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embarrassing photo

Jwputnam

Well Known Member
I am learning about riveting the hard way I am afraid. I have made more than a few ham handed riveting errors that show up as dents and bruises, but I have corrected almost all of them. The painter is going to have to do the rest I suppose.

One of them does concern me, so I am posting this photo for comment, as much as it pains me to display it!

This is one of the attach angles on the H/S of my 9A. I screwed up the first angle and made a new one, but had to enlarge five of the nine rivets because I expanded the holes too much when removing them. (I now use a removal tool that prevents this.) I replaced those five AN470-4s with AN470-5s and mistakenly grabbed a 3/16 rivet set (thinking it was a 5/32) and hammered away. Note the beautiful full smiles. (Why does this happen to me so often? BECAUSE I AM AN IDIOT!!!!)

I have shown this to "experts" and the opinions range from "build on" to "replace the H/S", since further rivet replacement will surely create even more damage. I want to believe as one expert said, "It is not anything particularly terrible and it is unlikely that they will cause trouble."

Here it is. I am hiding behind the computer screen.
IMG_2388.JPG
 
John, When you get home I will come and look at it, also, I have and A&P that can look at your empennage kit.:) He also built an RV-9A.

Jim
RV-9A Flying
 
I am learning about riveting the hard way I am afraid. I have made more than a few ham handed riveting errors that show up as dents and bruises, but I have corrected almost all of them. The painter is going to have to do the rest I suppose.

One of them does concern me, so I am posting this photo for comment, as much as it pains me to display it!

This is one of the attach angles on the H/S of my 9A. I screwed up the first angle and made a new one, but had to enlarge five of the nine rivets because I expanded the holes too much when removing them. (I now use a removal tool that prevents this.) I replaced those five AN470-4s with AN470-5s and mistakenly grabbed a 3/16 rivet set (thinking it was a 5/32) and hammered away. Note the beautiful full smiles. (Why does this happen to me so often? BECAUSE I AM AN IDIOT!!!!)

I have shown this to "experts" and the opinions range from "build on" to "replace the H/S", since further rivet replacement will surely create even more damage. I want to believe as one expert said, "It is not anything particularly terrible and it is unlikely that they will cause trouble."

Here it is. I am hiding behind the computer screen.

Of course call Vans for confirmation, but that is not a condition that I would call acceptable workmanship. Additionally, the edge distance to the rivets on the right-most column of rivets in your photo looks to be inadequate.

Chuck that 3/16" rivet set in a drawer far, far away from your other rivet sets and forget about it. You will not need it in your RV9 build. Additionally, keep the 5/32" rivet set separate from the others in a special case in a cabinet somewhere, only to be retrieved when a mistake has been made and a larger 5/32" rivet is called for in repair. That is the only time you would need a rivet set that large.

Slow down and think things through, and measure if needed, before acting. This isn't a race.
 
Also, the deep scratches are definitely cause for concern.

And is that a head standing above the surface? Hard to tell. It's in the upper right of the photo.

Dave
 
Jim,

Thanks. I welcome an A&P to examine my "handiwork".

Doug,

The camera accentuates. You can't get a razor under that rivet. It is flush. I noticed it as well and magnified it in good light. It would appear to be a shadow. The scratches that you see are not in the metal. I noticed those as well and under examination, appear to be little runs in the epoxy primer that are shadowed by the flashlight.

The issue that concerns me is the denting (smile) left by the over sized rivet set. The dents are not easily discernible to the (my) naked eye, but they are definitely there and they bug the **** out of me.

I posted this because I am such an anal worry wart and because I have not had the benefit of a builder to guide me, which I most definitely need! I am going to take Jim's advice (my neighbor that I found luckily through the Minnesota RV Builders) and have an A&P examine my work. I may have made more errors that I haven't discovered yet. I hope not. This one is enough!

Thanks for the response......very much.
 
I did check with Vans. I did not post their reply as I did not feel that they would wish to be quoted, but maybe not. They thought it was certainly ugly, but "not terrifying" and "unlikely that they will cause trouble...but nothing's certain."

Again, I'll have the A&P look at it.

Thanks very much.
 
Riveting

Early on in my build I had a lot of trouble with an AN470-4 rivet on the counterbalance of my horizontal stabilizer. I think I ended up replacing the rivet 4 or 5 times. Horribly frustrating. I had bought a quite expensive 2X rivet gun which said it could set -4 rivets, but after I tried a 3X gun of the same manufacture it was obvious that the 2X just didn't have the energy to properly set -4 rivets. Subsequently I have used the 3X gun almost exclusively.

Long intro to my points:
1. Make sure you have a rivet gun that puts enough energy into the rivet to set it with a few blows. Try a few other builder's guns to get a feel for them.
2. Practice with the gun you have, experiment with the air pressure regulator on your tank (mine is built into the trigger).
3. Practice on non critical parts or make some test pieces to practice on.
4. Make sure the subassembly is secure before riveting.

Riveting is not hard, but it does take some practice. Hope this helps.
 
All good points.

I have a 3X gun, but I must do a better job with pressures. The gun has some sort of adjustment gauge on it that you can dial from 0 through 6, but I am not sure what it does really. Supposedly it adjusts the hitting power, but I sure can't feel it. I set the pressure at the compressor at 40, but that seems to hit far too lightly. I bump it up to 50 and that feels better. More for the large rivets.

I have purchased the videos and watched them several times. I can hear when the gun is hitting a good rivet.

The pneumatic squeezer is my best friend so far.

I have practiced many, many rivets and I do fine until I run into a tight spot or an unusually difficult angle. I have finally learned not to force the issue and use a blind rivet instead of denting the thing all up trying to be perfect.

There is just too much to learn without guidance for me at least.
 
Smileys

My opinion but if Vans didn't commit and say it's ok, I would replace.
Get some time with a mentor and your tools.
Every gun is different. For example my Sioux 3x takes 30 psi for #4s and 20 psi for #3s.
The one thing that helps a lot is mass behind the rivet. Tungsten bar really cuts down on the gun pressure. You want the rivet to set in 1-2 Mississippis.
Use a piece of gorilla tape to protect the rivet and part.
 
Without a doubt, I would replace. You were talking about a major structural attachment component. There should be no question on these types of parts about workmanship. My rule has always been that if Van's does not commit either way I replace the part.
 
It was obvious that the 2X just didn't have the energy to properly set -4 rivets. Subsequently I have used the 3X gun almost exclusively.

My tech counselor told me the same thing after I had trouble with a 2X gun. In fact, he recommended I use a 4X gun with the pressure turned way down for -3 and -4 rivets. His reasoning was that the 4X gun hits much slower than a 2X gun, so it's less likely to bounce around. The 4X sounded like overkill, but I borrowed a 4X gun and my riveting improved almost instantly. I then sent my 2X gun back to Bob Avery, and he converted it into a 4X gun by changing out a few parts.
 
Every time I've agonized over the replace or move-on decision, as soon as I decided to replace, a weight was lifted off my chest and I stopped stressing. There may come a point where replacing isn't nearly as simple, but in this case all it takes is a new spar and some aluminum angle.

Also, consider building the VS first, as many have suggested; it is simpler than the HS.

There will be plenty more rivets in tough spots. Practice with your offset and double offset rivet sets and you will be able to set them all without blind rivets. Admittedly, I have a couple over-size cherry-max rivets hidden in the plane where I managed to screw something up, but I'm betting on my next plane I wouldn't need em. It's a learning experience, and you'll get much more confident as it goes!

Chris
 
It would be wonderful if it were only a spar and an angle. I am afraid that it would require an entire H/S. There is no way to replace that forward spar without tearing the entire H/S apart........which I may yet do, but only after I have an A&P examine it. There may be a fix that I do not see yet.

It would be easy enough to drill out the rivets and produce a new angle, but as one builder pointed out, the edge minimum is not met by two of the oversized (AN470-5) replacement rivets and the holes are already through the spar. I don't believe that the angle can be widened there either.

I have completed the empennage. I have this problem to resolve before I move on.

Thanks for your help.
 
Rebuild

John
It sounds horrible but disassembling an HS is not bad.
I drilled mine apart and replaced the forward spar and all the SB parts. 40 man hours total including priming new parts and reassembly.
One egg shaped hole. Glad I did it.
 
Sorry, I didn't realize you were that far along. Dirty secret: I built a brand new HS just recently; was never happy with mine. After building the rest of the plane, it was easy. It will get easier for you as well, no matter what you decide.

Chris
 
I worry about drilling out the flush rivets. 90% drill out just fine. 10% are a nightmare and leave an oval hole if I can get them out at all. They become OOps rivet candidates. Not good.

I will probably rebuild. We'll see.

You know Chris, I really don't mind rebuilding the H/S. I have some small dents in the leading edge that irritate me and a few nose rib rivets that simply did not set flush enough so that my finger doesn't catch on them even after repeated replacement for whatever reason . What I worry about is screwing up another one! I may not be the right guy for this project. I am not sure yet.

What parts did you order for re-making your H/S? How do you order them from Van's? I don't see anything on their website ordering page for replacement parts. (I might be able to reuse doublers, ribs, etc. if they remove cleanly.

Thanks.
 
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JW,

Someday when you are at 10k feet and going through a bit of turbulence will you be wondering about how your empennage is doing?

Don't be embarrassed. A lot of Builders have rebuilt part or all of a horizontal stabilizer. I did because I didnt like the looks of a couple nose ribs. 10 years later I still have the old mangled parts in my garage reminding me that a few extra dollars spent way back then make me feel much better while flying now!

To this day , given the many many builders who have recommended this after learning the hard way, I have no idea why vans has not changed their instructions to have builders start with the much easier VS. I hate to suggest that it is because they sell lots of replacement parts this way, but some days I really wonder. The lack of simple updates to plans is the only gripe I have about vans.

If you've not already done so, a build class is well worth the money. You'll make it back in parts you don't have to replace later. Good luck with whatever you decide to do though.

PS... If someone were looking to buy an already built RV, they might think twice if they saw those because they would wonder where else there might be similar but more hidden issues. I know most of us don't build with the intent to sell, but even if we are not serial builders, we're all one medical away from having to do so. Just another thought. Again, though, hang in there. We've all messed up parts.
 
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If you were closer, I would make you a really good deal on a completed HS that I bought and never used (long story). Put a "Wanted" add up and see what might be available. Somebody might have one collecting dust in their garage or hangar.
 
I am going to reluctantly rebuild. I will disassemble and see how many parts can be saved in good condition. I am hoping that I can get by with one half of the forward spar, a new doubler, maybe two nose ribs. Might buy new skins because I dented them a little in the nose, which begs the question: How the heck do you buck those nose rivets successfully? I used the tungsten bar wrapped in a rag and thought that I was very careful, but I couldn't make good enough FLAT contact on the rivets in the nose and wound up with small dents.

I'll research on the forum I guess.
 
John, hang in there and don't get discouraged. The reason we start on the empennage is because the overall cost of parts is cheap and we all go through this learning curve. By the time you get your wings finished, you'll feel so much better and know so much more and your confidence will soar. You can always come back to the HS at a later time. If you can get a few hours with an experienced builder to show you some tips, it will help immeasurably! :)
 
Hi Bruce! Good to hear from you.

My thoughts exactly. I am going to look for an instructor when I get up to MN in a few weeks. I'll order my new parts, prepare them and then have him help me with the riveting.
 
It's Already Been Mentioned, but...

Get a heavier bucking bar. Tungsten is the Cadillac, but what you really need is more mass. A powerful rivet gun and higher pressure still won't work if you use a featherweight bucking bar. Once the active/reactive components are matched correctly, it just takes a little practice. Good luck.
Terry, CFI
RV9A N323TP
 
Get the tungsten bucking bar!

Also, you may want to research riveting. My tech counselor gave me a riveting reference that described many of the common errors. They also tested the "error" rivets to compare the relative strength to a normally driven rivet. Their data showed that in most cases, you do more damage trying to drill the rivet out than to leave a minor "error" rivet in place...

That being said, I would probably replace your part. Worth the piece of mind to me...
 
First of all no shame in singing out a potential safety issue. This is why we have such a good safety record. Thank you for setting a high bar. I posted a picture of a butcher job I did on a wing rib with a uni bit drill.

That said. If I were to buy an RV, this spot would be an early check and after looking At yours I would politely walk away. It's an important structural member, which is why it has so many rivets in it.

I buggered up one of those rivets with a big smiley, drilled it out, re squeezed and another smiley. Ended putting a bolt on it. But I didn't leave it

Keeping driving rivets, it is worth it.
 
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Thank you all so very much. I have received several offers to teach me riveting when I get back up to MN for the summer and I am going to take them up on it!

I did research riveting the H/S nose ribs and did not come up with anything that would likely be a sure fire solution. I liked the tip about putting a small piece of fuel hose over the rivet stem to help press the rib flange down (I am guessing.....kind of like what the back rivet set does). Another suggested beveling a bucking bar and yet another suggested using a yoke as a bucking bar, but I can't see how that would fit or work. My nose rib rivets did not set totally correctly and I dented the leading edges as well.

I am hoping that my rivet instructor will be able to clarify.

Thanks to all again.
 
Hang in there and don't get discouraged. I personally replaced those brackets 4 times before I got them right. I also replaced both my fuel tank skins twice and my leading edge skins once. Its kind of like the price of admission. Unfortunately mistakes cost time and money but you learn from them and become a better builder. There are times when I have wanted to take a jackhammer to my project and then haul it out into the garage and back my suburban over it twelve times just to appease my anger...but I'm glad I didn't.:D
As many have said, that's why we start with the empennage, parts are cheaper.
Personally, I would't try and make it work, I would order the new parts and have at it. You will find that you will have some fun working on it since you know how to do it now.
Take a deep breath in, have a beer and start over. I've done that numerous times...it works.
Give me a call when you get back in town and we'll go over the wing kit.
 
Solved

Well, I thought that I would tell you all what I finally did.

I brought the empennage to my home in Minnesota and called out to the MN RV Builders Association for help. They set me up with Jim Fogarty, a builder just a mile away and he came over to look at it. He then suggested that I contact Tom Berge, a professional RV builder and transition flight trainer for an expert opinion.

I hired Tom to fly up from the Cities and visit. He spent about five hours with me and a friend demonstrating riveting and a whole **** of a lot of other good stuff. He showed me how to drill out the rivets on the angle without damage and suggested producing a new angle with a flange large enough to give me a sufficient edge distance. I ran the plan by Vans and they gave their approval.

It took me about four (!) hours to successfully drill out those rivets and remove the angle, but the holes are perfect with no damage to the spars at all. I am building the new angle today and with Tom's instructions for the dimensions, plan for creating a pattern and a good riveting demonstration (and practice), I should have this wrapped up soon and be on to the fuselage.

I can finally sleep and not dream of this disaster! Instead of abandoning the project (as I was tempted to do), I am excited about getting going on the next part of the build. I think that I have learned a lot. Thanks to you all.....and especially Tom.
 
Every one of us that has completed an airplane has had those same thoughts. Way to get the help you needed and keep your project going.
 
Not only did you do the right thing, but you have demonstrated integrity and you will therefore have a well built and SAFE airplane.

Well done.

Cheers,
Dan
 
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