Steve Firth wrote:

As it says for some reason the industry is very cagey about giving full
details of the types of epoxy used in different applications. The Lotus
glue is an odd one, a heat cured epoxy. That wouldn't work for large
aircraft. The Wings on most modern aircraft are bonded using an
epoxy-polysulphide adhesive (I think, but I'm not sure).

The phrase epoxy-polysulphide doesn't hold up with me, though I could be
wrong, as I have been out of it for ten years now.

Epoxy suggests a 2 part mix, like Araldite.

Polysulphide suggests a 2 part mix that produces a synthetic rubber type
mix. A company that makes this is called Thiokol.

If an aircraft wing is not made of carbon fibre, then the aluminium is
joined using an interfay that is defined by the manufacturer. This can
be all sorts of things, but the cabin skins are usually interfayed with
one of the polysulphide compounds to prevent cabin pressure losses. This
is like joining the various skins with a water proof, air tight seal.

Take a close look at any aircraft and you will see that it is a
patchwork quilt of skins, rivetted to the cabin stringers and stations.
The stations being the frames that form the shape of the diam. of the
fusalage.

The size of the skins is down to the time that the interfay is applied,
to the final rivet goes in to that skin. Before the interfay goes beyond
workability.

Dave