Bob
Regarding cleaning, all traces of oil, paper and water has to be
removed. That is about all they said. Apparently these items can
'burn' in fluorine and cause damage. I am flushing the whole tank
first with dishwashing detergent and fabric softener. This reduces
static cling and allows the fine powdery plastic to be flushed out. I
got a surprising amount of particles come out even after I had
vacuumed everything inside. Then I plan on plugging the holes with
cork and shake the tank with a gallon of acetone, drain it, and then
repeat with isopolyl alcohol. Acetone removes oils and IPA dehydrates
all surfaces. That's my plan anyway.
Regarding timeline, apparently they don't always run the
automotive-level fluorination process, so it depends on when we
deliver the parts there, and what they have in their pipeline. But
they said it shouldn't be more than 1 or 2 weeks.
My plan is to drive my tank over there sometime this coming week. But
if you are interesting in joining, I am willing to wait.
On Sat, Nov 9, 2013 at 2:54 PM, Robert Borger <rlborger@mac.com> wrote:
>
> Andrew,
>
> Two questions:
>
> 1. What is the recommended cleaning procedure to ensure the tank isnt
> fried?
>
> 2. What is the timing on procedure?
>
> I have my new tank almost ready to install. Just a few more supports
> to make up and the tank will be ready to go back in.
>
> Blue skies & tailwinds,
> Bob Borger
> Europa XS Tri, Rotax 914, Airmaster C/S Prop.
> Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
> 3705 Lynchburg Dr.
> Corinth, TX 76208-5331
> Cel: 817-992-1117
> rlborger@mac.com
>
> On Nov 4, 2013, at 10:16 PM, Andrew Sarangan <asarangan@gmail.com> wrote:
>
> Looking through the email archives, there seem to be some
> misunderstanding on what the tank is made of. It is polyethylene (PE).
> It is definitely not PTFE (Teflon) or nylon as some had suggested. I
> don't know why polyethylene was chosen, but my guess is it is the
> rotomolding process itself. The majority of rotomolding is done with
> polyethylene so that may have been the most cost-effective choice.
>
> Weather it is LDPE (Low density polyethylene) or HDPE, neither one is
> great with gasoline. Assuming it is LDPE, the attached chart lists it
> as "Limited Compatibility" at 20C and "Not Satisfactory" at 60C.
> Granted, liquids don't heat up quickly, but over a full hot summer
> week, 40C may not be unrealistic. It would be interesting to examine
> if the tank failures have come mostly from warmer climates.
>
> There have also been discussions about inadequate support of the tank
> that could lead to tank failures. This is true, but polyethylene
> should only yield under stress, not crack. Cracking is more indicative
> of a brittle material. My tank has been sitting on the shelf for over
> 12 years and when I was drilling out the bosses this week, it felt
> waxy and ductile, not hard and brittle. So it is not the age of the
> tank that makes it brittle. It is the exposure to gasoline. All of
> this points to the importance of a good barrier coating, and probably
> even more important in hot climates.
>
> I was also told by Fluoroseal that automotive level coating is
> generally not done in Europe. Not knowing the level of coating is the
> main reason I am pursuing a second coating on my tank.
>
>
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