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Barad-dûr - Moulding and Casting
With these, we would go around the studio model and try to count how many of them were on it so we could give Bruce an approximate number required. We did get close to one hundred tiny patterns from which Bruce cast out close to one thousand pieces. That was just to produce the first pattern of Barad-dur. The real difficult task, was then on Bruce and that was to make moulds of the final patterns and cast out the mould and paint masters.
These two shots show all of the forty one model made and sculpted patterns ready to go to Bruce, for moulding. It is amazing to look at this shot, and know how many months of work for Leonard, Steve, Bruce and myself went into producing these patterns. My entire workshop was filled with parts of the studio model, three model makers and many patterns being built and sculpted. This went on for months and another large section of the shelves were slowly taken up with Bruce’s castings.
Then, it all finally condensed down to this area of a shelf; this was the master pattern of Barad-dur, the only one on existence so there was a lot on the shoulders of Bruce, to get the next stage right.
There was a lot of unknown at this point as we did not know for sure if this was the correct breakdown. With silicone moulds and resin castings, there is shrinkage and that varies depending on thickness, cure time, heat and a few other factors.... basically, difficult to predict. Bruce had to make many educated guesses about breaking these patterns up; firstly to give him something that can be moulded and cast and then something that will fit accurately back together again. The best option, with silicone moulds is to have as few as possible cuts, to get the resin components out. The more cuts, the harder it is to put the mould back together again accurately for the next resin pour and we have more seam lines to clean up and that become very critical on such detailed components.
The main part of an early team get together, is to try and figure out any problems and what steps we can take to help solve them, and this often informs how we build the model. If this was to be a ‘one off’ it does not matter, but this has to be copied several times, so we have to build it with this in mind. All the final resin castings have to fit back together again. There are several techniques we can use to refit castings allowing for shrinkage and with solid pieces, it only requires a tiny fraction to stop it fitting so we build in flexibility. If it is a large surface area at the join, we bevel the edges, on the inside so only the outer edge touches and a little hot water softens the resin enough to squeeze it together.
This is one set of final castings and Bruce does six of these so, soon we had a new stack of six times castings building up on our shelves.
Don't miss the first two articles by Dave:
We continue with great anticipation on Dave Tremont's journey to Barad-dûr.
The turn has come to tell the story of how Bruce Campbell, the mould master, sets out on casting all of Dave's tiny little patterns for Barad-dûr - Fortress of Sauron.
At the start, while ‘thinking about’ this job, all I had were several close up images of the big studio model and one long shot. So while waiting for more information to come through, I put together a cost and time guestimate and basic feasibility study. I tried to work out how long it would take to build several detail panels then guess how many to cover the entire surface. This was by no means accurate (at this point) but was to get me into the ball park of if it could be affordable as a collectible. The one thing that really became apparent, the more I looked at the pictures, was the amount of repeated detail panels and it occurred to me that the unreasonably high cost to build this model could suddenly be halved because everything is repeated.
This then made the project doable and would now have a large moulding and casting content and important to get Bruce involved at an early stage. The first costing was to put the project out of reach for ever, the second, while high, was possible. Building one small pattern could take three days and for Bruce to cast me six copies would be two days and the greater majority of that time is waiting for silicone and resin to dry, so he can produce dozens of pieces, in that same time by doing bulk moulding and casting.
Above images are; myself and Bruce discussing ways to break the model down into castable sections, and then Bruce opening one of the many moulds. Amongst many other tasks, Bruce Campbell is responsible for all the moulding and casting of our collectibles and so is involved, from the start, in determining how a sculpt will be broken up into mouldable components. With Barad-dur we knew that there were going to be many small patterns to build but we did not know just how many because every time we looked at the model we would find more pieces and it was impossible to count them. So, ‘a lot’ was to become a technical term and I would just keep making patterns and work out how many at the end.
Right from the start I focused on building small patterns and continued to feed them to Bruce, who would then deliver piles of resin copies.
Here Bruce is setting up a group of tiny moulds and then weighing out resin ready to mix and pour into them. Air bubbles becomes a huge problem as so the first part of the process is to put a fine dusting of talc powder into the moulds and this allows air to slide easily off the silicone.
After that the moulds are filled with resin then vacuumed to remove excess air then pressurized to finally eliminate any tiny bubbles left. Even mixing resin can introduce bubbles so the batch is vacuumed before pouring into the moulds. A very quick and easy way to make pouring funnels is to roll a piece of masking tape then hot glue it to the mould.
Above is just a random shot of my work bench, on any given day. Leaving all the little things on a board means I can pick the whole lot up, and move it if needed so I would sometimes have several of these boards, on the shelf or the bench in front of me and I change them around as needed. All the tiny patterns are built on small square boards which Bruce then uses to build his moulds on. I seem to gather a collection of small engineering squares and blocks to help build small patterns.
A couple of months into the job we were starting to get many containers of cast pieces which all have to be cleaned up before building onto the tower model. By now, Leonard had joined us and a lot of his earlier work was helping to build larger sections out of these kit parts.
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