There is only one cement for perspex that is two part:

Tensol 70 with a hardener.

Then a Micromesh kit from Wings and Wheels for polishing.

Tensol 70 works by dissolving the two sides of the crack, then
setting hard and basically forms new perspex.

Tensol 12 a similar adhesive will stick but has no strength. Other
acrylic adhesives will stick but again have no strength.
As SXC says below its should be taken with care and plenty of
caution. It is liquid and runs and as it sets form strings and they
stick to canopies. so care and masking.

The process is simple, time consuming and requires infinite
patience. Space does not permit a full description of how to do
it. But small cracks are well within the scope of an owner.

The first step is to drill the end of the crack with a fine drill. or
hot needle. To stop it spreading. A red hot needle will give some
form of seal.

Dave





At 21:58 14 October 2013, SoaringXCellence wrote:
There are liquid acrylic "cements", actually solvents that melt
the
materia=
l. I have used it in the past, with a VERY small hypodermic
needle to
wick=
it into the crack. The solvent has very low viscosity and will
easily
dri=
bble out of the tube. a very small amount will travel a good
distance via
=
capillary action, into the crack and soften the edges letting
them fuse
tog=
ether. Keep something like a cloth under the point of the
needle until you
=
are really ready to start the wicking into the crack. this is to
prevent
th=
e solvent from dribbling onto the canopy in places you don't
want to
repair=
.. NEVER try to wipe off the dribble (BAD smear), if it happens,
let it dry
=
completely, and polish it out with Micro-Mesh or something
similar. You
sho=
uld orient the canopy so that you can work from above the
surface, with
the=
crack parallel the horizon, to prevent running. I usually work
from the
i=
nside, that helps to contain the solvent in the concavity of the
inner
surf=
ace.

Having said all this, and having repaired several canopies, I
always go
ver=
y slowly and cautiously when even considering the attempt. I
know about
th=
e "dribbles" and smears from experience and I sometimes
think the cure is
w=
orse than the disease.

Mike