Those support pads that are "called for" are indeed "extra" as they were
not in the original design and were put in as an afterthought when problems
started coming about. The tank I have is one of the later versions as the
replacement I have is exactly the same.
Yes is does get hot here, however this has happened to others and it
seems issues point to the fact that this material and the mounting design
don't lend themselves to having the tank being emptied allowing it to dry
out and have the material migrate. The SOP with aircraft is to refuel
them before you put them away so this We could do a scientific experiment
and have every one drain their tank and let them sit for six to 10 weeks
and find out what the failure rate is. The issue is that this is an issue
and as I have noted another manufacturer has issued a warning about this
and now this should be formally documented as a characteristic of the
aircraft.
I did think of possibly molding a unit up from another material as kevlar
or graphite however another individual mentioned that it would have to be
bolted or otherwise mounted securely mounted in other than bonding.
However I hate to act as a guinea pig on something that is not in
widespread use. If I changed the mounting routine to something other than
bonding, the polyethelyne tank would probably be more than satisfactory and
that may be exactly what I do if the cost and logistics of making an
aluminum tank become too onerous. I don't believe an aluminum tank would be
bonded in either. I was sent a photo of an aluminum tank. I would very
much like to know how it was installed and what kind of service it is
giving if you are out there listeninng?
Thanks,
Steve Hagar
A143
Mesa AZ
> [Original Message]
> From: Fred Klein <fklein@orcasonline.com>
> To: <europa-list@matronics.com>
> Date: 12/30/2007 2:11:22 PM
> Subject: Re: Europa-List: Europaprecision?
>
>
> On Sunday, Dec 30, 2007, at 11:33 US/Pacific, Steve Hagar wrote:
>
> > I have tore into the top of the cockpit seatback to get at
> > the gas tank to pull it out because of the crack. Once the top was off
> > what
> > was present was slightly disturbing. We have our extra support pads
> > to
> > keep the tank from pooching into our spar cavity and interfering with
> > the
> > aileron belcrank rod. Every interior surface looks like that. The
> > top of
> > the tank is vavy from expansion and the back surface exhibits the same
> > condition. In all cases flat surfaces of the tank are stressed and
> > buckled
> > because of the expansion. You just don't see it unless you take the
> > lid
> > off.
>
> Steve,
>
> Thanks for sharing your frustrations w/ your fuel tank and passing on
> your thoughts on the issue of cracking....sobering thoughts and pixs
> indeed. A couple of questions:
>
> - When you say "extra support pads", do you mean that you installed
> some pads in addition to those called for?...If so, can you describe
> them?
>
> - At some point, I seem to recall that the supplied tanks were changed
> in some way to eliminate or reduce expansion. When did you purchase
> your original tank? Do you know if you have one of the earlier or later
> versions of the tank?
>
> - Do you attribute your tank's failure (in part) to any extreme
> temperature conditions which it may have been exposed to in your part
> of the world?
>
> To Anyone: Would you be willing to share any protocols you follow which
> you believe will guard against tank shrinkage and stress cracking?
>
> > I made note to a motorhead friend of mine at work that my airplane had
> > gotten a crack in its gas tank. He knows nothing of Europas or of
> > homebuilt aircraft. He asked me if I had a rotomolded polyethelyne
> > tank.
> > I said yes. He asked me if I left the tank dry for awhile. Yes
> > again. He
> > noted to me that there is a kit car company out there that makes
> > custom
> > tanks as these for cars. The company specifically states that if you
> > mount
> > the tank by fiberglassing it in and let it dry out. It will crack and
> > they
> > assume no responsibility. You are supposed to buy their mounting kit
> > and
> > strap it in.
>
> I got to confess that I questioned (to myself) the implications of
> fibreglassing in a tank which is subject to expansion, but blithely
> went ahead and installed it per plans, ignoring that little voice
> saying, "Hey...this can't be good, there's got to be a better way!"
>
> As for my previous post about my opinion of the high degree of
> precision built into the kit, I made that as an architect and
> homebuilder, not as a machinist, so the world of tight tolerances is
> one in which I've had virtually no direct experience. I do marvel at
> some of the various hardware assemblies and know that if left to my own
> devices for fabrication the results would not be
> satisfactory...sometimes the designs seem a bit too clever but that's a
> story for another time.
>
> > Also I also have a pair of reamers available 16 and 16.5 mm, one for
> > the
> > rough cut and one for the fine cut. I have cut them short and
> > machined a
> > hex on each end. That way you don't have to pull the endine way out
> > and
> > you can put a ratchet on the end to run them home.
>
> That sounds excellent...thanks for your offer to make them available to
> others!
>
> Regards and good luck w/ getting your plane back in the air soon,
>
> Fred
>
>
> --
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