Saturday, December 5, 2015

Finished Tank and Access Platenuts - 10 hours



Huge day in the garage! I started to prime the HS#2 front spar parts as well as some wing platenuts.
Then I set to work on riveting on the platenuts. The majority of the platenuts go on very easy. however, the angled platenuts are a tad more challenging.  Installation of cleco's also presents a challenge with using my squeezer. I found if I used then from the inside out allowed much better access for the squeezer.

 
Setting the rivet closest to the spar web is a bit difficult as the factory installed rivets in that area limit clear access with the squeezer. I ended up having to drill about 5 or so rivets that stuck up just a bit too much. To my delight drilling out the rivets went extremely well and I re-set them.  
Before attaching the #6 platenuts for the access plates, I began to wonder if I needed to drill out the holes for the #6 screws (as they won't fit thru the holes as-is). So back to reading the instructions/forums/buildlogs. So I determined that I keep going and don't drill just yet. That lead me to wonder about countersinking the #6 holes. Everything I read is <0.3175", But nothing is definitive. So I grabbed the access plate drilled, deburred, dimpled it to #6 and then grabbed a piece of scrap and set out figuring out the proper countersink depth. After much back and forth I settled on a countersink diameter of 0.300" This allows the #6 screw just below the surface with a slight halo around it, which seems to be inline with the description on the forums. And it is also just clear of the edge of the flange. I also reasoned that at that depth it helps to ensure that I don't countersink too deep and ruin the spars and it provides a decent fit of the plate.

 
Of course though....I will get a second opinion on this before I go too much further.

Update, I ran this by my friend Mike who is an Aircraft mechanic by trade, and He was please with what he saw. It's nice to have knowledgeable people around to bounce things off of.  

Once I felt confident that I had the access plate platenuts figured out, I completed riveting them on the spar.Once the Left spar was done, I then continued on to the right spar. By midnight I was done!