DakotaHawk
Well Known Member
After filling my fuel tanks for the first time a few days ago to calibrate my fuel level senders, my tanks have been sitting with about 18 gallons of fuel in each side. Yesterday afternoon, while crawling under the right wing to make an adjustment to the aileron linkage, I saw this...
Uh Oh!!! So I looked a little closer, and found that there were several rivets that had bulging paint blisters. Probably more weeping rivets under the paint!
Well, after talking to a couple of friends and searching out VAF forums, I decided that I couldn't allow the situation to stand. After de-fueling and removing the fuel tank (about 45 minutes), I took the tank home and marked the offending rivets - just in case I needed future reference.
Looking at the plans, I reminded myself that I would not be able to reach through any lightening holes to pro-seal the rivets, since the baffles/ribs don't have any lightening holes!
Looks like I'm going to have to cut an access hole in each bay to get some pro-seal in there. I measured my hand and determined that I could reach through a 3 1/2" access hole, so out came the fly-cutter.
I had to cut into three bays. Mix up a batch of pro-seal - no reason to scrimp on this stuff - I'm only adding a couple of ounces and I REALLY don't ever want to open this up again. I used a round tip applicator to force about a 3/8" fillet of pro-seal along the joint. The rivets are on the exterior of the tank, and there's no fixing the rivets after the fact. So the joint is gooped up. I used a little MEK on my gloved finger to really force the pro-seal into the joint and smooth it out.
Next step is to make some 4" cover plates and install nutplates in the fuel tank.
After lots of vacuuming and cleaning pro-seal, it's almost ready to pro-seal the cover plates and screw them in place.
I'll give the pro-seal a couple of days to completely cure, then fill the tank up with av-gas while it's still on the bench. I'll let it sit for a couple of days to see if there's any more leakage before bolting it back onto the wing.
In the meantime, first engine start is scheduled for tomorrow and I don't see any reason to postpone that event!
Uh Oh!!! So I looked a little closer, and found that there were several rivets that had bulging paint blisters. Probably more weeping rivets under the paint!
Well, after talking to a couple of friends and searching out VAF forums, I decided that I couldn't allow the situation to stand. After de-fueling and removing the fuel tank (about 45 minutes), I took the tank home and marked the offending rivets - just in case I needed future reference.
Looking at the plans, I reminded myself that I would not be able to reach through any lightening holes to pro-seal the rivets, since the baffles/ribs don't have any lightening holes!
Looks like I'm going to have to cut an access hole in each bay to get some pro-seal in there. I measured my hand and determined that I could reach through a 3 1/2" access hole, so out came the fly-cutter.
I had to cut into three bays. Mix up a batch of pro-seal - no reason to scrimp on this stuff - I'm only adding a couple of ounces and I REALLY don't ever want to open this up again. I used a round tip applicator to force about a 3/8" fillet of pro-seal along the joint. The rivets are on the exterior of the tank, and there's no fixing the rivets after the fact. So the joint is gooped up. I used a little MEK on my gloved finger to really force the pro-seal into the joint and smooth it out.
Next step is to make some 4" cover plates and install nutplates in the fuel tank.
After lots of vacuuming and cleaning pro-seal, it's almost ready to pro-seal the cover plates and screw them in place.
I'll give the pro-seal a couple of days to completely cure, then fill the tank up with av-gas while it's still on the bench. I'll let it sit for a couple of days to see if there's any more leakage before bolting it back onto the wing.
In the meantime, first engine start is scheduled for tomorrow and I don't see any reason to postpone that event!