In some cases, especially long bends with short sides, an angle made out of two pieces
of wood will help in making the final set accurate, Photograph 3, showing that long
narrow bends are easily possible.
I am sure that most first time users will be astounded at the ease with which bends
can be made and the quality of the result. In the case of multiple bends, bends can
even be made with the heater side on the inside of the bend, just proceed as above
testing for the material to become pliable, remove the item from the bender and bend
in the opposite direction. Photograph 4 showing an example.
Photograph 5 shows a full 180 degree bend having been made on a narrow strip. This
being something that would be quite difficult if attempting this with a metal workpiece
and shows the versatility of the method.
For the vast majority of the users the bender as described will suffice but if much
use is envisaged the following improvement may be worthwhile. Instead of making a
ridged assembly, the two boards can be hinged and one board lifted to form the bend.
The heater element
That is all that is needed to be said regarding the bender and its use, but as makers
of the item are likely to be faced with varying situations regarding the heater and
its power source, the following comments may help in establishing a working arrangement.
The time taken for the sheet to become pliable is in the order of 1 to 2 minutes.
For this the heater did not show any sign of becoming red hot but did attain a temperature
where it became coloured blue, as when tempering tool steel. The temperature was
therefore in the order of 280 degree C.
The faces on the three pieces of wood that form the channel in which the heater wire
runs were covered with self adhesive aluminium foil, prior to being screwed together.
The purpose of this was to reflect heat back into the heater and increase its temperature
and thereby speed up the operation. Whilst in theory this is surely true, I doubt
if it has sufficient benefit to warrant it being fitted, it most certainly is not
essential, though no doubt it also protects the boards from becoming scorched.