Fiberglass Tank Grief

[mhcrowder]

Our newly completed Highlander came with Fiberglass tanks. After 25 hours on the engine, we've noticed a fuel "seep" at the left fuel tank outlet to the header tank. We've tried various Permatex and Loctite products to try and stop the seep, but so far we haven't been successful. Not to mention that each time we removed the fuel strainer and put it back it with new thread sealant, it would go further into the tank as the brass strainer cut into the fiberglass. We've finally had enough and the wing has come off the airplane and we are going to install a permanent metal fitting into the wing. We're hoping to use Hysol E120-HP structural adhesive epoxy that claims Ethanol resistance. Standard Hysol 9460 used on the kits only claims gasoline resistance. We don't plan to use Ethanol fuel, but I'd rather play it safe.

We'd much rather be flying right now, but this fuel issue has got to be fixed.

--
Michael Crowder
Ed Bodette
Highlander N371EM

[danerazz]

I was afraid of this on mine, so drilled and tapped larger holes, bought brass reducer bushings, coated the threads with regular fiberglass epoxy (West System), threaded them into the bigger holes with an epoxy-flox mixture fillet around the hex. Haven’t leaked a drop.

Sorry to hear it is after you finished, I did it as part of my list of “good ideas” before the wings went on or had fuel in them, and it is one of only a few that I still think were “good ideas.”

[mhcrowder]

We're in the process of putting everything back together now. Getting pretty good at pulling the wings off the airplane now! We're going to wait until a rainy winter week to do the same on the other side. Luckily it isn't leaking. The hardest part was drilling the new hole. Had to create a drill guide out of some 1/8" steel plate. If we had used the existing hole it would have dropped the hole too low and we would have drilled and tapped into the bottom tank surface. We're really happy with the results.

[Tralika]

That's got to be frustrating. I've had no problems with the fiberglass tanks in my Highlander. I remember discussion about early Highlander fiberglass tanks with problems but don't remember when the factory corrected it. Some time prior to 2009 when my kit was produced. Hope your fix works.

[gme9261236]

The original tanks ruined our wings and had to be pulled. Lost 2 years of flying dealing with that stupid issue. New tanks have held up nice thankfully.

[scubarider2]

I was one of the first to have issues with the fiberglass tanks. There were not cured correctly and it basically ruined my expensive Rotax 912uls. Troy did try and fix it by having some things paid for having the engine worked on, but it was never the same after that.

[gme9261236]

I was one of the first to have issues with the fiberglass tanks. There were not cured correctly and it basically ruined my expensive Rotax 912uls. Troy did try and fix it by having some things paid for having the engine worked on, but it was never the same after that.

No idea how we escaped the engine issues. Was an absolute disaster, dripping through the wing and essentially soft as putty until the fabric outright failed.

[SheepdogRD]

I was one of the first to have issues with the fiberglass tanks. There were not cured correctly and it basically ruined my expensive Rotax 912uls. Troy did try and fix it by having some things paid for having the engine worked on, but it was never the same after that.

No idea how we escaped the engine issues. Was an absolute disaster, dripping through the wing and essentially soft as putty until the fabric outright failed.

I think the problem was mistakes made in the types of resins and hardeners used; they were not the materials that Just specified, but there was no way to tell that by appearance, so some of the bad tanks were installed by customers. There may have been more than one incorrect type of resin used, and thus varying results: at least one of the resins apparently failed in contact with fuel, and it caked up in the engine. That was probably the source of your problems, Dennis. Another resin failed in contact with fuel, but didn't attach itself to engine parts.

Just stopped using the fiberglass parts supplier that screwed things up, and started working with a local supplier. None of their tanks failed. Over a decade later, AeroSmith Composites is still producing parts for Just.

None of that information changes your experience. I'm sorry you went through all that grief and work, and that you've lost so much flying time.

[mhcrowder]

Wow! Our issue seems mild by comparison! Sorry you had such a problem. Our fix seems be be working. We've been checking our filters to and after 30 hours run time we've seen no debris in the filters.

==
Michael Crowder