This helmet was made from cardboard following an instructable by Honus.
Step 1: Materials
Cardboard ~ not the corrugated stuff unless you want it to look crappy I used the backs of some desktop calendars...the big ones 42 x 64
Glue ~ Any kind will work as long as you seal it before resining or painting. I use white glue and hot glue The white glue is for smaller details, and the hot glue is for big stuff or stuff u don't want to hold for a long time while the glue sets.
Clamps ~ Small clamps for holding glued pieces together Bulldog clips or clothespins will work too.
Sculpting medium ~ I used wallboard joint compound because thats what i had on hand. You can have better results if you use bondo or some other medium.
Pattern ~ Don't just throw something together. Make a plan! There is a paper modeling program called Pepakura that is very useful if you want to make a prop from a 3d file. Click here to get it
Sharp Knife ~ Xacto knife or something similar with brand new blades (blades will get worn out quickly cutting cardboard)
Sandpaper ~ For sanding...duh
Paint ~ O.o
Greeblies ~ Random junk to give it character
Step 2: Building
You can also fiberglass the inside for strength, but I will not go into that, because it was not necessary for what I did.
The result should begin to look something like this.
Step 3: Getting rid of gaps and cracks
Smear some stuff into the cracks and gaps to make it all smooth. You may also want to build up corners to make them rounded. It will look crappy and messy at this point, so don't get discouraged.
Get the sandpaper and sand down the bondo or whatever. It will still look messy, so you will need to prime it to see if there are any more gaps cracks, or divits.
Step 4: Painting
I use Triple thick acrylic sealer. I got it from the paint section and it comes in a spraycan. A little goes a long way, so spray light coats one at a time.
Now, you should be ready to paint.
Now you can add effects and greebles (greebles are misc. doodads that make it look more interesting)
After it is all painted you will need to seal it again. Depending on how rugged you want it, I would add 3-5 coats of sealer. (different brands give different results, so check the label).
Step 5: That's it!
Let me know if this is useful.
Below are other props I have made in this manner.
I would like to thank Honus for his ingenuity and I also claim no ownership of the patterns used to make these props.
These cost me no money whatsoever, and all materials were stuff I had on hand.