As we all know, it takes thousands of years for rocks to be created. Fortunately for modellers, even those of a serious armchair disposition, we can make our rocks a little more quickly!
A while backI had an email to-and-fro with Joel Bragdon of Bragdon Enterprise about purchasing some of their rock moulds. I had used a Bragdon mould for the harbour walls and was very impressed, so purchasing their rock moulds for the rest of the layout was a no brainer, so some money was duly sent to America and I waited.
After Customs had kindly held on to my parcel for quite some time, and Parcel Force charged me for their part in delaying it’s arrival, I was in possession of three moulds.
The intention with these three was to use them to cast all of the rocks on the layout. They are far larger than any one section needs to be, so I can use various smaller areas cast from the moulds and avoid too much repetition of pieces on the layout.
I used some casting plater bought from a local hobby store, this was nice and fine and enabled the beautiful detail of the moulds to be well represented. Each mould was given a spray with isopropyl alcohol to ensure that the surface tension of the plaster was broken, allowing it to flow well around the mould. Plaster was then mixed following the instructions and spooned into the mould. Now, as the moulds are rather large, to entirely fill them would result in me adding about 15kg to the layout weight! So, to avoid this, I used a small quantity of plaster and, as it was drying, I pulled it around the mould to form a thin skin. The following YouTube video neatly captures the method I used.
As the shape of the landscape was quite complex I decided it was best to just cast the rocks to the unadulterated shape of the mould. So to form them to the landscape I snapped them into sections and then fixed them in position with PVA glue.
At this point I took great care to make sure that all the different sections were orientated the same way so that strata continued where possible.
To connect the different sections of castings together the same plaster as used for the castings was mixed, only this time thicker to ensure it’s not too dribbly to apply to the castings. It’s important to use the same plaster as it will accept colour in the same way as the castings, and therefore is less likely to show up once finished. The thicker plaster is then applied to the gaps with a small trowel, and allowed to harden until a skin has begun to develop.
Once there’s a skin then I used the same trowel to roughen up the surface and make it less regular. Following this I brushed the plaster with a toothbrush (an old one, before anyone asks…) to ensure it’s not perfectly smooth, and provide some natural variation. Then the plaster is attacked with a scalpel and carved to match the surrounding rocks. This step should help make the joins indiscernible once the scenery is finished.
The baseboard joint runs through the headland, I placed it here deliberately to try and avoid having it running through the sea for any great distance. To help make it less obvious a rocky outcrop will come out of the sea right at the front of the baseboard immediately in front of the headland.
Once the gaps have been filled with plaster and carved to the desired shape it’s time to move on to blending them in to the landscape.
Inevitably the castings won’t perfectly match the land around them, so some filling is required. This time I plugged the small gaps with crumpled tissue paper and then clad this with paper mache made by soaking the local freebie newspaper (well, there has to be at least one use for it!) in a diluted PVA glue mix.
I won’t be colouring the rocks before the exhibition at Sparsholt as I haven’t yet built the lighting for the layout, so I’m trying to avoid adding too much colour until I know what intensity lighting the layout will be shown beneath. There is guidance on how to paint the moulds on both the New England Brownstone and Bragdon Enterprise websites. I will likely be following a mixture of the two of these sets of instructions when I come to paint my rocks.
And finally, the end goal… well, hopefully it will look something like this: