I'd like to start off by saying that I will never use the hot wire cutter for buildings ever again. The angle at which the wire is strung makes it next to impossible to judge what a 90 degree angle is with it. Sure, it's great for organic, natural terrain, but to achieve those solid edges that Human Imperial buildings require it just falls short. If I had a band saw or table saw I would certainly use that instead, but the best I have available is a sharp knife. The only problem with using a knife on pink foam is that sometimes the knife will stop cutting and start pulling bits of foam with it, damaging the straight edge that's being aimed for. With that said, here's what a hot wire cutter foam building looks like.
First, you'll want to have a plan as to what you want your building to look like. If you've followed me long enough, I'm sure you're expecting one of my little hand drawn sketches. For some reason the original sketch resulted in the building not ending up exactly as planned and the top roof didn't match the sides, so I reworked the sketch digitally so if you want to use my plans these should work. Maybe.
Since I play Warhammer 40000, that's what I've invested my time and money in and I don't have the luxury to system hop, my buildings have the intention of taking advantage of Warhammer 40000 rules. The precedent being the largest terrain piece should be 12" by 12", and I wanted the building to provide useful cover for armies like the Tau, so I decided to make a large enough structure to jump shoot jump from as well as hide tanks and troops. It even has large flat spaces for jump infantry to land on. With these things in mind, I mapped out this plan.
The next step is to actually transfer this idea onto 0.5" thick pink insulation foam. By now, you should know this is my favourite material. It's relatively strong and durable, which suits my needs. I want these terrain pieces to look good, but also be durable. I want them to be able to survive actual play, with players having a bad day being rough with them. Pink foam is fairly good for this. The only thing better would be actual plastic or resin terrain. I strongly recommend using a square to get 90 degree corners and straight edges.
Once you actually have your plan drawn out onto the pink foam, it's time to free those pieces from their solid sheet prison. If you're as crazy as I am and using a hot wire cutter, you may want to roughly hew the individual parts out before cutting at the actual edges. Even if you're not using the hot wire cutter, you may want to cut the pieces out before cutting them flush. This is why I left plenty of space between each piece on the sheet foam.
Now that those pieces are cut out, you'll need to stick them together to create some sort of building-like form. Do not use PVA glue, it will end up a messy nightmare, and it won't fill the gaps that result from the hot wire cutter's less than accurate cutting. Use some sort of adhesive material that will also fill the gaps as well as hold the parts together. For this project, I used Dap 3.0 Advanced All Purpose Sealant. It forms a rubbery bond and can be smoothed by watering your finger and smoothing where it escapes the bonding points. This stuff is gummy and smells something fierce, but it really holds pink foam together.
I left this for 24 hours. I returned to it and glued the bottom roof to the lower half of the building, then slid the upper back in place. I then applied glue to the top roof and fitted that in place. The top roof was supposed to just sit on top of the building like the bottom roof does, but for some reason the original measurements didn't add up. So I made some creative adjustments, cut some foam off and made it work as it is. I turned it onto its side again, put my weight boards back on and let it dry for another 24 hours.
Once all of this has been completed this will be the result. The hot wire cutter doesn't do well for straight edges and leaves gaps all over the place. The most obvious ones are on the sides where everyone can see. Some Polyfill will work to fill those gaps if some of them are especially displeasing. Just remember to not glue your building to the base; we want this to stay removable so that the ruins that we will build underneath can be displayed if and when the building gets destroyed midgame.
That's it for now, next time I will definitely be using a sharp knife instead of the hot wire cutter. I just need to draw up some new plans. August has been a busy month for me, but I've managed to wrangle up a bunch of interesting things for terrain. I'm going to keep the construction and decorating articles separate so that I can display many different end results. Hopefully you'll be inspired to make some terrain of your own, and as always I actually want to see it! Don't be afraid to link to your work in the comments. That is all.