Vasaline like goo in my fuel filter

[Wheels]

Hi,
I parked my kit fox model IV 1200 Rotax 912 80 horse to do some maintenance on the water system and inspect what appeared to be ice in the bottom of the glass filters from the wing tanks.

I took the glass filters out and removed the elements. There is a grey vasaline -like substance in the bottom. No evidence that it has made it downstream in any volume but I'm not sure what this is. The tanks are bran new ethanol resistant and have had about 150 gallons through them since install. I don't know what the mechanic used to clean them prior to install and I think he's dead now anyway. If he used any kind of sealant to insert fittings, it would have been fuel resistant and I can't imagine it ending up in my filter. I'll pull the gascolator filter next. I want to see whats in that.
Any ideas as to what causes such a gooey mess in a filter element?

[Av8r3400]

This *may* be the BSS (brown sticky shi-stuff - the release agent from the new tanks) before it turns brown.

It is very, very imperative that new tanks are rinsed out thoroughly and repeatedly with acetone to remove this material. Gasoline (aviation or auto), lacquer thinner, ethanol, soapy water, harsh language, whatever - won't take it out.

See Service Bulletin SB60.

[Flybyjim]

Is this the case for the new SS7 kits?

[Paul Z]

I have a 7 SS, I have had the sticky stuff problem. It takes some tome and money but easier now than when in a plane!

[Wheels]

The mech told me that he had rinsed out the tanks thoroughly, hmm I fired him a while back,(no, he's not dead) looks like I'll have to rinse out the tanks. but he will stay fired.

[Av8r3400]

Is this the case for the new SS7 kits?

Absolutely. Definitely. Any tank made since 11-2007, with a serial number etched on it.

[Wheels]

Thanks Av8r300, I'm on it.

[Marvk7]

I've ran across this topic several times but have not seen instructions on how to clean the tanks. What's the best way to do this on tanks already installed ? Do you just fill and drain several times?

[TahoeTim]

yes, on the tank is a sticker with instructions

av8r is incorrect, it says to rinse with 50/50 acetone and auto gas

[Av8r3400]

av8r is incorrect, it says to rinse with 50/50 acetone and auto gas

I posted a link to SB60. Here it is again. Direct from Kitfox says acetone.

The 50/50 mix with avgas is to ease rinsing if you cannot remove the wings. If it were my plane and this material was found, I'd be pulling the wings to get as thorough a rinse as possible, using the straight acetone method.