RV8 Wing kit in process

[JohnR]

Cleaveland Tools sells wedgelock brand clecos and I have had a lot better luck with them. They are currently on sale for .31 apiece I believe. At least they were a day or two ago.

[prkaye]

>> try a small piece of tin with an undimpled 3/32" hole acting like a washer on pin side

That's brilliant, why didn't i think of that!

And yes, I think the dimpling caused the problem.

About the oops rivet, what if I need a rivet with a slightly larger head, because the hole in the skin is a bit too wide (kind of like two overlapping holes now)... can I use a bigger rivet?
The plans called for AD3-3.5. i don't have any AD4-3.5 but could i go AD4-4 ?

[az_gila]

Originally Posted by prkaye

>> try a small piece of tin with an undimpled 3/32" hole acting like a washer on pin side

That's brilliant, why didn't i think of that!

And yes, I think the dimpling caused the problem.

About the oops rivet, what if I need a rivet with a slightly larger head, because the hole in the skin is a bit too wide (kind of like two overlapping holes now)... can I use a bigger rivet?
The plans called for AD3-3.5. i don't have any AD4-3.5 but could i go AD4-4 ?

The "OOPS" rivets (or the next larger rivet size) need to be longer than the original.

Remember, you still need 1.5 D sticking out on the shop head side before riveting. Since the "oops" rivets (or next size up) are 1/32 inch larger diameter (33%), you need the exposed, pre-riveted portion to be longer too....

If you go to a AD4-xx rivet, you will also need a larger dimple. Do not countersink your hole as has been suggested in another similar thread. Calculations show that you will remove over 50% of the skin thickness to make the AD4 rivet sit flush in a AD3 dimple.

Lots of high level mathematics could be done, but 0.5 to 1 size up in rivet length should do it....

Buy some of the NAS1097 rivets, you'll need them eventually.....

gil in Tucson

[Pmerems]

First-there is definitely a bad batch of clecos out there. I tested several a another builder had and they all popped out of dimpled holes. He sent them back to Brown tool and they were replaced (no charge). I don't remember the brand of clecos. There are only 2 or 3 manufactures in the US.

Second-If you have not riveted anything more then the middle nose rib yet and you are not happy with the result this is what I recommend. Remove the rivets that you have set. Drill and dimple the middle nose ribs for 1/8 flush rivets (AD4). Install the AVDEL blind rivets that Van supplies with the kit (don't recall the part number). The reason I suggest this is simple. RV-4 middle nose ribs are attached this way, there is very little room to buck safely under the middle nose rib-good change of having poorly set rivets, the skin fit around the nose rib in not great (local builder had the same issue with the skin fit)-very good chance of having a poorly set rivet. I had mixed results trying to rivet my RV-7 middle nose ribs as well.

Blind rivets are appropriate in this location.

Get replacement clecos

Food for thought,

Paul
RV-4/RV-7A canopy