Hooray!

Leak at the BNC connector for the resistance fuel gauge. Popped off the access panel on the inboard rib (it was held on with aviation gasket [...]]]> Yes, a hole appeared in the baffle…I coated the inside seams of the outboard rib with proseal. Re-riveted the baffle (it was being held together with clecos) and balloon tested…

Leak at the BNC connector for the resistance fuel gauge. Popped off the access panel on the inboard rib (it was held on with aviation gasket sealant) and smeared the backside of the BNC connector.

Finally, sealed up the tank with the allen screws Id bought from Grainger, and let the proseal set.

Testing today or tomorrow…

After drilling out the 250-300 rivets that held the baffle to the tank skins, I realized that drilling out the pop rivets that hold the z-brackets to the aft [...]]]> I found a leak in the seam of the outboard rib and leading edge. My poor balloon held air for a few moments before deflating to empty.

After drilling out the 250-300 rivets that held the baffle to the tank skins, I realized that drilling out the pop rivets that hold the z-brackets to the aft rib flanges would be a pain in the a$$. So after a little thought, I decided not to continue to remove the rear baffle.

So I gave in… I cut a rounded-rectangular hole in the baffle at the outboard end, to re-proseal the leading edge at the end rib seam, where the leak is.

I filed and scotchbrited the hole and a matching cover I made, the glopped a bunch of proseal along the inner seam. Unfortunately, there’s no way of knowing if I plugged the leak until the tank is sealed up again, so I’ll add a dollop of proseal to the rear corners of the outboard end of the baffle, just in case. Then we’ll seal it up and retest!

It looks like I’ll try to go in through the filler hole with a few toothbrushes full of proseal. Unfortunately, I need to recruit a small-handed individual since mine are far too fat!

All the leaking I could detect was through the fuel cap, but as long as that wasn’t sealed, there was no way to determine whether other pathways were still open.

I finally figured out how to seal up the filler cap (used transparent [...]]]> Well, at least I *think* there are no leaks in the left tank.

All the leaking I could detect was through the fuel cap, but as long as that wasn’t sealed, there was no way to determine whether other pathways were still open.

I finally figured out how to seal up the filler cap (used transparent 2″ wide shipping tape, because it had much better adhesion that duct tape, and any air pathways and/or pockets were easier to see through the transparent tape).

After 3 hours, the balloon is still inflated! I’ll check back in the AM to see if it’s still holding.

UPDATE: 12 hours, balloon still big!

You can see the clear package tape on the tank skin…the folds and bumps are on the top layer (there are at least three layers of tape covering maybe 12 sq in of surface area above the cap).

Right leading edge ready for riveting.

My dimple table hasn’t been used in many many months, so it needed a little [...]]]> While waiting for the new cork gaskets and K1000-3 platenuts, I moved the tanks off my worktable and replaced them with the leading edges. Since they’re built off-wing, I can work on them. They’ve been match-drilled and deburred, next comes dimpling.

My dimple table hasn’t been used in many many months, so it needed a little cleaning. I’ll (hopefully) dimple both leading edge skins tomorrow morning, and peel off the plastic along the rivet holes.

After patching the leak in the inboard end of the tank, I was sure that my balloon would hold air. And it did…

…for a couple of hours. I left it inflated with no obvious signs of trouble after watching for 30 minutes or so. When I returned about two hours later, the balloon [...]]]> Well, that stinks.

After patching the leak in the inboard end of the tank, I was sure that my balloon would hold air. And it did…

…for a couple of hours. I left it inflated with no obvious signs of trouble after watching for 30 minutes or so. When I returned about two hours later, the balloon was a sad sack of red plastic, hanging limply off the vent tube.

After airing up the balloon again, I sprayed with detergent to no avail. Today I picked up a mechanics stethoscope from Harbor Freight in an effort to localize any hissing. On Tuesday or Wed I should be getting some stainless steel cap allen-head screws to use on the access panel so I won’t keep stripping the phillips-head screws, as well as some Permatex 80017 Aviation Form-A-Gasket #3 Sealant. Then I’ll set a few hours aside and really go at it. Hopefully I won’t have quite as much trouble with the other tank!

I spent a few hours after that cleaning out the hangar and generally organizing all the stuff. It’s been a few years, and the place really needed a good cleaning! There’s probably another 2-3 hours yet to do, but that can wait til later.

3 cork gaskets @$4.70 ea. (Van’s) …I sacrificed one Sunday + a couple extra just in case 24 stainless steel replacements for AN515-R8R, socket cap McMaster 92949A194 $5.55/100 Grainger 2WB73 $7.66/100

3 K1000-3 platenuts (Van’s) $.50 ea …seem to be missing one for the z-bracket on a [...]]]> Need to get stuff I’ve screwed up over the past couple weeks:

3 cork gaskets @$4.70 ea. (Van’s) …I sacrificed one Sunday + a couple extra just in case
24 stainless steel replacements for AN515-R8R, socket cap
McMaster 92949A194 $5.55/100
Grainger 2WB73 $7.66/100

3 K1000-3 platenuts (Van’s) $.50 ea …seem to be missing one for the z-bracket on a tank
3 AN3-4A bolt (Van’s) $.11 ea …also missing a bolt