Time: 6.5 hrs
Starting to finish up the fuel tanks since they have been tested for leaks and seem to be OK. I’d like to do a good leak rate test on them, but the gauge I purchased (Dwyer DWGW-04a0 isn’t working as I had hoped. I may just build a manometer as Pascal L. has suggested and do the leak test that way. In any case I’m not able to find any leaks using soapy water and saw no noticeable movement of the needle on my gauge while testing for 48 hours, though my gauge isn’t super accurate so it may not reflect any small leak.
In any case I felt it OK to proceed with priming the tanks so I got that done today. I’m waiting on some hard plastic grommets to use on the fuel vents so I can’t completely finish them until those arrive. I also need to rivet in the rib and short channel pieces and install the rivnuts.
Primer came out OK. I didn’t prime the rib because it’s already alodined so should be OK to leave unprimed. Once this dries up I’ll install the rib and channel pieces, plus the rivnuts.
I’m hoping to get the tanks installed by mid next week.
UPDATE 5/5/2020: Happy Cinco de Mayo!
I spent around 6 hours today getting the fuel tanks ready to mount on the wings. I installed the fuel vents, the remaining rib and channel pieces, rivnuts and also filled the rivets. The remaining rib didn’t fit so well, I kind of figured it would be an issue when I did the test fit. I ended up using my fluting pliers to get the holes to better line up, but still took some time to install.
I made a manometer for testing for leaks in the fuel tanks. It’s pretty accurate, but it does fluctuate with temperature quite a bit. Since the tanks are in the house and the temperature doesn’t fluctuate that much I just recorded various readings along with the temperature eons the gauge itself. After about 2 days of checking the markings against the current temperatures and finding that they were no different than the markings I had previously made then I could assume that the tank wasn’t leaking. Not very scientific but I think it’s better than the balloon test. I did also check all the rivets and fittings with soapy water.
Had to do some fluting on the rib to get the holes to line up.
For the fuel vents I ended up using a rigid plastic bushing rather that a rubber grommet. The grommets seem to dry out and fall apart so I thought the plastic might hold up better. I ended up upping the hole to 3/8″ and used some black RTV to seal it up and make sure the bushing didn’t move.
The fuel tanks are ready too go. Hopefully tomorrow I can bolt them in and then rivet them to the wings.