Clay, Sculpt, Mold, Noob?

T

Thegreatiandi

New Member
Hello all. I'm just now getting into clay sculpting... something I've always wanted to try. I went ahead and. Ordered my monster clay kit, and now I've been sculpting on my " ed head " bust ( nothing as cool as anything I've seen on this site sadly ).

So something I've always wondered was, how do you, after you have a sculpture that you are satisfied with, make this plaster mold? I've always wondered that. As an avid watcher of face off, thats one thing that's glazed over rather quickly. Pardon my ignorance here, but it just looks like a bunch of hemp or hay or something.... mixed with some kind of cement. I know I'm wrong, but that's the look. Even on my other favorite show, Making Monsters, they never go over how the plaster mold is created. Jordu just makes something amazing, then a plaster is poured in about 25 seconds, and bam! I have gathered that you must create some sort of shim to separate two halves...but even with this, how do you then fill this with foam to create a sculpted head..?

So hopefully I have explained properly what I'm looking for help with.

1. After you finish your mold, how to prep for the next step. How do you prepare your sculpture? Is the clay ruined after this?

2. How to create a mold. What is needed for this? materials? Skills?

3. After you have pulled your sculpture from the mold, how do you use the plaster mold for creating your foam head/arm/etc? What do you fill this with? It seems like you use foam of some sort...then after you pull this, there is your item.. ready to paint.

I really appreciate any help guys. My little one wants me to make monster masks and fail monster heads for Halloween... and all I have done is two horrible monster heads, and stalled out. I would love to move forward, and all of your help, will help this noobie move forward.

Thanks again!
 
ChickenHaunt said:
I cannot claim this is an excellent example, but here's a walkthrough of how I molded a sculpture for a latex mask once: http://chickenhaunt.blogspot.com/2014/01/moldmaking-tutorial-for-latex-masks.html
Click to expand...


This is a very great example! I'd read through that a few times to get all the basics. If you have any further questions I'm sure the board will be happy to help. :)

I'd only suggest two changes from that.

First, I wouldn't recommend using an acrylic binder in the stone. The only time I ever suggest using it is doing repairs to old molds to help the stone stick. It seems to make the stone weaker and it's latex absorption is inhibited slightly. (If you're making a latex mask of course, if you're running foam latex or silicone it is probably fine.)

Second, before covering the mold with a bag, spray it down very thoroughly with water. This should be done as soon as you see the mold start to steam from the exotherm.

My friend Rob Freitas explains it better than I do, but the jist of it is Ultracal is an "Alpha" gypsum, which means if you add water back in during the calcifyng process it cures to a much harder stone. If you've done it right you'll have an olive green stone color instead of white/grey.

Everything else in there seems to be pretty spot on.

Stone mold making is a complete art form in itself, and it will take a lot of trial and error. There are certain things you can't understand through text.. you just need to feel out the material to really understand it. Don't be afraid to mess up. Most of all... Never. Ever. Forget pry points. :)
 
I second the Stan Winston videos - I learned more from them than I did in University!
I didn't know that by adding water back into the process would turn the stone an olive-green? I am eager to try that, maybe that is why I sometimes have problems of hairline fractures? Thanks for that knowledge Mr Mold Maker.
 
cunningham said:
I second the Stan Winston videos - I learned more from them than I did in University!
I didn't know that by adding water back into the process would turn the stone an olive-green? I am eager to try that, maybe that is why I sometimes have problems of hairline fractures? Thanks for that knowledge Mr Mold Maker.
Click to expand...

Yep. Apparently it's an old concrete workers trick.

Because Alpha gypsums contain Portland Cement this trick works.. spraying it down and bagging it adds heat during the calcifying of the stone and that's what makes it so hard.. It also turns it into the olive color.

Back in the day you'd have to make stone molds that could last through 50+ foam latex runs and a lot of great knowledge has come out of and been passed down from those times. Glad to share some of it. :)
 
Mr Mold Maker said:
If you've done it right you'll have an olive green stone color instead of white/grey.

Stone mold making is a complete art form in itself, and it will take a lot of trial and error. There are certain things you can't understand through text.. you just need to feel out the material to really understand it. Don't be afraid to mess up. Most of all... Never. Ever. Forget pry points. :)
Click to expand...

Ha, Freitas told me about the plastic, too! I find also that having a high burlap to stone ratio helps with that same water retention thing, giving the darker color. It also keeps your weight down. The mold pictured is way too thick and heavy to be practical to me. The other change I'd make is I prefer to use epoxy parfilm as the release.

That last part is key. Dive in and mess up. If you pay attention to why things are and aren't working, you'll learn everything you need to know.

Hey, I know Gary! Didn't realize he had a video. I haven't seen his video, but he knows his stuff and is in demand, so I'd recommend that.
 
those videos are great, and there is not much to add, but here's $0.02 worth of free advice to add:

1. always mark the seam line with a Sharpie, so when half the sculpture is buried in clay, you know where the line is. I see Gary Yee do this while the sculpt is vertical, and then he lays it down to start the dividing wall. I believe you will get better results by laying the sculpt down first (being sure it is properly supported from underneath) and then use a square to locate the outer most edge of the sculpt. That edge can change depending on its resting position, so don't be afraid to adjust the resting position for symmetry.

I found this picture to clarify: clone6_case_mold_02.jpg You see that I am marking the base, and not the sculpt, but same principle.
 
For your first question i assume after your mold you expect the next step to be casting.if you are casting silicone in a stone mold you dont need a mold release.because silicone only sticks to silicone.but if you are casting something else a mold release like mann ease release would be necessary amd helpful.as for your sculpture ,i reccomend spraying it with 2 coats of krylon crystal clear spray paint to seal the sculpture.as for salvaging the clay after making the mold water based clay will be harder to salvage because it will sometimes dry and crack.but oil based clay will be very easily removed from the mold.for your second question for a normal two part stone mold you need a good hard gypsum like crystacal r,hydrocal or ultracal.first you need to make a clay separating wall this is just a thick strip of clay applyed to the side of the sculpture separating it in half ,then poke indents on one side of the walll,these will help the two halfs lock together.then mix up a thin batch of plaster and paint it on the front half of your sculpture,this is called a splash or beauty coat and it picks up fine details,then mix up a thick batch and slap it on your mold.do about another two of these coats.then you can make athick batch and dip burlap strips in it and apply to your sculpture.do another thick coat and smooth it down with a rubber kidney(a kidney shaped piece of rubber used to smooth things).remove the clay wall, Before you Repeat everything i have said for the back .melt some petroleum jelly in the microwave to a liquid state and paint this on the front half of the mold.after you repeat everything for the back separate the halfs with a hammer and a few screw drivers.as for the foam casting i reccommend polyurethane two part expanding foam.you just mix the two parts together in a small batch and pour it in your mold.then it expands and fills the whole mold.then you would take the mold off and there you have it a foam head.hope this helps
 
Mr Mold Maker said:
Yep. Apparently it's an old concrete workers trick.

Because Alpha gypsums contain Portland Cement this trick works.. spraying it down and bagging it adds heat during the calcifying of the stone and that's what makes it so hard.. It also turns it into the olive color.

Back in the day you'd have to make stone molds that could last through 50+ foam latex runs and a lot of great knowledge has come out of and been passed down from those times. Glad to share some of it. :)
Click to expand...

Great info in here, I had no idea about spraying and bagging.


What kind of mold release would you guys use on the sculpture before molding if you're going to be casting latex?
 
This thread is more than 8 years old.

Your message may be considered spam for the following reasons:

  1. This thread hasn't been active in some time. A new post in this thread might not contribute constructively to this discussion after so long.
If you wish to reply despite these issues, check the box below before replying.
Be aware that malicious compliance may result in more severe penalties.

Similar threads

Antonis13
Can I use low fire ceramic clay to sculpt masks? (Not high.)
Replies
5
Views
561
udog
udog
Egon Spengler
First attempt at sculpting with monster clay? Any advice?
Replies
2
Views
577
animator
animator
ERen89
Silicone mold options
Replies
19
Views
1,397
DarkHelmet
DarkHelmet
Egon Spengler
Tiny black dots in monster clay medium. Is this normal??
Replies
2
Views
371
DarkHelmet
DarkHelmet
Scream 31
I have no idea how to make a master mold
Replies
6
Views
678
JRFerreri
JRFerreri
Back
Top