Fuel additives

[aviatoreb]

Quote: kortopates

Thought I add my two cents to this discussion and reading....

...Definitely, IPA or Isopropyl Alcohol is the only approved additive for our Mooney per both your POH and Mooney SI M20-64, which limits it to quantities not to exceed 3% for the Continental’s and 1% by volume for Lycoming powered models*. It must of course be anhydrous IPA, not your drug store variety blended with water. 

...The primary reason keeping me from adding IPA is that it will trash the rubber o-ring in your fuel system components. I know of one K owner that added it regularly every winter and then found it trashed all soft rubber parts in his fuel system after 4 years. 

...BTW, its Bruce Jaeger, not Yaeger and he’s certainly seen a lot of this in MN and an excellent person to discuss directly with. I’d bet he would recommend adding a conservative amount each winter to be safer...

...Kudos though, for raising questions about this as a new turbo owner. Still, I think you’d benefit from hearing from someone with many years of Rocket experience. But so far you’ve heard from one Rocket owner is reporting no issues in very cold conditions.

[BorealOne]

Most industrial chemical suppliers should stock it - it's a pretty common chemical. Also check industrial paint suppliers - it's commonly used in prep and clean up. Should run about $25 for a 1/2 gallon.

[aviatoreb]

Quote: borealone

Most industrial chemical suppliers should stock it - it's a pretty common chemical. Also check industrial paint suppliers - it's commonly used in prep and clean up. Should run about $25 for a 1/2 gallon.

[kortopates]

Hi Kelly, it was great to meet you too. I can't say why such dilution levels of IPA degrades fuel system rubber components except relay what Dan, a K owner, came to that conclusion after talking to Ed Kollin of Camguard while at OSH. Apparently till then, no one gave him an explanation as to how his fuel pump, fuel divider and mixture control got trashed internally. It was sometime after he had repaired his fuel system during Ed's talk at OSH that the connection was made after the discussion went from oil additives to fuel additives such as etoh and then the light went on... Dan reportedly was using IPA concentrations of 0.4 to 0.8%(10oz per 10 to 20 Gal) over 4 years before his engine began idling very rough and then began the process of changing out o-rings till eventually he had everything rebuilt and finally a smooth idling engine again.

I may be being overly cautious out of concern for protecting my fuel system, but given how little water is absorbed by 100LL I do expect I'll get ample warning to correct well before my engine goes quiet at altitude -knock on wood! So far, there are many K owners flying without adding IPA reporting never a miss as my own experience. However, I too can really appreciate those living in much colder climes just wanting the added insurance in avoiding a fuel icing encounter. Obviously, everyone has to access their own situation, as in YMMV.

[David Mazer]

If we should use 1% alcohol on a 100 gallon tank, that would be 1 gallon per tankfull at $25/half gal that is an additional $50/ fill up.  That adds 10% to the cost of fuel at $5/gal.  Seems steep.

[Awful_Charlie]

I get pure IPA from a friend who has a friend in the chemical biz ;-)  It's near as dammit 2GBP a litre (12USD/gallon) so more or less the same price as AvGas over here :-/

[aviatoreb]

Quote: Mazerbase

If we should use 1% alcohol on a 100 gallon tank, that would be 1 gallon per tankfull at $25/half gal that is an additional $50/ fill up.  That adds 10% to the cost of fuel at $5/gal.  Seems steep.

[aviatoreb]

Quote: Awful_Charlie

I get pure IPA from a friend who has a friend in the chemical biz ;-)  It's near as dammit 2GBP a litre (12USD/gallon) so more or less the same price as AvGas over here :-/

[sleepingsquirrel]

If one has to put alcohol in the fuel for water freezing protection, why not just do the math and put MOGAS with Ethanol in for this purpose. Seems the discussion is "gotta have it" in spite of its bad effects to prevent freezing . Mogas is cheaper per gallon and would accomplish the same purpose. Wink, Wink!

[jetdriven]

Isoprtopyl alcohol and ethanol arent really the same thing. 

[skyking]

I see temps of -50 ( yes -50) on a regular basis here in Northern Alberta and i have never used any additives.

I just make sure the plane has a good pre heat. Mine is stored in a hanger no matter where i go if i can get one but i have had to park outside in heavy rain and to this day i have never found water in the tanks.

 

PS; we dont fly if it is colder than -20.

[jetdriven]

The water in the tanks at that point is already frozen and may precipitate out.  The only danger I think is clogging a screen with ice crystals.  This brought down a 777 in London.

 

[sleepingsquirrel]

I stand corrected, from the Car Guys;

Most fuel system antifreezes contain %100 isopropyl alcohol. The reason being, just like ethanol it absorbs water. The difference is when isopropyl alcohol absorbs water it doesn't phase seperate out of the gasoline. It keeps the water in suspension in the gasoline so it can be carried off and burned in the engine.