I've been mulling over making a Spider-Man shell mask to go under my Zentai Zone suit which I have recently purchased. The following is a process which I think will give me a satisfactory and low cost result.
Make a face mould using Plaster of Paris bandages. Do this in two parts, front and back of head, ensuring there is some overlap to the two sections. Use Clingfilm/bald cap/swimming hat to cover your hair. Apply a thin layer of Vaseline to the face as a release agent. Work the bandages so that they are tight on all parts of the face. Ensure you leave the nostrils clear.
Do the front of the face first, wait until the bandages have set and carefully lift from the face. Repeat for the back of the head. Use three or four layers of bandages.
When both are fully set, fit the front and back onto your head and use a marker pen to draw a line onto the cast where the overlap occurs.
Cut away the excess so that you have a good fit of the two halves. Make good any irregularities on the inside of the casts with plaster or clay.
When you are ready to make the foam cast, use duct tape, string or rubber bands to hold the two pieces together securely. Perhaps use a small bit of plaster inside on the join line to minimise seepage. But do make sure it is smoothed out and fully dry before proceeding. Smear the inside of the plaster cast with a thin layer of Vaseline to act as a release agent.
Mix up the two part polyurethane foam and slowly pour it into the cast. Leave it upended, allowing sufficient time for the foam to expand out of the neck hole and fully cure.
Once this is done, remove the plaster and smooth out any discrepancies in the foam cast. Where the foam has expanded past the neck line, cut it flat and level so it can stand up properly.
Using the foam cast, sculpt your face shell onto it with non-drying clay or plasticine. Work it until you have the desired shape. Work in some keying locations to the cast. Coat the clay with a thin layer of Vaseline as a release agent.
Use Plaster of Paris bandages to create the negative of the face shell, working up to the keying points on the head cast. Once this sets, carefully lift it from the clay and clean it up.
Carefully remove the face shell clay from the cast, leaving the location parts in place on the foam cast. Ensure every bit of clay is removed.
Coat both the face shell negative and foam cast with a thin layer of Vaseline to act as a release agent.
Using either liquid latex or silicone mould, carefully pour enough of it into the face shell negative and then press the foam cast into the liquid until the location sections meet where they need to. You want the casting liquid to come out a little past the edge of the face shell once the foam cast is pressed into final position.
Leave this to dry out as long as is required depending on the mould material being used.
When ready, remove the face shell and carefully peel off the latex/silicone face shell. Clean off the foam cast as it can be used for other projects.
Cut out eye holes, along with nose and mouth holes in your face shell mould.
With luck and a following wind, you should have a snug fitting and flexible Spider-Man face shell to use under your mask.
Any thoughts?