Evaporated fuel residue

[Wayne 2]

Hi All,

I’ve discovered the header tank in my project KF (sat for 6 years before I got it) has LOTS of yellowish granular goog adhering to the tank walls, due to total fuel evaporation.

Tank now out, need to flush.

white vinegar any good?

 

Wayne

[109jb 181]

Depends on what kind of tank. If it is a polyethylene (plastic) tank, then use denatured alcohol. Will dissolve the goo easily. Don't use on fiberglass, at least not without testing  first to see if there are detrimental effects.

[Wayne 2]

Sorry, I should have said.

‘it’s the welded aluminum tank.

thnx

[TJay 1041]

Put a few nuts and bolts in there and shake it around too

[109jb 181]

Denatured alcohol on the aluminum is fine too.

[Avidventurous 22]

I gotta wonder if new gas would dissolve the old gas......

[109jb 181]

I gotta wonder if new gas would dissolve the old gas......

Definitely not as fast as denatured alcohol, if really at all.  In the old days I used to use auto gas as cleaning solvent for carb parts and it never did very good at removing varnish from carb bowls and such. Denatured alcohol on the other hand dissolves old gas and varnish almost immediately. Since I discovered this I always have some on hand and use it for cleaning carb parts where I used to use stuff like berrymans dip tank, mineral spirits, etc.

That said, On the kitfox I recently rebuilt there is a 6 gallon fiberglass wing tank that had/has a bunch of gunk in it from evaporated car gas. Not knowing if the denatured alcohol would harm the fiberglass, I decided to cap the outlet line and put in 3 gallons of 100LL with hopes that flying around and letting that 100LL slosh around in there will dissolve that junk. For now I am flying it only on the 10 gallon polyethylene tank between the instrument panel and firewall until I can get the wing tank clean enough to flow uncontaminated 100LL from it. I unfortunately have no place I can get ethanol free car gas, so that tank will only see 100LL for now.

[Wayne 2]

Hello All,

Thank you for your input. Here’s what happened.

I realized I needed to remove the header tank to slosh it, so I did.

First, I tried fresh Mogas. Nope. So then, alcohol. Nope. Then white vinegar. Nope. Then, hardcore, carb cleaner. Much better. Think I got it all. So, reinstalled after 2 weeks of effort, had flushed both wing tanks and verified good, then used the boost pump to verify the line up to the inline fuel filter, which seemed fine. The filter when cut open was clean, but I replaced it.

I think this algae looking stuff with some grit was all settled in the header tank and none got to the carbs. Carbs now balanced and running sweet.

But look at the sheer volume of this sediment. One header tank completely evaporated over 6 years.

Wayne