BRACES (CALIPERS) 555
Making the polypropylene (or polyethylene) brace
Steps A and B are the same as described for Method 1 (see p. 552).
Step C. Heat-molding the plastic brace
1. Put the rod of the plaster mold
into the vacuum pipe. Be sure it is
very tight. (If not, take it
out and bend the rod a bit more.)
2. Stretch stockinette or
stocking tightly over the
cast and tape it to the pipe.
3. Sprinkle dry plaster powder
or talc over the entire foot
and smooth it with your fingers.
4. Preheat the ‘oven’
and sprinkle plaster
powder or talc
evenly over
the hot
metal sheet.
5. Cut a piece of polypropylene
plastic large enough to stretch
around the entire toot, and put it
into the oven to heat.
6. As the plastic gets hot
enough to mold, it will turn
clear so you can easily see
through it. It often gets
clear in the middle first.
7. To move the hot
plastic, 2 persons
must wear thick
gloves. Sprinkle
dry plaster
powder, lime, or
talc on them.
8. As the plastic is getting
hot, turn on the suction
(vacuum cleaner) and listen
for a hissing sound where
the pipe joins the
cast. (This means
the suction is
working.)
9. When the plastic is hot enough (clear
and limp), remove the oven lid, lift the
hot plastic by its 4 corners, and
quickly stretch it over the whole cast.
10. Quickly pinch the edges of the plastic
together along the bottom side of the leg
and around the pipe. Squeeze together
all edges to form a seal. You must work
quickly to complete the seal before the
plastic gets too cool.
As soon as the
seal is complete,
the suction should
pull the hot plastic
close against
the cast. But if
necessary, help by
pushing it into the
hollows.*
11. While the plastic is still
hot and soft, cut off the
extra with a sharp knife or
strong scissors.
12. After it cools, draw
the form of the brace
on the plastic,
13. and cut it out
either with a cast
cutter,
or a hammer
and chisel,
or a red hot soldering
iron, or however you can.
Finish the brace in
The way described
under Method 1
(steps 20 and 21).
* If no suction equipment is available, you can heat mold the plastic by stretching it over the cast and pushing
in the hollows until it cools. With practice, this gives almost as good results, and you only need about half as
much plastic.
disabled village children