You may already own most of these materials and tools. I did. Listed below are what I used, preceded by headings of whether they were purchased, pre-owned, etc.
Plastic soldier helmet from the local thrift store - $5.00
Black PVC Foam Board (Sintra) - approx $4.00 -
bought at a local plastics supply house http://sintrapvc.com/
Cheap Puck light - $1.00
1 length PVC pipe - $0.98 for 10ft. (you won't use all of this)
2 PVC tees - $0.65 each
4 PVC elbows - $0.80 each
Soccer shin guards
Kids elbow and knee pads
Black Zip Ties
Hook and Loop tape with adhesive backing (i.e. Velcro with peel and stick back)
Black Turtleneck sweater
Black sweat pants
3 disposable plastic ground beef containers
1 disposable rotisserie chicken container
1 nylon web belt and plastic buckle (this was stapled to shipping a pallet, and was used for strapping)
Squeezable ketchup bottle lid
Honda Odyssey grille emblem
Packaging foam from a computer monitor box
Imagination (Most important tool)
Heat gun - you can use an oven or even a large pot with very hot water
Drill / Drill Bits
Hot melt glue gun / glue sticks
Black Spray Paint
Step 1: Collect your materials / Design around the objects you collected
I find that it is easier to design around items you have rather than the looking for an item that will fit your design. Keep an open mind. Rotate the objects and look at them from every angle to gain inspiration.
I drew several basic designs on a couple of sheets of paper and had my son choose the design he wanted.
Keep in mind the images might not properly depict the stages of the build in the instructions. For clarity's sake I am documenting this in a "supposed" chronological order, when in reality I was doing every part of the suit at the same time and was using the paint drying/glue curing times to work on other portions of the suit, as a result some sloppiness occurred, as is my nature. :(
Step 2: Making the Chest and Back Plate
I first traced out the shape of one of my son's T-Shirts so I could get an idea of the scale of the Chest Plate.
I went through a couple of iterations of chest plate shapes before I picked this shape. I then cut it out of the calendar paper, pressed it to my son's body making sure he had enough room around the neck area and that he had adequate movement in the arms and torso. I made sure to cut the pattern slightly above the waist so he could bend slightly at the waist.
I then transferred the shape of the pattern by tracing the pattern onto the the black PVC foam board using a silver Sharpie marker so it showed up better on the black background.
I used my band saw, but you can use a sturdy box cutter to cut through PVC foam board. You'll have to make several deep, repetitive cuts . Rotozip or Dremel type tools will make cleaner rounded corner cuts.
You might as well cut the Back Plate while you're at it. They're almost the same shape. The back plate 's nape does not need to extend as low as the Chest Plate's neckline. Look at any T-Shirt and you'll see what I mean.
Step 3: Chest Plate - Bend the PVC Foam Board to the desired shape
I used a heat gun on this job, but in the past have used boiling water or a warm oven to achieve the desired effect.
One thing about using the heat gun is that you only heat up the area that you are working on rather than the whole shape. The heat gun is actually the safest option IMHO.
I heated the area where the crease was to be and once the PVC Foam lost its stiffness I used the edge of the table as a straight edge and bent the piece to shape.
After all the bends were done I "eyeballed" the bends and re- heated and re-bent portions that needed rework. I had my son close by and constantly test fitted the piece to his body, making adjustments as needed.
Safety - Keep in mind the sheet may still be warm/hot. Do not lay this on exposed skin until it is comfortable enough to hold with your bare hand.
Alternative Costume idea: You could use PVC Foam board to make cool Roman Centurion type Chest Plates. You would have to make a simple mold out of household objects like bowls, cups, saucers, soap dishes, etc. Just use your imagination. Lay them face down on a table and use duct tape to hold them in a specific pattern. Warm the PVC Foam board in the oven and one flaccid move it quickly to the table and lay it on the arranged bowls and saucers. Using an oven mitt, you can carefully smooth the shape of faux stomach muscles on the warm PVC Foam Board.
Step 4: Combine Chest Plate/Back Plate
Once the shoulders portions meet at the top of the wearers shoulders drill holes on each plate for the zip tie hinge. I went overboard and planned to use 4 zip ties per shoulder so I drilled 8 holes per plate. Way overkill.
Insert the zip ties in the holes making sure the zip tie "buckle" is outside the suit. Do this for the comfort of the user. Leave about 1/4" or more slop/gap between the chest and back plate when you zip the hinge together. This is so you can adjust the fit later.
Step 5: Back Plate - Bending flaps and shoulders - cutting access holes
If you plan on gluing anything to the PVC Foam Board make sure you get the general gist of where you will be gluing these objects so you can plan on leaving those areas relatively flat for ease of gluing.
Once the final shape was achieved I got one of the ground beef containers and placed it on the Back Plate and cut a hole with a box knife about 2 inches smaller than the container. Rotozip or Dremel type tools will make cleaner rounded corner cuts.
Step 6: Complete majority of Chest Plate
I also attached the bottom of a Rotisserie Chicken container from the local deli as a makeshift "stomach muscle mass". I only used 1-1/2" of the bottom of the pan though because the pan was so tall. To achieve this I placed the container on its back, got a deck of cards, lay a Sharpie marker on top of the deck and rotated the pan while using the height of the deck of cards and the Sharpie to make a clean line all the way around the pan. I then used box cutters to cut the pan on the line.
I got some computer packing foam and cut it thick enough to fit inside the chicken pan to give the glue something to adhere to. I then hot glued the foam to the inside of the pan, then hot glued the opposite side of the foam in the pan to the Chest Plate right around the area where abdominal muscles would be. This happened so quick I forgot to take pictures.
Admired the look for a little while, then back to work.
Step 7: Complete Back Plate
I glued the meat tray to the Back Plate. This could be the Power Supply or Portable air supply....whatever. I wrapped some red tissue paper around the lens of a compact flashlight (its all I had - red cellophane would have been better). I then crammed the flashlight in the access hole on the back plate. Once turned on the light looked reminiscent of HAL's "eye" in 2001 a Space Odyssey.
Step 8: Make belt loops and add belt
Step 9: Embelish
I found an old Honda emblem in the garage and glued that on too. Sure the costume looked gaudy, but with all the lights and gleam he was sure to be noticed by passing motorists.
For the record I actually liked the plain black look better, but it looked out of place with the helmet.
Step 10: Make a matching candy bucket / Human DNA Transporter
1) I removed the corner flanges of the meat trays.
2) Attached the meat trays rims together with hot melt glue.
3) Using a table saw, I cut a slit down the center of a 3 foot section of PVC tube. I think I used 3/4" tube. I got the cheapest possible thin wall PVC tube.
4) I Cut 3 tubes the width of the meat trays, and 2 tubes the length of the meat trays.
5) I Cut slits in two of the PVC Elbows and 1/2 of both the Tees. (pictures will explain better.)
Step 11: Completing the candy carrier
2) Dry fit the 2 slitted elbows and 2 slitted tees. Once satisfied with the length of the pipes pull both elbows and tees off.
3) Clean each slitted elbow and tee. Once PVC glue is applied reattach them to the tubes. Apply glue to each fitting and attach before moving on to the next fitting. Do not apply glue to all 4 fittings and rush to get them all attached in time. You'll never make it.
4) Dry fit the last 2 elbows and 3 lengths of unslitted PVC Pipe to make a handle . Make any adjustment to lengths now.
5) Disassemble, clean glue and reattach.
Step 12: The completed outfit.
He was one happy kid!