• Place the outer mould on some newspaper on a workbench.
• Mix 200g of resin, with 3cc of catalyst (and 15-30cc of pigment for colour, if
required). Use no talcum powder in the first two mixes.
• Paint this resin all over the inside of the outer mould. Do not paint it on top of
the island in the centre.
• Apply one layer of fibreglass mat (CSM), and paint more resin over it again, with a
poking motion to remove bubbles. Work the resin into the CSM.
• Apply a second layer of CSM to the wall, but keep one disk for later.
• Put the coils into the mould. The wire tails all come out in one place, between
coils 3 and 4.
• Mix another 100 g of resin with 2cc catalyst. Pour this over the wires of the
coils so that it soaks in. Avoid making 'pools' of resin.
• Mix another 600g of resin with 9cc catalyst and 600g of talcum powder. Pour
this mix into the spaces between the coils. The resin should fill the outer mould
until it is level with the island at the centre.
• Shake the mould vigorously, to remove air bubbles. Rotary motion and vibration
will help the resin to settle, and help any air bubbles to rise .
• Mix another 200g resin with 3cc catalyst and only 100g of talc. Put the second
CSM disk over the coils and paint it with this mix. Thoroughly wash out the paint
brush with thinners.
• Put the inner mould down inside the outer mould, and fit the 12 mm bolt though
the centre of both. Tuck the wiring neatly into the space between the moulds.
One flat spot on the inner mould sits over the part where the wires come out of
the stator. The resin will rise up the sides. Some resin may spill out.
• If necessary, pour resin gently into the gap between the moulds until it rises to
near the top of the female mould. You may need to mix another 100g of resin with
1.5cc of catalyst to do this. Keep notes of the amounts of resin used, for next
time.
• Place the jig (for the studs - diagram 24) over the inner mould, with one end over
the wire tails. Tighten the 12mm bolt with a nut. Insert the four 8mm studs into
the holes, with nuts on top. The studs should be immersed in resin for about half
of their length.
PMG manual
Six stages of the rotor casting procedure
page 29
June 2001