Isopropyl and fuel tanks/system

[Dave S]

We have had a lot of discussions on this list about compatibility issues with ethanol and the fiberglass fuel tanks.

What experience/knowledge to people have concerning isopropyl in the fuel system of the Kitfox particularly considering the fiberglass tanks?

100LL will often develop tiny ice needles in suspension in really cold weather - same-same with autogas without ethanol.

Some standard fueling practices with certified aircraft involve using a little isopropyl alcohol under these circumstances to prevent clogging of screens/filters.

What has been your experience/practice?

Thanks,

Dave S
KF7 Trigear
912ULS Warp

[mr bill]

Since the late 60s, we have used 1 oz isopropyl alcohol per gallon of fuel to prevent ice in the fuel system in the winter. These are Cessna and Piper with aluminum fuel tanks, using 100LL and mogas (unreformulated). Not sure about the effect of the alcohol on our fiberglass tanks. Reformulated mogas has a minimum of 13 ounces of alcohol per gallon.