Facing the inevitable

For most of thirty years a typical Mooney fuel tank does a great job.  Then the inevitable blue stain or distinctive smell of avgas appears.  You were hopeful that facing a leaking fuel tank would be for someone else, but no such luck.  So what’s next?  You think, “Maybe I can patch it and get along just fine?”   Or maybe you can’t?

With the passing years this scenario was becoming so common that fuel tanks were literally compromising the value of the entire Mooney fleet.  Someone or something had to make a difference. The introduction of a chemical developed to digest Polysulfide sealer offered a glimmer of hope.  “Weep No More” to the scene.  Nearly nine years and literally hundreds of fuel tanks later many Mooney owners can attest to the merits of the Weep No More tank repair process. 

Leaking Mooney fuel tanks are still a problem.  But thanks to Paul Beck, Willmar Air Service’s Weep No More tank specialist, there is a solution.  Paul can recall success with the first project. He can also vividly remember the difficulty with the second Mooney where a different or unapproved sealer had been applied. Chemical application did no more than soften the sealer making it literally impossible to scrape clean. We were well on our way into a learning curve that would last for years. 

Early difficulties in removing original sealer were the norm.  Leaks after repair and warranties were also way too common.  We were on to a good thing, but had much to learn.  Being exclusively in the Mooney sales and service business we knew tank repair was so important that quitting was not an option. 

I am pleased to report that the efforts of a chemical supplier, support of Willmar Air Service and Paul’s dedication have literally led to the end of a dramatic learning curve.  Years of experience have confirmed that an ultimate leak free tank requires proper preparation of the cleaned surface and use of the best grade and thickness of sealer.  In the end, nothing is more important than the experience of the technician applying new sealer.  It is not possible to be too careful or look too close.

Any fuel leak needs attention, but not all require a total clean and reseal.  The key is having the experience to know the difference.  Isolating leaks is a science of its own.  Leaks in covers and at typical stress points can be isolated and repaired.  Leaks caused by age and deterioration from the effects of time and empty tanks for months will require more effort.

Anyone willing to work on a Mooney fuel tank deserves credit.  However, consider the risks of trusting your tanks to anyone without experience. 

Originally published MAPA LOG, August, 2009