On Sat, 3 Mar 2007 22:53:58 +0100, "Rob Turk"
wrote:

clare at snyder.on.ca wrote in message
.. .
On Sat, 3 Mar 2007 08:36:23 +0100, "Rob Turk"
Can you hog it out to the next size pipe thread and put a reducer
bushing in? Make sure you use a tapered pipe thread and do not
overtighten it. Make sure you use FLEXIBLE line from the tank to the
fuselage. Rigid tubing WILL eventually take the threts out of the poly
tank.


That would get me back to the starting situation; What do I use to seal the
bushing, considering nothing seems to stick to polyethylene..

Rob

Buna or "Viton" o-rings as are used on o-ring fittings, face seal
fittings, and flanges the world over. Compress, don't twist. I don't
have a link to the AN series, but SAE (J1926) or BSPP (ISO 1179) work
well with light hydrocarbons and alcohols. My specific experience is
in hydraulics where they are used from vacuum to about 600 bar (9000
psi)

I'm making one REAL BIG ASS U ME thing ... that you can get into the
tank to install a nut. IF not, the expansion plugs mentioned earlier
are a good option.

Note that these fittings are usually steel in my industry, but the AN
versions are also in aluminum; you'll pay more, save weight, but get
the same ports.

Aside; whoever said teflon tape is attacked by gasoline ... I'd like
more information; I've used it many times with no problems of that
sort. My objection with it in a fuel system is that the installation
will leave small particles that plug orifices ... like carburetor
jets.