Spar riveting technic ?

[Concorde]

I know the Sonex way of hammer and the bolt technic , but looks like it's a lot of hammering and hard work especially doing it solo in a nice 95 degree work shop for someone who is no longer 25.
So what is the easier option, using the C clamp squeezer tool or the rivet gun and which is more fool proof ?
Also for the dimpling the spar skin did you drill the holes to 5/32 or smaller?

By talking to a RV friend ,it sounded like that they drill all the holes to the final size and saying the rivet will fill the space after it's set.
Thanks
Ben

[Bryan Cotton]

Ben,
Drilling holes undersize for dimpling is a 120 degree pop rivet thing. For 100 degree AN rivets there is no need. Your RV friend is right.

I bought a prebuilt spar but have set countless solid rivets. The rivet gun works fine but for -5's I would want at least a 4X gun if not a 5X. A pneumatic squeezer is by far the easiest and coolest way to do it but you are looking at some bucks for one big and powerful enough. I assume you don't mean a real C clamp. That won't work.

Rivets and scrap are cheap. Rivet some scrap using each of the methods and decide for yourself. Good to practice a bit too.

[kevinh]

I built an RV so had lots of solid rivet practice. My 3X gun worked fine IMO (if I remember I used about 60psi - test and practice on scrap to get your technique down). You'll wanna get the Sonex bucking bar because it fits nicely. There are still some rivets that you'll need to use the barbaric hammer method for (at least I did) - because I couldn't fit a rivet set everywhere.

A standard RV cframe won't be able to get into most of the rivets, so I didn't bother.

[wlarson861]

I used an Avery c-frame and a 3x gun.If I was to do it again I would use the same method but would try to go to 4x or 5x gun. with the c frame on the basement floor I back riveted both the standard and flush rivets. It is time consuming, with the larger gun I think they would set much faster. I had a few work harden before they set and had to drill them out and try again.

[rizzz]

I know the Sonex way of hammer and the bolt technic , but looks like it's a lot of hammering and hard work especially doing it solo in a nice 95 degree work shop for someone who is no longer 25.

I understand your concern, it's hard work no question about it. If you have propper solid rivetting skills & tools, by all means do that!

However, for those contemplating the Sonex Hammer & Bolt method, it's not as bad as some would make it out to be.
Looking back at my log, I spent just over 10 hours on the first spar and just over 5 on the second one (I must have gotten better at it along the way, or less critical :D), took me about 2 weeks in total to get them done.
I remember far worse tasks than this one building my airplane (cowling, canopy, wing rigging, ...)

[Bryan Cotton]

I bought a 4X on the advice of an RV4 builder friend. He said you could dial it down for the -3s and it had enough beef for the -5s. All true. Since then I bought a 5X off ebay for cheap and I love it for the big rivets. Bought some Schweizer 3x guns at auction and I love them for the little rivets. I think I have become a rivet gun snob.

[planeolbob]

Hi Everyone,
I can only say that I started with the gun but went to the hammer method quickly. In fact, while I was building my spar I had a party at the house and much to my wife's regret I invited our guest down to the basement to "Help Me Build an Airplane". These were men and women who had never even seen a rivet. Here is some photos of the method I used:

https://www.flickr.com/photos/planeolbo ... 0661865507

click on each picture and read the comments. Each guest did 3 rivets. The first rivet needed 4 hits to mushroom the shop head perfect. The second and third needed 3 to make perfect. After about 10 I only needed 2 hits.

Bob

[gcm52]

I got a big rivet squeezer on ebay for $300. It works great and requires less skill than a rivet gun. I used it to rivet the spar for a zenith 701. It then sat in the basement for 8 years. Before I was going to use it to rivet the spar for my Onex, I sent it off the Yard store for a inspection and rebuild. They said it was in perfect shape on nothing was needed. Three cheers for the Yard store. I then used it on the ONex spars. I could probably sell it on Ebay for $300 right now, but I am too attached to it to ever sell it.

[rk2436]

The Sonex spar cap is different than the Onex. You won't be able to use a squeezer on the Sonex. It would be nice if Sonex had the same tool for builders to use that the Panther uses. Back riveting with a 3x worked for me but there still are a few you have to Fred Flintstone.

[Direct C51]

https://sonex528nm.files.wordpress.com/2015/09/8.jpg

I highly recommend this technique if you can get ahold of a C frame riveter. The one I used was specifically modified for Sonex spars.