Exhaust Tape

Scott

If the tape wrapping is any good it will be made from ceramic or aluminium
oxide fibre with a foil on the outer surface to reduce erosion of the fibre
in service. The fibres are usually held together with a binder, so that you
can work with it without the stuff falling apart. After some service, the
binder either burns away or sets in the shape it is in, meaning that you
would normally irreparably damage the wrap by removing it after service.
How well it insulates depends on the thickness and the diameter, as well as
the so called "shot content" with ceramic fibre. Anything over 5 micron
diameter causes skin irritations (like everyone knows from fiberglass).
Under 5 microns this is reduced, but the risk of inhaling the stuff
increases.

An exhaust system can be perfectly reliable with insulation, provided it is
made from a high grade steel and has been designed with either slip joints
or bellows to compensate for the thermal expansion. I think that slip
joints are more common in aircraft designs, since the system does not have
to be absolutely airtight.

In most cases, working with a known cracked exhaust system can be a waste of
time, unless you are willing to do dye penetrant tests to locate all the
other cracks that there are bound to be, but are too small to see with the
naked eye. Ceramics do not melt at the temperatures that cause steel to
flow, hence weld contamination is a major problem.

Regards
Keith
"Scott" schrieb im Newsbeitrag
...
Thanks everybody for the replies. .

It sounds like the wrap does work but would require extra attention for
inspection of cracks. Does it stick to the pipes? Can I remove it
every annual or every other annual to inspect the exhaust pipes?

I have heard about ceramic coating the pipes. Can this be done after
they have been used for a few hundred hours? Also once they are coated,
does the ceramic interfere when repairing them, ie..welding a crack?

thanks,

Scott