I used the 10 oz soft tank in mine and left the tank shelf out. Glued foam to the top and bottom of the tank compartment and the tank slides between the foam. I used fiberglass reinforced tape and made two pull tabs attached to the tank. I did remove some material from the F2 to get the tank in but have seen no problems yet. You can pull the tank out over top of the joiner tube with the soft tank. I also run the ST G51 in this plane.