vOnly the truly worthy can wield the power of a god. That definitely includes award-winning cosplayer Pepper Monster, a.k.a. Sarah Maefs. For our latest episode of Cos/Play, Maefs breaks down how to build the newest iconic weapon from Avengers: Infinity War, Thor’s Stormbreaker. We also learn how Maefs made her first cosplay out of t-shirts, and why she got Mjölnir tattooed on her arm. Check it out!
How to Make Thor’s Stormbreaker from Avengers: Infinity War
10mm black foam
2/4mm black foam
PVC pipe (one 12-inch piece, one 24-inch)
Paint (black, two shades silver, two shades brown)
Rotary tool or belt sander
Downloadable Stormbreaker Patterns PDF
Instructions (available as PDF):
Phase One: The Hammer
1. Print out the pattern (as seen above).
2. Cut out and tape axe pieces A1 and A2 together to make one large pattern piece.
3. Place pattern pieces on black foam and cut each piece out carefully.
*Pro Tip: Only cut out the pieces you are immediately about to work with. You may need to enlarge or cut down some pieces to fit as you assemble your weapon. This will also prevent the misplacement or loss of small pieces of foam. Label everything with a sharpie to be safe.
4. Starting with the hammer end edges in the 10mm foam, pattern piece C, bevel the inside long edges to a 45-degree angle with a very sharp utility knife, a rotary tool, or a belt sander.
5. Wipe away all dust from your foam surface and use super glue on the shorter ends of all four pieces C to the four sides of piece B (square hammer end in 10mm foam). Set aside.
6. Cut out two pieces each of E and F. With a sharp utility knife, make shallow cuts into the surface, following the scoring lines on the pattern, and expand the lines using the heat from a heat gun run slowly over the surface, to create defined detail lines. On pieces F, carefully cut a V-shaped trench out of the length of the foam. Be careful to not cut more than halfway through the foam. Repeat on opposite side with E and F.
7. Bend the foam to close the trench and super glue it closed. This will create a nearly 90-degree angle in your piece. Use tape to hold the fold in place while the glue dries, if necessary.
8. Bevel the long sides of all four pieces of pattern piece D, at a 45-degree angle (just like with pieces C) and remove all dust. Set aside.
9. Super glue the wider end of pattern pieces E and F to the longer side of pattern pieces C, making sure to have pieces F (sides) across from each other, and E (top and bottom) across from each other.
10. Super glue your long beveled edges of pieces D to the long sides of pieces E and F, up to the angle you created at the end of the pieces. There will be an excess length of foam. Do not glue it.
11. Using sharp scissors, cut the excess length of foam of pieces D into a triangular point and thin the foam down by half, removing from the underside of the piece, to allow for the foam to bend and fit into the gap at the end of the hammer. Glue in place.
12. Cut out piece G from foam, score in detail lines with your blade, spread them with your heat gun, and super glue the narrow ends of piece G to the inside of the square opening at the narrower end of your hammer. These form the base to which your hammer attaches to the handle.
13. It’s time to close the four corners of your hammer. Pattern piece O is a “cut to fit” piece. Use tape and a sharpie to tape over the opening and trace the size and shape of your gap. Cut each corner to the size of the pattern you make off your personal hammer. Use your blade to bevel the four corner sides, so they narrow in the wedge shape to plug into your hole snuggly. Glue in place.
14. Use this time to clean up your seams. Glue any gaps, sand any ridges, and if you need to patch stubborn gaps, use Kwikseal (paintable silicon sealer) to patch any goofs.
*Pro tip: Use water on your fingertip to smooth the Kwikseal.
Phase Two: The Axe
15. Cut out pieces A1/A2 from foam and glue together.
16. Bevel the axe blade’s curved edge, to create your mock-cutting-edge. Work slowly to evenly remove the foam.
17. Following the pattern, score your details into the surface of your axe head using a sharp blade and shallow cut. Use your heat gun to spread the lines open just like on the hammer end.
18. Cut out pieces J (2/4mm foam). Cutting very lightly into the foam with your sharp blade, score in your details from the pattern.
19. Super glue down pieces J onto your axe head, aligning all your details.
20. Returning to the hammer end. Cut out pieces B2 (2/4mm foam). Score with a sharp blade the smaller inner circle, and use your heat gun to spread the detail. Glue down onto the center of piece B.
21. Cut out pattern pieces H, and I, and connect them end to end with tape, adding a one-inch length between the two pieces to accommodate the corners of your hammer.
22. Line up your piece H/I onto the hammer side, and glue down with your adhesive of choice. The detail should line up with the seam of your hammer, covering any imperfections you may be concerned with. Set aside.
Phase Three: The Handle
23. Grab a 24-inch length of PVC pipe, and heat the lower midsection with your heat gun slowly. The pipe will begin to become flexible. Careful so as to not burn yourself, bend your PVC pipe to curve slightly. Set aside to cool.
24. Glue a 12-inch piece of PVC to the connector, disabling the junction.
25. Super glue your axe head to the 12-inch piece of PVC, right in the center so that you have an even length of PVC both above and below your axe. Stabilize and let dry.
26. Once the axe is stable, glue the center of your hammer base to the PVC pipe opposite the axe head, with even amounts of PVC pipe above and below the hammer base. Stabilize and let dry.
27. Once the hammer is stable, cut out pieces K. Score in and spread with heat the details.
28. Glue pieces K to the front and back of the axe/hammer head, covering the PVC pipe. The base of the axe head will be sandwiched between pieces K, which will help stabilize it even more.
29. Cut out pieces L and bevel the long edges. Super glue your beveled edge the base of your hammer, and flat against piece K, so as to create a slope from the base of the Hammer, to the handle.
30. Cut out pieces M. Bevel the two long sides of the triangle, so as to close off your gap at the top of piece L and K.
31. Cut out pieces N, cutting to fit your gap in pieces K. Glue pieces N at the top of the hammer handle, in the right and left gaps between pieces K, hiding the upper portion of your PVC pipe. Cut to fit piece P, to fill the square gap at the top of your hammer handle.
32. Cut to fit any additional foam pieces needed to close off the gaps in your handle around the base. Your Groot Growth of the handle will cover most of these gaps, but filling them will give a better, finished look.
Phase Four: Detailing
32. Cut a long strip of 10mm foam and wrap it around the exposed length of PVC pipe at the base of your Hammer/Axe. Glue in place and cut or sand away excess foam from the seam.
33. Cut a long strip of 10mm foam and wrap it around the 24inch piece of curved PVC foam, leaving the appropriate gap at the top of the pipe so it can connect flush with your upper piece of PVC. Cut or sand away excess foam from the seam.
34. Attach the handle to the Axe/Hammer together at their PVC pipe junction. The curve in the handle should bow out towards the axe side of your hammer.
35. Using the sanding drum attachment on your rotary tool on a low-speed setting, or another sander, carve into your foam handle a wooden texture. Long irregular lines, creating knots, blemishes, and winding vine texture both above and below the juncture.
36. Cut two 24-inch or more lengths of 10mm foam, in an irregular but roughly inch to an inch and a half strips. Round their edges and bevel the same wood grain into these pieces, so that they match your Groot Growth on your handle.
37. Super glue your two strips of 10mm foam that now look like vines, in a crisscrossing X shape on the front and back of your hammer/axe head, and down onto the handle but ending above your juncture.
38. Using your sanding tool of choice, blend your crisscrossing vines into your Groot Growth handle.
39. Cut three wedge-shaped pieces of 10-mm foam roughly 4-inches long, and glue together like a sandwich. Use your sanding drum on your rotary tool to round your edges and blend the pieces together to make one block of foam.
40. Glue your wedge to the bottom of your Groot Growth handle, and once dry and stable, sand the wedge to blend into the handle, adding the wood grain into the base and flowing it up into the handle.
41. Cut out piece Q, score and spread with heat the detail, and glue to the underside of the axe head, tapering off towards the Groot Growth handle.
42. If you plan to use a heat knife or puffy paint to apply your rune details to your hammer, do this now. If not, paint them on at the end.
43. Wipe down the entire hammer to remove all dust. A damp cloth will help get the dust out of the crevices. Allow to fully dry.
Phase Five: Painting
44. Following the instructions on the can, plastidip spray your whole hammer, at least two layers, to seal the foam, making your new prop more durable and ready for paint.
45. Once dry, you can paint! Light and dark silver for your hammer and axe head. Light and dark brown for the handle. Dry brush the browns onto the high points of the handle, allowing the black plastidip to serve as your shading, creating a natural depth on your wood.
46. Use a small paintbrush to apply black into all your scored-in details of your Hammer/Axe. If you are painting your rune details, do so now. Use a mixture of the silvers and black to shade your hammer/axe to your liking.
47. Seal your new fully painted hammer with a clear matte finish spray to prevent paint transfer and add durability to your most precious prop.
48. Use a long length of leather twine to wind around your hammer’s Groot Growth handle. Wrap around above the junction, and separately below, so that your hammer can come apart for travel purposes, but the wrapping disguising the seam. Wrap another long length at the lower end of the handle, covering any visible seam where your wedges bottom base attached to your handle.
And there you have it... Stormbreaker!