On Wed, 19 Mar 2008 21:04:46 -0400, John
wrote:

Does anybody still do the old technique of drilling holes before tacking
tubes together to interconnect them for oiling the fuse when it's
finished? I've been told that's not done any more, because of the
realization that as long as the welds are air tight, the oxygen trapped
in the tube is consumed in a small amount of oxydation of the metal
surface inside until all that's left is nitrogen and then it's fine
without any oil inside.

Comments?

John


my old Auster had a section where the drain holes in the fabric had
been forgotten.
the rudder particularly had been flying around for years with about 9"
of water in the bottom of it. there were lots and lots and lots of
tide marks in the fabric where the rusty water had partially dried out
then refilled.
needless to say the entire lower tube frame of the rudder was corroded
through in a number of places.
when we cut the corroded section away and looked into the tube, an
eighth of an inch away from the rusted through area on into the rest
of the tube the tube was pristine.
the poms had swabbed out the inside of the tube with lanoline.

skimp on the little eighth inch holes all you like and dont bother to
put tube seal in the tubes. they're such a bother.

....might just bite you in the arse one day.

soaking all the auster fuselage tubes took less than half a can of
tube seal and even with our import costs was under $20.
for that I have a totally corrosion free fuselage and it will stay
that way.

experimenting is such fun. go for it.

Stealth Pilot