Installed new 3” wide tape over fuel cap and reinforced it with more tape. Tested for leaks again using the manometer with a 27” difference in water height in the tube per Vans instructions. Water actually rose in the open end of tube indicating a drop in air pressure, which according to my weather app, it dropped all day. Feeling pretty good that I don't have any leaks in the right tank. Sanded down the wingtip to remove the “bad” West systems 410 fairing filler that could blister the paint on a hot day per the expert at the OSH RV fiberglass forum. Reapplied 407 fairing filler that supposedly will not cause blisters.