Making a composite material from ABS slurry

Since I do a fair bit of 3D-printing, there’s always plenty of scrap ABS available. Some of the scraps go into the acetone / ABS slurry that I use to coat the build platform before each print, but there’s still plenty more to go around.

So, this got me thinking: “If I make something out paper, from a pepakura design or something, can I use ABS slurry instead of a resin to turn the paper into a composite material?”

TL;DR: No, it doesn’t really work.

A slightly longer explanation: It works, a bit, kind of. To test this new revolutionary material that I had just invented, I needed a pepakura project. I built a Captain America helmet from some design that I’ve already misplaced:

I added some cardboard bracing to make sure the paper helmet stayed in shape during the application of the slurry:

I then applied ABS slurry all over the inside of the helmet, and left it to set. This is what happened:

Once the braces were removed, things went from bad to worse:

It turns out that in addition to shrinking when cooling down, causing grey hairs to 3D printing enthusiasts everywhere, ABS also shrinks when drying after being applied as acetone slurry. The shape of the helmet is very stubbornly staying much like the last picture shows, despite attempts to bend it back into shape.

Now, it may be possible that if I applied the slurry on both sides of the helmet, the effects might have canceled each other out. Anyway I’m pretty sure that this particular project isn’t salvageable at this stage.

So, as a conclusion: Really not as great as I thought it might be. Some promise, not a complete waste of time, but I’m in no huge rush to conduct further experiments.

---

EDIT: A few days later, after looking at this sorry ass excuse for a project on my desk, I was faced with a choice: Either throw it away now, or see what could be salvaged by applying another layer of slurry on the outside. And, since I’m writing this, you already know what the decision was.

The slurry I had in the jar this time around was a lot more acetone and a lot less ABS when compared to the stuff I used the last time. It felt a lot more like painting with the slurry, which seemed to get absorbed into the paper much more readily, but of course it also ran off the helmet much easier, too.

The next day, when the acetone had evaporated, it was time to assess the results.

This is a bit more promising. Next, I guess I’ll need to see about finishing the piece with some sanding and a coat of paint. Stay tuned!