tungsten bar OK for back riveting skins?

[IowaRV9Dreamer]

I'm (almost) ready to rivet on my top skins. I am planning to back rivet them, with a long offset back-rivet set in the gun. I bought the big, back-riveting bucking bar from Avery but it's awful heavy. It has a round face about 2-3 inches in diameter.

Has anyone tried using one of the little tungsten bars for back-riveting wing skins? I have a 2x1x1 bar from Stein which I have been using exclusively. Has anyone done this before? It sure would help out my 10 year old rivet assistant!

Thanks!

[JohnR]

Dave, I think it would work okay. We have abckriveted all of our skins with a tungsten bar but it is nade for backriveting. I think the other tungsten bars would work fine, hust need to be more precise in holding it. Here is what we use. (the bottom one is the tungsten we use for backriveting)

[rv9aviator]

I tried back riviting the wing skins and found it was easier to just use a mushroom head and the same bar in the above post. I don't have one dent in my skins and used a mushroom head with the rubber ring around the edge.

[cnpeters]

I used a large mushroom bar made for backriveting on the outside with a long offset backrivet set on the inside. On the mushroom bar, the edges are slightly rounded. With a dead flat bar, you need to be careful to not tilt it a little, or it will dent the skin. Personally, I ended up switching to a conventional swivel set/gun on the outside, and a tungsten bar on the inside. Comparing the two techniques, another builder and I felt the rivets were more flush with using the gun on the outside. Also, we never had to drill any out, whereas backriveting I did. Lastly, at 45 psi on a 3X gun and the tungsten bar, it took a 1 second zap to set the rivet, where backriveting took 3 seconds. On an RV-9 wing, it made difference!