"Franz Heymann" wrote in message ...
I am mean that lightweight double-skinned stuff which can be cut with
a pocket knife. It has an overall thickness of about 5 or 6 mm. It
is translucent, but not transparent.
Which urgler would like to report on its usefulness for making
"rectangular cloches", or small portable frames?
What does one use for gluing two pieces together?

Plain single sheet polycarbonate can be bent like steel, and drilled
and bolted to make a box or ridgetop shape.

the box section stuff would have to be mitred and glued, ordinary
contact adhesive might do the job for a while, or specialist stuff
like:
Evo-Tech TU1908, or Extru-Fix. Or you could make a lightweight wooden
frame and screw the polycarbonate to it.

I'm not sure about translucent frames being good enough for forcing
plants at the start of the year.

"Robert E A Harvey" wrote in message
om...
"Franz Heymann" wrote in message
...
I am mean that lightweight double-skinned stuff which can be cut
with
a pocket knife. It has an overall thickness of about 5 or 6 mm.
It
is translucent, but not transparent.
Which urgler would like to report on its usefulness for making
"rectangular cloches", or small portable frames?
What does one use for gluing two pieces together?

Plain single sheet polycarbonate can be bent like steel, and drilled
and bolted to make a box or ridgetop shape.

the box section stuff would have to be mitred and glued, ordinary
contact adhesive might do the job for a while, or specialist stuff
like:
Evo-Tech TU1908, or Extru-Fix. Or you could make a lightweight
wooden
frame and screw the polycarbonate to it.

All very useful information to bear in mind.

I'm not sure about translucent frames being good enough for forcing
plants at the start of the year.

I may be wrong, but I am under the impression that the translucent
material does not necessarily absorb a significant fraction of the
incident light, but that it simply scatters it. If I am right, there
should be no problem about forcing plants early in the season.

Franz

In message , Franz Heymann
writes

"Robert E A Harvey" wrote in message
. com...

All very useful information to bear in mind.

I'm not sure about translucent frames being good enough for forcing
plants at the start of the year.

I may be wrong, but I am under the impression that the translucent
material does not necessarily absorb a significant fraction of the
incident light, but that it simply scatters it. If I am right, there
should be no problem about forcing plants early in the season.

If it is the same stuff as I am using (intended for conservatory roof
applications) it may transmit around 6% less light due to the internal
structure and being double skinned. But it more than makes up for that
by providing better insulation. I have known other cacti growers use
this stuff to great effect in their greenhouses (and intend to do the
same).

I'd be a bit less convinced by the 6mm grade. I reckon that may reflect
back as much as 10% of the incident light. But even then it may not be a
real issue since it is the warmth that encourages early germination.

Regards,
--
Martin Brown