Alodine & Fuel ...

AussieRV · #1 12-08-2008, 10:47 PM

RV fellows,

... i thought to cast my net across bigger oceans

I'm forward planning my fuel tank building and had a specific question about Alodine inside of fuel tanks - both skins and ribs.

Does it have any effect on fuel? ... are there any pros & cons? I've searched the site & threads to find the answer ... but nothing specific on the subject.

Many thanks in advance.

Cheers,

Matt

az_gila · #2 12-08-2008, 11:10 PM

Quote:

Originally Posted by AussieRV

RV fellows,

... i thought to cast my net across bigger oceans

I'm forward planning my fuel tank building and had a specific question about Alodine inside of fuel tanks - both skins and ribs.

Does it have any effect on fuel? ... are there any pros & cons? I've searched the site & threads to find the answer ... but nothing specific on the subject.

Many thanks in advance.

Cheers,

Matt

...and the specifications for the fuel tank sealers (aka ProSeal) actually quote a slightly higher adhesion number if the aluminum is alodined...

However, since there should be little moisture inside your tanks...

...the corrosion likelyhood is low and most builders don't bother with alodine inside the tanks.

AussieRV · #3 12-08-2008, 11:45 PM

Hey Gil,

Thanks for the response ... i'm thinking more along the lines of ease of the Alodine baths rather than corrosion protection ... but obviously the corrosion prevention factor is a bonus

Cheers,

Matt

airguy · #4 12-09-2008, 08:20 AM

Priming the interior of the tanks (and the ribs in them) is specifically a no-no, since the fuel has (in some cases) loosened the primer and you end up with trash floating around in the tanks. Alodining will not come off and serves as your primary corrosion prevention in the tanks, with the alclad becoming secondary prevention.

For the majority of tanks, on planes with builders planning to run 100LL or purely ethanol-free mogas, I don't see that it makes much difference. Where we may (in time) see a difference is with E10 mogas. The ethanol will increase the amount of dissolved water (very slightly, but an increase nonetheless) in the fuel - and this can lead to increased corrosion potential on aluminum surfaces. Alodining the fuel-wetted aluminum surfaces removes this potential problem and ensures that your tanks will not be an issue for running E10 mogas. The rest of the fuel system will have to be looked after as well to make it kosher with E10, but alodining will take care of the tanks.

Current theory on operating with E10 mogas is to alodine the fuel-wetted aluminum surfaces, get rid of ALL rubber gaskets and components from the filler neck to the intake manifold, and run electric fuel pumps in the wing root instead of a mechanical fuel pump on the engine block to avoid the heat-soak induced vapor lock that can occur with the higher vapor-pressure E10 under low flow rates (such as descent from altitude, or ground ops).

AussieRV · #5 12-09-2008, 03:16 PM

G'day Greg,

Thanks so much for the informative response ... it puts alot of questions to rest. Priming internal was never in question - this is a well known fact.

At this point i'm planning to only use 100LL, however i may be tempted to use mogas (ethanol-free) as here in Oz we have high grade 97 octane readily available ... offering considerable price varience.

Looks like the Alodine treatment for my tanks

Cheers,

Matt

Dean Pichon · #6 12-09-2008, 07:55 PM

based on the recommendation of the polysulfide manufacturer (for adhesion performance). Certainly no problems to date (8 years) and none expected!

AussieRV · #7 12-11-2008, 07:36 PM

.. thanks Dean

Vansrv7arob · #8 09-19-2012, 10:27 AM

Thanks for asking the question Matt, I plan to do the same shortly.

Bevan · #9 09-19-2012, 11:41 AM

Can an alodine process be applied to completed aluminum fuel tanks which have never seen fuel? If so, what is the process?

Obviously the surfaces can't get scotchbrighted or wiped or cleaned in any way. Does this matter?

Bevan

XOverZero · #10 09-19-2012, 03:47 PM

I'm still something of a noob here (2 yrs or so) and had not seen this question come up before. Very glad it did, as I've just started an RV-12 which will very likely run on mogas much of the time. Ethanol is a certainty.

It sounds as though Alodining the tank would be a plus for the -12, not critically necessary but a good idea for extra peace of mind. Do I read correctly?

I've used Alodine before...don't particularly like it because of the toxicity factor, but it's an easy process, so I could include it in the plan for the tank if it is significantly beneficial for protection.

Anybody got further pros and cons? Love to hear 'em.