So, while I was trying to make a full moon, I discovered how to make
DIY Organs and Intestines for your
Zombie Halloween Party!
This project is two-fold. First you'll see how to make a 'disc of intestines' and I'll also show you how to create internal organs using a similar process.
Balloons: Red, Blue, or White, but anything you have around will work.
String: Ribbon can also be used, but rough string or twine gives that 'hasty home surgery' look.
Scissors: Junky ones. Great opportunity to use "throw away" dollar store scissors, cause you might have to pitch them.
Spray Paint: Red, Blue, Black, Silver, Gray, or any combo of those. Glossy Preferred.
Spritz Bottle: Filled with water.
Expanding Foam Insulation: Use leftovers after an Autumn Weather proofing project, or buy a can.
Round Mold: I used a section of cardboard tube originally intended for concrete footings. (You can find it near the concrete in a Home Improvement store. $9) We already had the tube at home for a costume, so I cut off a hunk, but really anything would work. See notes below.
Step 1: Gather Materials
The spray foam grows like The Blob, and sticks to anything in sight, so be prepped. Cut several lengths of string to tie off the balloons, set the mold of your choosing out on some scrap paper, and wear gloves. Be sure to follow all safety instructions on the foam, but most importantly, USE GLOVES - this stuff will NOT wash off your hands for several days. You can use acetone to clean up sticky scissors, but after it's dry, it's a lost cause.
Step 2. Intestine Mold
As I mentioned I used a short length of LARGE cardboard tube from the concrete isle in the hardware store. The inside is waxy, so after the foam dried I was able to remove it from the form. If your form is NOT waxy be sure to line it with a layer of paper or cling wrap, etc. If you are boldly using a spring form pan for this task - line it a zillion times! You can create your own amorphous shape from cardboard for a more imperfect organic look. (Still needs to be lined so it's not stuck to the form forever.) Set your form on a sheet of scrap paper (newspaper) and begin to fill the mold using the straw provided with the foam. As you fill the form, think like an intestine. Circular thin lines of foam give a great look. Remember, this Blob will 'grow' as it's exposed to air, start with thin lines. When you lines have grown to your desired thickness you can mist the foam with a bit of water to stop it's "growth". (Image below.)
Step 3: Organ Forms
The basic goal is to fill a balloon with foam, like you would fill a water balloon. Fill the balloon using the straw provided with the spray foam to about 2/3 to 3/4 of the ultimate desired organ size. Remember, variety in size and shape helps things to look natural. Slide the balloon on the straw and loosely tie a basic overhand knot around the mouth of the balloon. (Hint: That's just the very first part of tying your shoes, before you make the bunny ears. :) Having the knot in place before you press the trigger really helps for an easy tie-off once the Blob starts growing. Fill the balloon with foam ALLOWING THE GAS TO ESCAPE as much as possible, but containing the foam. Slide the balloon off the straw and tie it off - TIGHT!
Keep an eye on this stuff - seriously. You think it's done growing and leave it alone and you come back and it has doubled in size. Once it's grown to the size/shape you like, spritz with water to slow growth. The foam in the balloons will dry MUCH more slowly then that in the open form. I assume that's a lack of oxygen situation. After about 2-3 hours you will feel that it has started to firm up, but had not set hard. When that happens, WHILE THE BALLOONS ARE STILL PLIABLE proceed to the next step.
Step Five: Cut the Organs
Using CHEAP scissors, cut a slit in each 'organ' and allow some of the foam to ooze out. (It's SO HALLOWEEN-Y to do!) If you want more ooze, cut a larger slit, if you want to slow the growth, spritz with water. I found that slits about 1" long allowed enough flow to get nice "lumps" but not SO much ooze that the balloon emptied or the lumps left the balloon all together. Getting nice lumpy orbs is very much a surface tension thing. Lots of factors (temp, dry time, humidity, etc) probably play a roll in this, so play it by ear.
Step 6: Paint
Layering paint is the trick here. Lots of DEEP red tones (think Cranberry not Barn red) and mix in some darker tones. I used deep blue, but black or mahogany would work well too. For the intestines I started with a layer of silver (I was TRYING to make a moon - FAIL!) and that added some interesting depth. I layered the colors while the paint was still wet which allowed for nice blend and bleed among the layers of color. You can play with it. The best part is that pesky spray paint drip marks DON'T MATTER! They just look like dripping blood or veins, etc. Gloss gives them a nice wet look, achievable with glossy paint, or a high gloss modge-podge finish over the paint.
Step 7: Display
In the photos below I layered my organs in a shallow dish with blue glass vase filler (dollar store) so they looked like they were sitting on ice. I've about hit my gore limit with the organ's themselves, but you gory Halloween types could use fake blood in your display to amp up the yuck factor. I happen to have a Mad Scientist's laboratory display so I'll slip a few in apothecary jars as well.
For the intestines, I think setting them on a cake stand with a slice cut out at a zombie party would be SUPER yucky cool, but be sure you guests don't eat your fabulous new props!
PS: Failures: The intestines were a failed moon attempt. I was hoping the foam would create a big mushroom over the form. It was a VERY damp rainy day when I did this, so the growth was a bit inhibited I think - Could work in the future. The intestines were actually failed attempts at cheap ghost heads (that would save me a trip to the craft store) - I didn't think through that the foam doesn't GROW when not exposed to air (ie: in a balloon) so my anticipated big round foam heads turned out to be limp balloons. After a couple of hours I got tired of waiting so I cut into one to see what the holdup was and VOILA. :)