It hasn't turned out anything liike I expected it to at the start, but it was all a process of experimentation, and trying different things, seeing how they looked, and seeing if they worked for the piece.
I had in my mind that the theme was 'the sea'. I then started by casting a boat-shaped block of herculite, with wire rods embedded into it.
I then shaped these rods into the two main curcular wave shapes. Then I put chicken wire over the rods as an armiture.
Onto this, I wrapped plaster bandage, and coats of herculite to build up the forms, letting it be quite organic in shape.
On the outside of the wave shape, I experimented with various different finishes, throwing pretty much everything I had at the surface and literally seeing what stuck. I had acrylic paints in yellow ochre, moss green, blue and brown, inks in black, sepia and a greeny yellow, and a dark teak wax. I also applied a copper finish and put chemicals on it to turn the surface green.
Inside the crevices of the piece, I put a sticky size with silver leaf on top, which I varnished.
On the inner edge of the wave (or frond of kelp, as it was starting to look more like) I cut thin sheets of copper, bent them to fit, and held them in place with a lip of herculite.
I then cut back the plaster, put an edge of copper acrylic paint on the plaster between the dark outer edge and plain white plaster surface (to look like the effect that you get on large shells such as abalones). Then it was a layer of shellac over the whole caboodle to bring out the depth of colour.
I'm pretty pleased with how it's turned out, as at one point it looked like something very unpleasant and long-dead that had washed up on the shore, and I thought it was beyond hope.
However, it's all a case of trying out a whole range of things, seeing what works best with the piece and getting rid of what doesn't - either by covering it up, cutting back the plaster, or getting stuck in with the sandpaper. The key is not to be precious! Experiment, and let the object speak to you.