I made this hammer for Elf Fantasy Fair, for my dwarf costume, but it can also be used for a Halloween costume, of course. It's pretty huge, but since it's made mostly from styrofoam, it's lighter than you would expect. I carried it around all day, and it was doable.

The materials you need:
- Styrofoam slabs, 2 cm thick
- PVC tube, a coupler and T-section
- PVC glue
- Hot wire cutter
- Acrylic resin (2-component system)
- Felt, black and blue
- Thin cork sheet (for wrapping the handle)
- All purpose glue
- Liquid nails
- Acrylic paint

Step 1: Getting Started

The hammer is made by glueing pieces of styrofoam together, and then coating it with acrylic resin. I used acrylic resin because this is water based and doesn't damage the styrofoam. For strength, the hammer head is built around a section of PVC pipe that is attached to the handle (wich is also made from PVC pipe).

Cutting the styrofoam is done with a hot wire cutter. This is a perfect tool for cutting styrofoam without making a huge mess. Mine can be powered by batteries or an external power supply. I have an adjustable lab power supply, and this is the perfect solution for using with a hotwire cutter, because it gives you a bit of control over the temperature.

I glued everything together with liquid nails. Make sure it works on polystyrene, of course!

Step 2: Coating

The next step is coating the styrofoam construction with acrylic resin, to give it a hard and smooth surface. The resin comes as a two component system: a powder and a milky liquid. It's water based, doesn't give off any noxious fumes and works perfectly on styrofoam. They are mixed in a 1/2.5 ratio, and then you have about fifteen minutes to apply it. It takes a lot longer to harden completely, but after fifteen minutes it will have thickened too much to work with it. This means, always prepare small amounts at a time!
I found this stuff not so easy to work with. You have to work pretty fast, and it's messy stuff. I put two layers on the hammer (using a paintbrush). The surface wasn't as smooth as I had hoped, but as it turned out later, this wasn't a bad thing at all!

Step 3: Painting

After the hammer head was coated with acrylic resin, it was time to paint it. I mixed up a batch of dark gray paint with a hint of blue, and started painting away. The entire head is painted gray, with the exception of the two deep ridges, wich are painted gold. To break up the even gray color, I drybrushed some black and white on it using a sponge, to the surface has darker and lighter spots. And finally, I drybrushed a thin layer of silver paint on the entire surface to give it a metallic look. Combined with the uneven surface (wich wasn't really my intention), it looked a lot like cast iron!

Step 4: The Handle

The handle is made from a section of PVC pipe. The bottom half is wrapped in felt (black and blue, in a weave pattern), and the upper half in thin cork. I also made an endpiece, much in the same way as I made the rest of the hammer. The handle connects to the PVC tube that's inside the hammer. After glueing it together, the connection is covered with another piece of cork sheet, and the hammer is finished!