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Permalink Reply by Phill Barnes on December 27, 2011 at 11:06pm

Hi Scott

It really depends where the location of these holes are. If in a non structural position like the wing tip, then yes put some rivets in them and do the same on the other wing if that is where it is to stop people asking questions about an irregularity. Otherwise, dimple the holes and put CS rivets in them and maybe some filler if you want to. If it is a structural part, then you should make a triangular doubler to go over top from the same thickness material and pick up the proper holes and space more around the outside using the proper edge distance and in doing so just covering up the stray holes which do not look like they meet edge distance requirements. Also the top rivet on the bottom pic has been drilled through the side of another hole. You will need to install a doubler in there to and pickup a couple of other rivets. The far right rivet on the top pic is also not good enough. Rivets need to pulled square and showing no gap under them. If you use an air riveter, slow the riveter right down and as it sets the rivet, it will pull the gun square particulary when riveting thick materials. Seeing as you can see imperfections on the outside, I would be getting a snake camera and checking all internal hidden joints.

 

I am not trying to knock your Grandfathers workmanship, but when it comes to aircraft big or small, there are tollerances and standards that must be adhered to. 

 

Good luck

Phill

Attachments:

• zenair construction standards draft 1-07.pdf, 773 KB

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Permalink Reply by John Austin on December 29, 2011 at 8:55am

Phil,

How do you slow a pneumatic riveter down? Reduce the line pressure?

John

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Permalink Reply by Phill Barnes on December 29, 2011 at 3:50pm

Hi John

I keep my line pressure at around 100 psi. I have a small regulator tap fitted at the bottom of my riveter that I use to slow it down similar to the pic below that I googled. My regulator cam with my riveter from Zenith but you can pick them up at just about any tool shop. This unit is more of a flow regulator than a pressure regulator. When I was riveting my spar line through the new thick angle on my Zodiac wings, I found that if you pop the rivets fast, the gun wouldn't have time to square the gun up and the thick material made the recoil so hard and fast that the gun would jump and put a smiley in the rivet head. Once I slowed it right down as slow as it would go, the gun pulled itself square instantly and then the rivet popped and the recoil was so slow and hard it gave me the split second and the height from the surface that I needed to pull up to prevent the gun from damaging the wing. With thin materials, I found that the speed didn't make much difference as it appears that the pull of the gun and rivet pulls the material into allignment monentarilly instead.

It might seem like it is a slow process but it still takes the same time to load a rivet and drop the stem out after. The only difference is that the pop process goes from 1/2 a second to 1 second instead.

 

I hope that I explained my process well enough so that you can picture it in your head but the best way is to grab some thick and thin scaps and give it a go for yourself.

 

Phill

 

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Permalink Reply by Steven Ward on December 28, 2011 at 12:13am

Walt, I like your since of humor! I would probally be one who copied it just in case!

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