Casting Helmets

Achille

New Hunter
Hey, I'm kinda new here (okay, really new here), but I guess I'll start off my posting career with a question.

I've been planning on making an Iron Man Costume For the upcoming Halloween. Kind of a short notice, I know, but I didn't get the idea until maybe a week ago. Anyways, I think I'm going to try to make the armour out of sintra, but I want the helmet to something more substantial.

I'm going to start making the sculpt as soon as I can get my sculptey clay. It's after that that I started to get confused in my planning process. I know that I have to make a mold (of course), but then I can't decide how to cast it, so I was wondering if anyone had any advice.

I want the helmet to be completely form fitting, and the method I was thinking of doing was casting the helmet in three seperate pieces (Front, back, and mask), then hinging the front and back together. If I do this, would it me a better idea to cast the front and back as one piece, then cut it in half, or would it be better to cast the pieces seperatly and then put them together? Please note that I do not have access to a vacuumtable, so I cannot make a mold using that method.

of course, I'm new to this, so if anyone has a better way to do this, please let me know.

Any input is appreciated, thanks!
 
Well, for a first mold, youll want to slush cast it.

This means make your full sculpt, then make a mold of the entire thing.

The mold will actually be two molds, a silicone mold, about half an inch thick all over to grab the details, and a 'mother' mold made of a hard resin, firberglass, plaster etc depending on how long you want this mold to last.

Once you have made your mold, and your mother mold, you remove your model, and pour in resin.

About a cup (1/2 of part a and part b)
and swirl it around.

it will cover a spot about 7 x 7 inches eash slush.

Once you have good coverage all over, you take it out of the mold, and do what you please with it.

Alternatively you could do both sides seperately, in a squish/compressiom mold, but thats much more complicated.

So, first order of business, go to smoothon, polytek and alumilite's websites and watch / read their tutorials. In your spare time of course:)

m2
 
Ah, I hadn't read about using a silicone mold and a mother mold, thanks for that! Your post really helped clear some things up.

After looking at the shape and design of the model again, I've decided to try to make it be able to go on in one piece, so that eliminates a good portion of the complexity. I also decided to make the gold mask out of the Sintra, so that makes it even simpler. Time to find the time to get started!
 
For slush casting you pour the silicone inside like its milk in your cereal bowl, then slush it around till it hardens, then do more, until you get good even covrage.

Now, if you have a mold without terrible undercuts on the INSIDE you can do a 2 piece squish mold. But things like a boba helmet are tough for that, because the cheeks dont like to come out.

Do a search on squish or compression mold.
 
Here's a pic of my iron man mold. It's a silicone sock mold with two part fiberglass mother mold. I slip cast with smooth cast roto with 5 layers. Hope it helps.

DSC01169resize.jpg
 
Le gasp! Thank you for explaining that pic! I had figured that the pink was the silicon, but I wasn't sure what the fiberglass mold was till now!

Is slip casting about the same as slush casting, or more similar to roto-casting? Or is it some other type of casting altogether? I'm trying to learn as much about casting and molding as I can. This is a ton more complex than I thought it had been, but that's not gonna scare me off.

Update on the helmet: Finally got some mesh to provide a base, and am starting on the clay as I type! Pics coming soon.
 
As promised, some pics (Cell phone quality, but still, there they are). Right now it's only the basic shape, and not very refined. But not bad for only an hour or two of work. I think I'm going to put finishing touches on the main helmet, then work more on the gold mask.

Does anyone have a good method for smoothing out oil based clay? I know for water based you wet your hand then blend, but I don't think that that'll work for oil based. Any suggestions?

0930082216.jpg


0930082216b.jpg
 
oil based - I love and hate this material in equal parts.
white spirit works for me. Heard some people working under heat lamps to keep it supple too. Last final smoothing refinement is with ur loop tool - again, and again, and again, and again.....

not sure if theres a better solution - I am kinda new with it too. Also considering if a water based air dried clay may have been better :(

Nate
 
I definitely think oil-based is better. I tried sculpting a hand out of water based clay, and it sucked. The clay never gets to the perfect amount of moist, always to dry or too wet.
I'm just gonna pick up a loop tool later on and take my time. Thanks for the advice.
 
3m citrus based cleaner sprayed on will soften the surface, use a stiff bristle brush to work the surface, then use alcohol to dry it back out, work it over again with a soft bristle brush. repeat til desired smoothness. Also try sponges and scotch brite pads. Good luck!
 
DangerRuss is a professional - so would take his advice seriously.

heres an excerpt of advice I got from Marverick118 on RPB - a top notch guy - when I started on oil based clay -

"clay is difficult to get smooth...You need a variety of tools...Kemper rake tools...These are the wire look tools you maight have seen in an arts department of the hobby stores and the like. They are wire loops with wire wrapped around them to form a varity of differnt sizes...you do multiple passes with these breaking the surface down, sprying or rubbing IPA alcohol on it if it's oil based. then repeating. Each ttime the size of the rake gets smaller...look at it like using differnt grades of sand paper...."

hope that helps Achilles.
thanks for heads up on water based. I went down oil based route based on info I read of DH2/SC. Wife mostly uses waters based for her stuff - migth play around with both and come to my own conclusion.

Nate
 
Quick little update.

First, I've completely restarted. The wire mesh was way to weak to support the clay. I did some searching and found a nice styrofoam head, and am now about 3/4 of the way done with the sculpting. However, since I used a styrofoam head, I don't think I'm going to be able to bake the clay without the styrofoam melting all over the oven. Does a sculpt have to be baked in order to make a mold? Or is there a way to protect the styrofoam from melting?

Thanks everyone for the advice and support, it's coming along so much better than it would be if I didn't know about this site!
 
No, the clay does not need to be baked. It should be sealed though. Whether you are using oil clay or water clay, several coats of sealer will do well.
 
Photo update: I'm actually farther along than this, but these are the most recent I have.

I've completed the mask and am almost done with the ear circles. My main problem is that whenever I try to attach the mask to the helmet, the clay is too heavy and makes the mask fall off. I'm just going to rubberband the mask to the helmet whenever I'm not working on it, that should keep it together. With any luck I'll be able to start making a mold in a week or so! :D

no mask.jpg


1004081909a.jpg
 
I would cast it in polystyrene instead of fiberglass, unless you have plenty of ventilation. Also, moldmaking is an artform all it's own. If this is your first time doing this sort of stuff, I would mold something, anything first. In art class they make you mold a simple brick, just so you can understand the basics of it. Depending on what you are casting with, you may need to make a cored mold, and that is pretty tricky stuff! Fortunately for me, my neighbor is a Dick Smith trained fx guy and I learned a ton of stuff from him.

For sculpting, I would watch Mark Alfrey's "Sculpting the Human Head" video before I even started. Much of it doesn't apply to what you're trying to do, but you can get a good idea of what each sculpting tool does and doesn't do.

Oh and this is my first post on this fantastic board!
Good luck man.
 

How I casted my 300 helmet

Going to be making a step by step video on molding here in about a week or so.
 
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