Quite true, alternatively you could hold the part inside a rotating drum, a bit like rotational moulding. But then it will be harder to predict the thickness.

Quite true, alternatively you could hold the part inside a rotating drum, a bit like rotational moulding. But then it will be harder to predict the thickness. I suspect you are right about spraying, much more likely to get a uniform thickness. Maybe a combination of the two spray a constantly rotating (in 2 axis) part.