I am not a chemist, but I am certain acetone is a dipolar solvent - it
works for polar as well as some nonpolar liquids. I use it for
removing oils, lubricants, glue and paint.
On Sat, Nov 9, 2013 at 8:34 PM, Rob Housman <rob@hyperion-ef.com> wrote:
>
> I suggest that you re-think your sequence. Perhaps you scheme will actually
> get the tank clean but since both acetone and isopropyl alcohol are polar
> solvents they won't do a thing to remove oils which are by definition
> non-polar. Water is another rather well known polar solvent and I'm certain
> that you realize that water alone won't remove the oils. A lighter
> non-polar solvent (such as paint thinner) will get the oils out and then the
> detergent (polar at one end of the molecule and non-polar at the other end)
> in water will get rid of the residue. Acetone will do a nice job of
> gathering up the water after getting rid of the oils. The fabric softener
> will probably adhere nicely to the tank's surface (that's how it works).
>
> In the spirit of the old adage about being better safe than sorry, I must
> point out that gasoline is also a non-polar solvent and some folks have been
> known to set themselves on fire using it as an oil removing solvent. I
> would not expect anyone on this list to try for a Darwin Award, so I
> probably did not even need to mention this.
>
>
> Best regards,
>
> Rob Housman
> Europa XS A070
> Rotax 914
> Airframe complete
> Avionics a work in progress
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Andrew Sarangan
> Sent: Saturday, November 09, 2013 3:58 PM
> To: Europa List
> Subject: Re: Europa-List: Fuel tank fluorination
>
>
> 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 isn't
>> 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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