Riveting the side skins is challenging at the rear two bulkheads where access is constrained. Once a bucking bar is found which can get on the shop head at the correct angle it’s not too bad. But I had a helper (Tim) … I would not like to have done this section on my own.
Access much easier for the Tungsten Bucking Bar along the stiffeners. We used the squeezer for the longerons, and also for the rear bulkhead rear flange.
We decided to try the gun on the outside for the riveting rather than back-riveting. Once started, it all seemed to go pretty well so we pressed on. I fired the gun, with Tim on the bar. Lots of people advocate back riveting with the mushroom bucking bar outside, the thinking being to protect the skin I guess. I find that by positioning the gun mushroom set carefully, gently stabilising the set with finger & thumb, it’s safe & controllable. But never remove the gun pressure on the rivet until firing has finished! Sometimes this meant that Tim had to provide a back force (in addition to the gentle pressure on the bucking bar) for me to be able to keep pressure on the rivet. Hence a well trained helper is very valuable!
There were just a few rivets on the bulkhead tabs below the stiffener J shape which needed a different bucking bar.
Note the furry cloth under the bucking bar in case of droppages!
We followed the advice in the manual to rivet the flat sides before the curved sections. Having done the curves along the bulkheads we turned the fuselage on its side and completed the lower rivets.
A short video of the riveting. Note the deliberate mistake here … we forgot to protect the side skin with a barrier in case the bucking bar got dropped. Luckily we got away with it, Tim did a great job and didn’t drop it…..
Side Skins Riveted!
Next adventure is to install rudder cables and more wires.