Thanks gentlemen, I appreciate the support.
I bought "pickled" hot rolled steel. This stuff literally had oil pouring off of it as I loaded it into the van. Hence the lack of rust! I just wiped it a bit before I started welding. I will clean it with Dawn before I paint it.
I am going to primer it then paint it flat black, rattle can style. From experience with my original Con-Ferr rack anything besides flat paint chips off. Being so high off the ground makes for a lot of sliding of materials along the rails to get it up top. Scratching up an expensive powder coat job would sting and chipping off a semi-gloss or gloss coat would start to look pretty bad after a few touch ups because it's so thick. I find that a quick sand and spot spray with flat blends in pretty good. I paint all of the wear surfaces in my FJ40 with flat black so I can easily touch them up (center console, toolboxes, etc.).
Tonight I finished welding the second ring. The next step is to drill the bungee cord holes in the porthole plates then weld in the strut channel on the bottom ring.
I want to stick as close to the Con-Ferr assembly method as possible. They welded their porthole plates straddling the tube butt welds. Obviously that helps secure the joint.
They also separate their porthole plates by 9".....or at least they did on the rack I have for my FJ40.
On my new rack, in order to straddle the butt joints with a porthole plate I need to have a 7.5" separation between the plates. Chalk that up to poor planning. I could have adjusted the lengths of the pipes to have 9" spacing if I had thought of it. I can't do anything about it now.
Since I like the equally spaced porthole look I'm sticking with 7.5" spacing on the sides of the rack. Not including the corners that makes 6 single porthole plates per side, then two more with the corners. I just need to decide whether or not I want one single porthole plate in the front and rear of the rack or two. One leaves a lot of airflow space while the other does not. I'm not sure I should be too concerned with airflow since I'm going to have 4 PIAA's across the front anyway, there will essentially be no airflow through the rack. This is why I need a fairing.
One single porthole in the center (my original Con-Ferr rack only has one in front):
Two portholes in the center:
The single porthole design leaves the possibility of the rails getting dented on either side of it. The double porthole virtually eliminates that possibility and gives the rack an overall indestructable look. I live in earthquake country...you never know when you might need to remove your rack and use it to cross a large fissure in the ground! I think I'm leaning towards the double porthole. I made 17 individual porthole plates, the rack will use 16 in this case (not including the corners).
Tomorrow I'm going to stop by Home Depot and pick up 4 10' sticks of electrical strut channel. I'm figuring I will use 25' but I'm not sure yet. I think the channel weighs about 1lb. per foot so the less I use the better. I'm not planning on spacing the channel according to the beam pattern in the vans roof. I want to be able to use this rack on other vehicles in the future so I'm just going to space them equally. I will add in additional supports to match up to the roof beams, something that's adjustable.
I might wait until next weekend to assemble the final product. At this stage I don't want to screw up. Welding after work puts me welding in the dark and in a hurry to finish before dinnertime.