How To: Caulk a Bloody Brain Cap




Introduction: How To: Caulk a Bloody Brain Cap

About: Hi! I'm Jeromina Juan. Formerly paperplateandplane. Contest addict, earning my beloved kitchen and tech supplies one contest at a time.

Make and wear your own bloody brain cap using a couple of tubes of latex caulking and a fitted ball cap!

I wrote this project originally for Craft:
The project has also appeared in Make:

Fitted cap, without adjuster
Craft knife or seam ripper
Acrylic paint, red and black
Bowl, approximately same size as cap
Tall jar
Plastic bag
2 tubes of latex or acrylic caulking (not silicone)*, ivory or bone color
Caulking gun


Step 1: Remove the cap's brim by carefully ripping the seams with a craft knife or seam ripper.

Step 2: Place the cap on newspaper. Paint the cap with dark red paint (a mixture of red paint and a little bit of black paint). Let dry.

Step 3: On newspaper, create a work stand for your cap by placing a bowl upside down over a tall jar. Place a plastic bag over the bowl, and the cap over the plastic bag.

Step 4: With a craft knife, cut the tip of the caulking tube to have an opening approximately 1/2" in diameter. Load the tube into a caulking gun.

Step 5: Caulk convolutions on one half of the cap to create one hemisphere of the brain. Repeat on the second half of the cap.

Step 6: Let the caulking dry for approximately one to two hours until the surface loses tack. Wearing gloves, lightly press on the convolutions to slightly flatten the surface.

Step 7: Let the caulking cure for 24 hours.

Step 8: Once the caulking has cured, mix water with red paint and a little bit of black paint, to a thin, runny consistency. Use a brush to dab paint mixture onto the caulking, focusing on crevices. Apply a second coat if needed. Let dry.

Halloween Photos Challenge

Second Prize in the
Halloween Photos Challenge

Halloween Props Challenge

Participated in the
Halloween Props Challenge

1 Person Made This Project!


  • Raspberry Pi Contest

    Raspberry Pi Contest
  • Jewelry Challenge

    Jewelry Challenge
  • Knitting and Crochet Speed Challenge

    Knitting and Crochet Speed Challenge



2 years ago

It's always a challenge to find a Halloween costume my husband will wear, thank you!!!


6 years ago on Introduction

Um, is it possible to replace the baseball cap with some rounded foam core it create a model? And how would one go about making the inside of the brain with the caulking?


8 years ago on Introduction

I wonder if you can use a clear caulking and have LEDs embedded in the cap.


10 years ago on Introduction

I've used caulk for a couple projects with mixed results, one night wounds are ok but they tend to crack when drying and in other cases the project is super heavy for its size or the caulk didn't stick to the surface, it's still a go to material for tests though. Cool idea !

I love this cap! I couldn't tell it was caulking the first time I looked at it! To finish it off, is that just a bandage strip with red paint?