I thought this might make a good first Instructable after the amazing reception it got at Spiders Nightclub's Halloween Party. I'd wanted to do something like this for a couple of years but never got around to it in time for previous Halloweens. It took a few days but most of the time was looking at shark pictures on Google and making little paper maquettes of the shark to try and work out scale and construction. I used an Action Man (GI Joe in US) doll to get human proportions but everything would be much easier if there were two people involved so you could measure up on a live model. By the way, I am very old so a trip to some old boxes in the attic dug up an Action Man of early 1970s vintage. I believe Action Man/GI Joe nowadays would only be useful for pattern making if you are a giant steroid-filled bodybuilder.
I would highly recommend getting a friend to help whenever you have to try the pieces on for fit, it'll save a lot of time. I'm the kind of person who visits instructables a lot and thinks that spending the week before Halloween building a large and impractical costume is a better idea than going out and talking to people so consequently I have no friends to help out.
All the proportions and patterns are designed to fit a skinny person like myself, not much of a meal for a shark! YMMV.
Step 1: Stuff you'll need
A large sheet of 1 inch thick grey foam rubber for the shark's back (or a white/pale one if you plan on spray painting it). You can get this from upholstery suppliers or online. In the UK it tends to be colour-coded by quality and the grey is a more expensive foam. I was lucky enough to find a poorly-cut sheet going cheap. Exact sheet size will be down to the size of shark required!
A large sheet of 1/2 inch thick white "Zotefoam" type material for the shark's belly.
A small sheet of 3/4 inch white "Zotefoam" type material for the shark's muzzle & teeth.
Zotefoam/Plastazote -type foam sheet is a semi-rigid polyethylene foam much stiffer than foam rubber. It's the kind of foam you find in camera and gun cases where a precisely-fitting recess is cut out to fit the item to be protected. It's also used industrially as flexible insulation board. If you hunt on Google you'll find suppliers on the web, it's light so not expensive to ship in large sheets. You could probably just about get away with some form of cardboard box material if you can't find/afford this foam. I happened to have a sheet lying around that I've known for years would come in useful one day...
Some 3/4 inch wide nylon webbing strap and plastic clip/buckle to make a belt.
Some 3/4 inch wide elastic and another plastic clip/buckle to make a leg strap and some hinges.
Gloss black self-adhesive signmakers' vinyl to make the shark's eye.
Ordinary A4/US Letter size office copier paper for the small, paper maquette sharks.
Large sheets of paper/cardboard for the full-size patterns. Anything you can draw on with a pen will be fine. I guess a cheap wallpaper (lining paper) roll would be fine, I had a large roll of 610mm wide plotter paper from my graphics work.
"Evo-Stik" -type impact adhesive. A kind of solvent-based flexible rubber glue. I think "Cow Gum" may be a simlar US equivalent but I'm not sure on this. You coat both surfaces with a stringy, messy, snot-like glue and then allow it to dry to the touch for 15 minutes or so before pressing the surface together for an instant (non-repositionable) bond.
A hot-melt glue gun is useful too.
Low-tack masking tape
Red, white and yellow artists' acrylic paint
Needle and thread to attach the buckles, you could get away with either of the glues and skip this but I like to know a costume won't let me down in a crowded nightclub where it'll get quite a beating.
1" wide self-adhesive strong velcro tape (white if possible).
Very sharp craft knife with lots of spare blades. IMPORTANT - don't skimp on new blades when cutting the soft foam. I used a snap-off blade boxcutter type of knife.
Scissors. Don't run with them.