Happy New Year!  The project has taken a back seat to other priorities over the last few weeks, but today I had the opportunity to fix a problem that has been bugging me for awhile.

Seems that when I drilled the lower firewall weldments to the large longerons that support them, I managed to mis-drill a couple of the holes so that they weren’t perpendicular to the longeron, making it impossible for a bolt and nut to seat correctly around the hole.

I guess I’m not the first person to make this mistake, since there were a couple of threads on Vans Air Force on how to fix this sort of problem.  The solution of choice is to fabricate some angled shims or washers that allow the bolt head and locknut to be fully supported.

Here’s the shim I fabricated for the forward hole, there’s another one just like it on the underside of the joint.  As you can see, the hole was pretty far off perpendicular.

The aft hole wasn’t so bad, I was able to grind a couple of AN960 washers to serve as shims.

Here are a couple of pictures of the end result. I’m not proud of the screwup in the first place, but the fix worked well and I’m happy with how it came out.

Now it’s back to riveting!