Tonight put some nice closure on the first part of the wing construction - finishing up the front and rear spars. First I polished off the front spars by riveting the tie down bracket together and bolting it to the front spar. I also put the bellcrank bolts on, knowing that they will have to come off when I put the bellcrank on. That's fine by me because at least I have all of the parts where I know they are. No real tricks to this, except I did have some slight alignment problems with the AN3 bolts. I just took the #12 bit and reamed out the holes a little and everything went together nicely.
Next was onto riveting together the rear spar. I did both of them together so I could set the squeezer to one rivet size and bang it out on both. I marked the holes I wasn't suppose to rivet with electrical tape.
One wierd thing was the primer didn't stick to a small part of the tip of one of the rear spars. I quickly analyzed it by scratching around and determined that it was only a local problem. I sanded it down, cleaned it with acetone and sprayed it with Sherwin Williams GBP-988. I don't know if that part was contaminated or if there was some contamination in the gun.
Tie down brackets riveted together.
Bellcrank brackets bolted onto the spar. UPDATE: Don't do attach these brackets yet - You have to take at least the top one off when you install the bellcrank. Plus, they will interfere with bucking the rivets behind them on the spar flange. It might not be a bad idea to waste one AN3-12A bolt to make sure the nutplates aren't stripped or misaligned, because it would be a real pain to have a stripped one and not realize it until the wing is in the cradle and the fuel tank it permanently installed. Hold off on putting these puppies on until the bottom skin is on. You will save a couple of AN3-12A bolts.
And the other side.
This is the wierd spot on the tip of the spar that the primer didn't stick to. Wierd....
Looks good now with GBP988
The root marked off....
...And the center marked off....
And the tip marked off.....One word for marking all of this crap off - screw that. The other spar I did just by reading the rivet layout. WAY quicker.
Finished rear spar.
All of the spars finished....waiting to be put together with ribs...
Last Modified: September 28, 2019