Since I need to wait for my snips to arrive before finishing the joint strip, I decided to finish fitting the sub floors. I had previously bent these support angles at Tom Thompson's place, so I laid out a hole pattern and drilled starter holes to #40.

Since Tom's brake left these angles slightly curved, I decided to make little spacer angle to ensure their position above the floor skin was consistent. I want the top surface of the angle to be 1 1/16 inch above the surface of the floor.

Here's the spacer angle in action...just clamp it to a stiffener angle, drill a hole, move the angle down a bit and rinse and repeat.

I used the angle drill to drill all the holes to the stiffener. Later, I drilled them all up to #40 for the 1/8 pop rivets I'll use. If I had an alligator squeezer, I'd probably use solid rivets, but pop rivets will be OK.

After putting the sub floor back in position, I laid out and drilled through the panel into the top flange of the floor support angle. The spacing between holes is further here since these will be drilled up to #19 for a bunch of #8 screws and nutplates.

Oh, and this order came from McMaster-Carr. These are part number 9263K289 o-rings which will be substituted for the o-rings on the #8 screws holding my tank access panels on right now. I've gotta take those panels off anyway to cover the center rib hole on each tank. Apparently you're supposed to do that if you're using flop tubes. Sure wish Van's had told me that in the instructions or plans. Grrr.