Thanks for all the ideas. The problem, as I understand now, is the
attachment mechanism, and not necessarily the swelling. If the tank
can be supported without bonding its surfaces, then it should be able
to relieve the stresses as it expands and contracts. That's what I am
gathering from these discussions.
More puzzling is, it seems there is no agreement on what the tank is
made of. Just in the last few emails, I've heard Polypropylene, HDPE,
LDPE all mentioned, and Yerly's article says it is PTFE. I am somewhat
familiar with different polymers, and these are all very different
materials. I doubt it is PTFE because it is super expensive and
nothing will stick to it. I know a chemical test to identify different
polymers, but I would need a small chunk of the material. If I ever
figure that out, I will make sure to post my results here.
On Sun, Jul 7, 2013 at 3:43 AM, Duncan & Ami <ami-mcfadyean@talktalk.net> wrote:
>
> The tanks are low density polyethylene, I understand. And they shrink back
> over time when left empty (but not in my experience by as much as the
> initial expansion). Fluoridated tanks may be different.
> The Kitfox company understood this problem in 1990.
>
> DMcF
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of andrew cullum
> Sent: 06 July 2013 22:53
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Fuel tank question
>
>
> --> <asc23111964@hotmail.co.uk>
>
> Hi Andrew,
> One question,have you filled your fuel tank with a mix of fuels you are
> going to
> use,and contained the tank with a sturdy wooden frame,and left it for at
> least 6 weeks? The poly-propylene apparently expands by about 10 per cent
> With the addition of fuel,this was in the old manual,but doesn't appear to
> be in the new one. Could it be that tanks that have cracked haven't had this
> pre-soaking? As for the cork at the bottom of the fuselage,sounds like a
> good idea,I'm sure that Bud can help you out. Best Regards Andy Cullum.
>
>
> Sent from my iPhone
>
> On 6 Jul 2013, at 20:47, "Andrew Sarangan" <asarangan@gmail.com> wrote:
>
>> --> <asarangan@gmail.com>
>>
>> After a one year pause, I am getting back into building. I am near the
>> stage of bonding the fuel tank into the CM. I read a lot of
>> discussions about tank swellings and cracking, so I am a bit
>> concerned.
>>
>> Doing a google search, I came across a fuel tank mod document written
>> by Bud Yerly where he suggests using a cork pad in the fuselage to
>> support the tank. The details are a bit unclear to me, so I would like
>> solicit opinions from anyone who can give me some insights.
>>
>> Thanks in advance!!
>>
>>
>>
>>
>
>
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