Twisted Metal; Tea lights can melt foam beams
WARNING: The following tutorial uses a sharp cutting blade and fire. It should only be done with adult supervision or by those who like to look fate in the eye and say, "Whatcha got big boy?"
Over on Facebook in the Diostructure group, a fellow by the name of Khalid used pink insulation foam to create I-beam girders and then held them over a tea light to melt and twist them into a destroyed look. Well, actually he was using them as weapons for Magneto, which just goes to show one of many uses for this idea. I tried to talk drbindy into doing it, but he was too busy 3D printing a staircase and banging out a dozen custom figures, or something boring like that. More importantly, we had more questions about how the girders were made than answers. Sure, I could have reached out and asked the guy, but where's the fun in that. I wanted to see if I could reverse engineer it.
Stuff you'll need
- Xacto knife (a hot knife for cutting foam also acceptable)
- Knife sharpener
- Insulation foam, preferably 1/4-1/2" thick
- Pen, mechanical pencil, or anything for making small circular indents/holes
- Foam glue (super glue eats styrofoam)
- Tea light
Step 1: Eyeballing it
If this was for a genuine diorama, I would have measured everything out, maybe penciled outlines, and used a hard sided ruler for cutting. Maybe I would have even used a hot knife for cutting the foam in a more uniform fashion. But this tutorial isn't to see if it is possible. Khalid already proved that it is. No, this is about seeing how hard/easy it is. Since these will be warped and twisted and ultimately "battle damaged" anyway, messy works in my favor.
So I eyeballed 1/4" and 1/2" width strips and cut them out of a 2" block of foam with the Xacto knife. I did both sizes to see which one I thought would work best for 4" figures. I mean, technically any size will work, but I want figures to be able to hold them as weapons. I used the block because that is what I had on hand, but starting off with a thinner insulation board from the beginning would be preferable for a project like this.
Helpful Tip: Due to the density of the foam and how it snags on a dull blade, you'll only get 4-5 clean cuts from here on out until the blade needs another couple of swipes on the sharpener.
Step 2: Stripping off the layers
This is the part where drbindy and I could not quite figure out, based on the pics, how the I-beam girders were created. Were the foam I-beams one solid piece dug out with a foam cutting tool or were the walls cut separately and glued back together. I opted for easy regardless of accuracy and went with cutting the walls and gluing them. I took the strips of foam and made 1/8" wide slivered layers. You need to be careful that the blade is cutting where you want it to on both sides of the beam.
Cutting 4 layers for a 3 walled beam might seem ridiculous, however, when slicing anything down this thin, it never hurts to have a spare. That ended up paying off for me as one of my cuts ended up being too thin because of pre-existing dents in the foam.
Step 3: Riveting results
This step is optional as it really comes down to preference whether to include the rivets or not. Steel beams are usually pressed from the liquid steel to be one solid piece and usually rivets are only used to reinforce or connect the beams together. Stylistically they look great, but you may want to look at some real life samples before deciding what will work best for your project.
Adding Rivets with, well, rivets
Hobby Link Japan sells a great set of 1/35 Nuts and Bolts. If accuracy is your thing, this is the way you'll want to go.
Adding Rivets with a pencil
However, if you are like me trying to do this quick and dirty, using a mechanical pencil is the way to go. While you can use any tool that leaves a hole or indent, I like the mechanical pencil for this because it leaves a raised center inside an indented circle. Plus it is a lot easier to poke the foam wherever I want the rivets to be. For this tutorial I kind of went overboard while still being somewhat realistic on one side of the top and bottom walls of the beam. I left the inside wall blank, but can always go back and adjust before painting.
Step 4: Here's glue in your "I"
You cannot use super glue on styrofoam. It eats right through it. The diorama builders tend to use Gorilla Glue or Loctite Power Grab or in some instances plain white glue. Because my wife happened to have some Scotch Clear Glue for her scrap booking crafts, I used that. As long as it is safe for foam and holds the strips together, it doesn't matter which you use. I put a thin line of glue on the inside of the bottom wall of my beam and then pressed the inside wall (the one without rivets) into it. The thickness of the glue compensated for any of my uneven cuts nicely. If you were to look at it from the top it would look like an upside down "T".
Then I did the same thing with the top wall of the girder, making sure my rivets were facing the outside.
Getting fancy with it
Since the foam is so easy to cut and shape you can get kind of fancy for detailing and make connector plates for the inner walls.
You can also get super duper fancy and do lattice girders for the inner walls by cutting out triangle shapes. Because of the next step, I wouldn't advise doing the outer walls this way.
Step 5: Candle in the Wind
BURN IT WITH FIRE! No, don't do that. In fact...
WARNING!: I cannot express to you just how quickly things can turn your foam into a pile of melted goop. So let me show you. This is a slow motion video I did on a test piece to see how far away I needed to hold the foam above the candle to manipulate it. While the video is 23 seconds long on youtube, it was only 3 seconds of filming time, and the actual melting took place in less than a second. You can actually hear me gasp at the :12 second mark as I saw how fast it was melting.
With that in mind, you want to hold the I-beam about 3-6 inches above the flame. Close to the heat, but not too close. How close is too close depends on the strength of the candle and the amount of heat it is putting off. So, all I can do is reassure you that you will find out very quickly how close is too close and to tell you to use a test piece first to find that sweet spot. Once you do find that sweet spot, start twisting and bending or otherwise manipulating and distorting your I-beam however you want it to look.
When I happened to melt a little too much on mine, I used that spot to bend and crinkle it down.
At this point, I was feeling pretty good. It wasn't that hard to do, looked cool, and didn't take up a lot of time or materials. I banged it out over the course of two nights. Mission Accomplished! However, I was left with a lingering question. Now what? Sure, with girders you could actually build something, a bridge, a construction zone. But what is someone supposed to do with damaged beams? Well, the short answer is whatever you want. It took longer for the glue to dry than it did to come up with this setup.
That's from a novice who just learned how to do it. Put this skill in the hands of a master like the aforementioned Khalid and you can master magnetism.