Begin the horizontal stabilizer assembly process

While waiting for the primer to cure, I built the cradles for the eventual assembly of the horizontal stabilizer. Then started riveting the rear spar per the instructions. After so many days of prepping it’s nice to get back to riveting with the squeezer. I know there will be some challenging bucking to do, so I’m enjoying the relatively straight forward process of setting the dome-head 470 rivets in the easily accessible surfaces of the rear and front spars.

A consistent theme on this project has been that the things I’m very concerned with tend to be easier than I think and the things that I don’t think much about are more challenging. Case in point, fastening the hinge brackets to the rear spar with AN3-5A bolts with MS21042-3 lock nuts. A brief reading of the torque spec suggests that these should use 28 in-lbs and I tightened as such. First I was surprised how little torque 28 in-lbs is and can see that it would be very easy to blow past the torque wrench click. Secondly, I realized that I had goofed on the torque spec. I was reading some other blogs and one mentioned that they were torquing to 42 in-lbs based on the Van’s instructions. A more thorough reading helped me understand this. The instructions say you need to add the extra torque required to turn the locking nut on the bolt to the overall spec which in their experience is usually about 14 in-lbs more giving a total of 42 in-lbs. I love this project because I learn something new every time I’m working on it. it’s best when the learning happens before it’s too late.