I doubt anyone who has ever made a pattern or figure for casting would dispute the necessity of preplanning. However, I don't believe that this planning necessarily means that there is only one way to accomplish the goal. For myself, as alluded to earlier, my preference would be to sculpt in individual pieces without recourse to the saw. Still I wouldn't discount the value of a good piercing saw, especially if any of your pattern work is in brass, nickel silver (some other metal) or even plastic.
Patterns made for use in a high temp vulcanization process often are best made from metal of some type and silver soldered together, although green stuff is certainly an option. I know of and have known guys who always sculpt everything, and never have to resort to the use of metal, however these guys-in my experience, limited as it may be-don't usually make patterns of mechanical or machine made prototypes, railway wagons auto parts, that sort of thing. I also know a guy that makes his patterns in large part from 'white metal' blocks (and this guy has full time employment, not commission based, as a pattern maker), basically carving the parts with a rotary tool, finishing up with the addition of necessary small bits, bolt heads and the like, all soldered together. The real difficulty of metal pattern making is the assembly of multiple small bits to make up a larger detailed component for casting. Making up sub-assemblies, which really is what we are talking about, is the easy bit, parts are simply made as such, completely separate from start to finish.
Back to the topic of figures originals for production casting; I’ve seen larger sized figures broken down during the molding process by the strategic placement of temporary dams to create part lines. It works, but is very labor intensive the molds needing to be made in succession rather than all at once. I've seen guys, and have done this myself on more than one occasion, create a 'mother mold' from a single piece original; production patterns are subsequently made by chopping up castings gotten from the 'mother mold'. Again, this method works nicely but is much too labor intensive to want it as a standard technique, at least for me. Another technique that works well with sawing, and indeed preplanning, without need for repairing detail or mass lost creating part lines with a saw is; to sculpt a complete rough armature without detail or surface finish, saw the part lines and reassemble with pins (made from wire) creating a barrier between the parts during assemble. The barrier is an obvious necessity as the assembly of parts is temporary after all-Vaseline and liquid latex (as mentioned earlier), make fine barriers. After this reassembly and barrier creation sculpting proceeds as normal, almost though not quite, as if the sculpt is being created as a single piece for casting in one part. This method works nicely because of the bulk already available for sculpting on, unlike a bear wire armature. Works, but isn't my normal procedure. Typically I sculpt all the larger masses first adding those parts that are to be cast separate as the last stage with the requisite Vaseline or latex barrier between. Basically the same method advocated by Mike.
In the end what I am attempting, though probably not too well, to illustrate is that there are indeed a variety of useful techniques available to the pattern maker, many of which I have not mentioned or am not at all familiar with. What we all do is develop or learn techniques that work well for ourselves, some better than others obviously. However, if the technique adopted works for any particular individual I wouldn't, myself, be comfortable with-or even think myself qualified-to name another’s working techniques as being wrong. Besides which, whenever I run across a new technique I always, at least, give it a thought even if I don't actually try it out or, even if my initial reaction is that the technique is somehow wrong or useless.
That’s the extent of my two cent defense of any other weirdo that simply has to do things his own way, even when perceived by others to be wrong.
Best Regards All,
Ray
Ray
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