This post continues from the previous Sculpting a 15mm Building Tutorial post.
Early 20th century buildings typically include a lot of surface detail they’re built from brick with added stucco or concrete rendered details over the top. Building details are fairly repeatative so I usually create a few simple masters for pillars and panels, and then cast them in resin to add to the basic flat wall described in the previous post.
The masters for these building details are small and constructed from various thicknesses of plastic card, super glue and green stuff. You should be able to create these detail pieces in an evening of sculpting. The photo shows the only masters I created for this second facade, apart from my generic 15mm windows. There’s a basic pillar which is made from plastic card strips, green stuff and some resin details I cut off an earlier pillar I made for my first 15mm facade. There’s also a left and right decorative bracket which adds to the roofline. Again this is constructed from the swirl piece cut from an earlier pillar, a scrap of plastic card and some green stuff.
Mold and Cast Details
Once these details are mastered I mold them, using the technique I’ve discussed in another tutorial and cast them in resin enough times to cover the facade. Be aware that casting in resin with some molding rubbers tends to destroy the mold as it leaches silicone from the rubber, eventually making it brittle and your mold prone to tearing and losing detail. That’s ok though because for this facade I only needed around 10 casts of the pillar.
You can see the RTV rubber mold in the photo as well. For resin molding I typically dust the entire mold with an un-scented baby talcum powder which acts as a mold release for the set resin pieces. The talcum powder will also help the resin flow into small details and corners. I use a 1:1 clear mix resin product from TopMark here in New Zealand. For European and US visitors I’m sure you can find an equivalent resin product from a local supplier. I mix the resin and pour it into the mold, and use a toothpick to lift and air bubbles trapped in corners before the resin starts to cure and turn opaque. The mold is then covered with an old CD jewel case cover, which has also been liberally dusted with baby talcum powder. This is because you want the detail casts to have a flat back, but you don’t want them to stick to the CD cover.
Cast enough resin details, clean them up with some light triming and filing and you can start applying them to the basic wall. It’s often worth casting a few extra parts and storing them for later re-molding (if your original mold has perished from the resin casting), or for use in creating new master pieces.
Here’s the finished master for the 15mm facade. You can see I’ve applied a set of the cast resin pillars and added the roof bracket details as well. Two resin pillars were cut down to make the smaller pillars flanking the top window. The rest of the building detailing has been added using a variety of thicknesses of plastic card cut into strips. This is where the faded pen guide lines the basic wall picked during casting come in handy to keep everything fairly straight. It’s worth taking the time to make sure everything is straight because you want to cast a set of these. For example several of the pillars were glued down and then pried up and reseated to get them straight.
Unfortunately I can see several parts of this facade that are crooked, can you spot them? The bottom left pillar is crooked, the middle row far left window isn’t straight and some of the plastic card trim has a noticeable bend in it. However chances are you won’t notice these issues once the buildings are on the gaming table and you’re standing 2-3 feet away from them.
Also take some time to make sure everything is well sealed. You can see above I’ve used a grey epoxy resin to seal the tops and bottoms of the resin pillars against the plastic card strips. I’ve also brushed on a water based DIY gap filler product to seal the gaps around the resin window frames and seat them into the basic wall more smoothly. This step is important because you want to get a clean mold of the whole facade, and having gaps between parts will allow the RTV to sneak behind details, leaving you with some fiddly mold trimming to do.
In the final post, I’ll cover molding, casting and creating terrain with the complete 15mm facade.