Thorp Air Command - T18.net

I know what the technique is. I'm just wondering what the pros & cons are to this technique. And is back riveting something that is common with building a Thorp?. I know I have read that RV builders use this a lot.

It appears they make flat steel bucking plates and dedicated rivet set specifically for back riveting.

I can see how back riveting would eliminate or minimize the possibility of leaving a "smiley" on the surface. No one plans to leave a smiley. And I'm sure most builders are diligent and careful. Yet I have to admit, I've seen several planes at Oshkosh with a few smiley's. But maybe that just adds character and a story to the plane!!!

THe stiffeners and a few other parts can be done "back buck". For the most parts straight on rivet gun and bucking bar for the rest. My back buck is a 12" square 3/8 thick stainless
I have a flush set that is 1 3/4" diameter and its hard to leave a smilley face that the small ones leave.

Back riveting (zero chance of Mr. Smiley) is easy to do and I think you have more control of the gun as apposed to holding the gun and bucking bar . My plate is about 6" wide x about 24" long . Back rivet when you can , use a gun and bucking bar when you can't and use CM rivets when your arms aren't long enough and a "helper" is not available . "Hit um with your best shot !"

RB