We are attempting the retro formula and have the gravity correct for the wax but the wax is not doming and is "crusty"on top.Is this not enough heat,3x35w bulbs but no coil ?Do we need one ?We have used distilled water and salt {not pickling but sea salt unable to obtain pickling salt anyware in uk} it is also a flat lamp(vertical that is200mm w 250mm h 30mm depth)is that likely to cause a problem ?Thankyou for any input.
I believe you do need to add a coil. My own thinking is that the coil draws heat from the bulb and heats the outer edges of the wax, thus causing the wax to melt and flow upward.