I found it much easier to proseal the tanks with the jig tilted towards me. I came up with this simple way of positioning the jig using a couple of scrap pieces of 2 x 6 and two quik-grip clamps.
I saw Smitty's set-up, but your's seems less labor intensive. (I'm trying to focus my efforts on the plane and not the jigs as much as possible.) I do believe I'm going with yours.
Your jig idea is neat. I'm just curious why you decided to not install the inboard access panel. Not that there's a problem with your method...just curious about your rationale.
The reason I didn't install an access panel is that I didn't use a fuel pick-up tube, so I decided to mount the fuel level sender directly to the end rib and eliminate a large area of potential leaks. I think this provides as much access as you are likely to need.
The big difference here is the fuel pick-up I am using, which is from an RV-10. The fuel pick-up fitting is a brass hex pipe bushing with an extended tubular screen that projects into the tank. This pick-up is screwed into the flange at the lower rear corner of the end rib. This setup gives you the advantage of a pickup with no movable parts inside the tank (no anti-rotation bracket or safety wire required) as well as a pick-up screen that is removable for cleaning.
My technical counselor (Bob Barrows of Bearhawk fame) was impressed with this setup, and said that is how he has configured his fuel pick-ups. He felt this set-up was significantly better than the standard fuel pick-up tube (and all of its potential problems).
