In a message dated 4/9/2001 12:52:24 PM Eastern Daylight Time,
terrys@cisco.com writes:
> What have
> other builders done with the hoses
> going onto the tank outlets, tank
> filler, and tank vent tubes?
> Have you put the hoses on dry
> or with some kind of sealant?
>
I used a light wipe of moly grease (black) on the fittings when installing
fuel hoses to ease the assembly. This turns out to be the wrong thing to do;
the hoses should be installed dry or with a few drops of fuel or light oil as
lubricant according to my tech advisor. The problem is that a small blob of
grease can collect as the hose is installed. As fuel is pumped through the
line, this little blob can break loose and be pumped along with the fuel.
The real problem would occur should a blob of grease break free and lodge in
a carburetor jet at a critical point on takoff.
Same kind of process found in people when a piece of a blood clot breaks off
and moves into a position where it can cause trouble i.e. a CVA.
Sure enough, I noted little pinhead size blobs of grease caught in the fuel
filters after the first engine run. My tech advisor suggested waiting a bit
to see if the grease melted in the fuel, which it did -- this is fortunate
but still leaves one a little queasy about the possibility of a larger blob
lurking somewhere and floating free later. I cleaned the carb float bowls
and found a couple of specks of grease there also. Checked the filters and
bowls again prior to first flight and no more grease was found. It was
fortunate that I used black grease, otherwise it would have been impossible
to see and evaluate the effects of this grease.
As far as fuel smell, it is noticeable initially when the doors are opened
prior to installing the wings but disappears quickly. It's not noticeable
during use since the airflow through the cockpit changes the air very rapidly.
John N44EU
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