This is the method I've used to glue the fuzzy back bellows cloth.
I realize that many of the MMD readers are familiar with the basic
procedures of recovering bellows but I've made the instructions as
detailed as I can to help the novices in our group as well.

Cover the hinge end first using a piece of bellows cloth large enough
to overlap on all four sides of the hinge end.  Double glue it in place
by applying glue to the hinge end and to the fuzzy side of the cloth.
Push the glue into the nap of the cloth with the glue brush to achieve
good penetration then press into place and let the glue set.  Later,
trim the excess cloth off using a single edge razor blade or a razor
knife.  Use appropriate care when using these tools, it's easy to get
cut if you rush or are careless.

Cut your cloth to size.  The length of the strip of bellows cloth
should be the width plus the length of the bellows board times 2.
The width of the strip is equal to the span of the bellows you are
recovering.  Measure the open end of the bellows with the original
material still in place from outside edge of one board to the outside
edge of the other board.  That is the span.

Lay your strip of bellows cloth on a clean, flat surface so that the
cloth is laying lengthwise to your left and right.  Measure the length
of the strip and mark the center of the cloth.  Measure the width of
the bellows board and mark the center of the board on the inside at the
open end then place the open end of the bellows on the cloth so that
both center marks meet and the outside edges of the bellows are lined
up with the edges of the cloth.

Tilt the bellows so that it is laying on it's side insuring that the
two boards do not move inward or outward.  Apply glue to the ends of
the two boards then roll them up onto the cloth.  Tilt the bellows back
down on it's side and pull the cloth away.  The glue marks the cloth
where the boards will be glued.  Apply glue to the cloth, pushing the
glue into the nap of the cloth then an additional thin coat is applied
to the boards.

Roll the boards up onto the cloth then onto it's side again.  Press
and smooth the cloth to the boards with your fingers, working from the
center to the end insuring a tight bond has been achieved.  Wipe away
any excess that may squeeze out at the ends of the boards or you may
have trouble getting the cloth to make a tight seal at the corners.
Stand the bellows on it's open end and let the glue set.

If an outward pressure leaf spring is to be installed, do it now.  Try
to get it in the same place it was originally.  You should be able to
collapse the two boards and the tail of the spring should remain
centered between the two boards without touching the boards.

Next are the sides.  With the bellows standing on the newly glued open
end, rotate everything 90 degrees so that the flat sides of the boards
are facing to your left and right.  Pull the hinge end towards you
laying the side of the bellows on the strip of cloth.  While holding
the cloth so it is smooth and flat and won't move, push the hinge end
so that the cloth is slightly stretched and tight.  Mark on the cloth
where the hinge end meets the cloth for reference.  You will have
a mark that looks like this:  \_/

Stand the bellows up and apply the glue to the sides then bring the
bellows down to the cloth to your reference mark.  Stand the bellows up
and remove the cloth.  Apply more glue to the cloth and bellows as you
did for the open end and tilt it down to the cloth.  Flip the bellows
so that the newly glued side is facing up.  Pull the tail of the cloth
in a slightly downward direction against the hinge end while pressing
the cloth to the sides with your fingers working from the open end to
the hinge end.  The other side is done the same way.

Double glue the hinge end.  The tails of the cloth should just meet
but should not overlap.  It's OK if they don't meet as long as they are
long enough to go around the corner and there is sufficient a amount of
cloth left to glue to the hinge end.  Let the glue set then trim the
cloth.

A few things to remember: Use enough glue to create a good bond but not
so much that you have glue oozing out making a sticky mess.  Don't be
in a hurry.  Allow enough time to pass between steps to let the glue
set on the open end before proceeding to the sides or your cloth may
move and you will need to start over.  Use hot glue.  It sets fast and
is removable, should the need arise.  Don't dribble glue anywhere on
the working surface of the cloth.  This method works for leather as
well.

One more hint.  On bellows that have a leaf spring inside, I tack a
strip of scrap strip of bellows cloth about 2 inches wide across the
open end of the bellows so that the bellows will open almost all the
way, but not quite.  The stress of the spring pressure is on the strip
but not on the bellows itself.  It makes for a longer lasting job.

I've had good success in the past using this method.  Give it a try.
Good luck.

Bob Moore
Orlando, Florida