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A riveting Question

Mike K

Member
Getting ready to rivet the forward flange of my wing ribs to the main spare. Does it matter what side the rivet head is on? Spar side for the head seems to me would be easier to drive but I have been told you should have the bucking bar on the side with thicker material, being the spar side. Any advice would be appreciated.
 
true

If you have a choice and access is not as issue then yes the bucked end (bucking bar) side should go on the thicker material - this helps with distortion issues.

However the better consideration is getting the rivet gun on square. For the spar put the dome head on the spar and buck the rib side. This prevents using an offset rivet set which doesn't work as well.
 
Rivet direction

Getting ready to rivet the forward flange of my wing ribs to the main spare. Does it matter what side the rivet head is on? Spar side for the head seems to me would be easier to drive but I have been told you should have the bucking bar on the side with thicker material, being the spar side. Any advice would be appreciated.

Generally the shop head (or the bucking bar as you describe) should go on the thicker material. I this case the spar. If you place the shop head on the rib side you will see the rib flanges curl a bit from the expansion of the shop head. If you place the ribs on the main spar and temporarily leave off the rear spar the ribs can be gently displaced to one side allowing better access for the rivet gun.

You won't be able to use this technique for the rear spar as the ribs cannot be displaced for gun access. For situations like this I like a rivet set with a single offset. Tape a piece of wood against the rib web allowing the single offset rivet set to bump up against the wood. This is probably cheating a bit but a shim between the rib and the rivet set will prevent the set from walking on the factory head. A piece of masking tape on the rivet set will also help prevent marring.

I see you are in Hays. The Yard Store in Wichita is a good place to get a variety of rivet sets. For us folks in the midwest, UPS ground usually provides delivery the next day.
 
Thanks for the feed back, tips, and vocab lesson (shop head). I think I will drive a few practice rivets with my offset rivet set tomorrow then decide.

Mike
 
So it is OK to have the rivet had on the spar and have the bucking bar on the inside where the ribs are?

I ask this because I riveted all the ribs with the heads on the rib side, except for the 1010 rib. This one has the torque tube assembly so it is impossible to get the rivet gun in to buck the rivets, so the heads have to go on the spar side and not the rib flange side.

I was told by an EAA tech guy that if button head is on the thicker side that the diameter of the rivet after bucking should be 1.33x diameter and not 1.5 diameter.

Thoughts?
 
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