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Me Crystal Skulls

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All you making your 3 axis skulls from that lindberg skull buy. May as well show you another thing I've been up to with mine.

Well, the first Crystal Skull, anyway. I got some smaller ones coming soon as well to go with it.

You'll have to forgive the fuzzyness, I didn't want to use flash to show how it refracts the light and couldn't find the tripod. And they didn't look quite so fuzzy on the camera's little screen.






More to follow soonish, but these take a while to set up. (a week or so)
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Discussion Starter · #21 · (Edited)
Ok, ok, bossy...;)


What is needed for this project:

Skull Mold, or skull to make a mold out of.
Mother mold for the mold.
A clear casting resin. (more on that later)
A well ventilated work area.

First, obviously, is making the mold.

Instead of rewriting a bunch of stuff I've already posted, I'll just direct you to my mold making tutorial here:

http://halloweenforum.com/tutorials-step-step/67547-glove-mold-making-101-a-2.html#post444665

And highlight what we're doing different for the Crystal Skull.

For the resin we'll be using, you want relatively shallow nose and eye cavities, and they should be filled in accordingly. I used Model Magic again, as in the tutorial above, but I have come to find the new Crayola Air Dry clay to be both better and cheaper. But, it needs to be allowed to dry, and sealed with a coat of a lacquer spray. Were I to start one today, that's what I would do.

If you are using the Lindberg Skull, you will need to add some clay to the nose bone as it's too thin, or remove it and sculpt your own.

We also need to fill in the gaps behind the teeth if you're keeping the lower jaw. I filled the entire jaw cavity with model magic.



Now that the model is prepared, make your mold as listed in the tutorial above, however, we want to encompass the model fully, only leaving a small area to pour into. And, reinforce the ENTIRE MOLD with the cheese cloth. Top, bottom, undercuts, whatever. The resin we're using is heavy, and we need the reinforcement to keep it's shape.

CUT a seem from the pour location as far back as you need to remove the mold.

The use of the seem also will make things MUCH less easier and less of a mess than attempting to rely on the latex stretching when it comes to removing the mold, and it's best to reinforce the seem with the cloth to prevent ripping. Thus, the decision to cover the whole with cheese cloth.




Now then, tape that seem back together. I crossed the seem with electrical tape, then ran the length of it with painters tape. But, were I doing this again, I'ld skip the painters tape and cover that seem with more of that air dry clay, let it dry, and duct tape it in place.



The Mother Mold:

A mother mold is just something to keep the mold itself in the proper shape.

Some of those plaster bandages you can buy at michaels would be great. Some plaster itself would work. Anything. I used Model Magic because it's what I had, and I didn't want to get to the store.

Just made a framework for the mold, broke it in 2 (so it could be removed later), and taped back together in ******* moldmaking glory.





The Casting...

I'm using Castin' Craft Polyester Clear Resin (AVOID the "easy cast"), which you can read more on here, because that is what Michaels had, and I had a bunch of 40% off coupons to use. Without the coupons, best price on it is available from Delvies Plastics. Delvie's Plastics Inc.: Casting Resin

They also sale a bunch of tints, if you want a colored one.

I'm tempted to suggest the 'surface curing agent', because this WILL come out sticky/slimy. But, I have no experience with it, and the now 2 dozen or so I've cast (most of them mini skulls my son sold, see mold making thread above) all the surfaces have hardened over time.

IF BUYING FROM MICHAELS you need to ALSO purchase the Catalyst seperately. Delvies sends enough catalyst with each package of resin.

THIS GIVES OFF A STRONG ODOR and poisonous fumes while curing. VENTILATE the area well.

THE CATALYST WILL BURN you if its in skin contact long. Gloves, people. And I hate gloves. And, FYI, I had one bottle, new, that had some residue of the catalyst on it's lid. My fingers paid for lack of gloves a few hours later.

CURING PRODUCES HEAT And lots of it. PLEASE allow the mold to COOL completely before attempting to remove. As mentioned above, the stuff will still be sticky, and sticky heat on your skin is not a good thing.

Now come the questions:

How much do you need? If using the Lindberg Skull as prepared above, just under 1 gallon. If not, fill your mold with water, and dump it into a measuring cup.

To fill the mold completely and without gaps will require 2 seperate pours. One for the brain cavity, and one for the face, so mix 2/3 up, and pour it in, then tip the mold upright and allow to cure. Then tip it back and do the face.

HOW MUCH CATALYST DO I NEED?!?!?!

THIS is THE question. And...I don't have a definitive answer...since the instructions only list thicknesses up to 1 1/4"...and we are WELL beyond that. Further, we are doing a 3 dimensional mold, which the directions simply tell you to consult the mold maker.

Too much catalyst, the polyester will crack under the heat. Too little and you get a gooey mess.

Fortunately, there's a wide middle area where a little too much just turns it a bit yellowish, and a bit too little just makes it take longer to cure. And, as mentioned, I did 2 dozen smaller ones to get a feel for how this reacts with 3 dimensional molds.

I'll edit up this spot with what I used when I get home and can be absolutely sure of the measurement, not post from memory. I do know I erred on the low side, as this particular skull took a few days to cure, and a week for the surface to fully cure after releasing from the mold.

EDIT: I used for Skull 1: 2 drops per ounce, 16 drops per cup. And, yes, I mixed a cup at a time as it was all I was comfrotable being sure it would accurately get measured and thuroughly mixed. This was on the lower side, and each pour took a good 24 hours or more to harden up, but a part of that was due to the fact I did it in less than ideal temperatures. Patience is a virtue here. You could likely pump it to 20 drops per cup just fine, likely even more if you are pouring at a consistant room temperature.

Skull 2 is a whole other ballgame as it's mold required 5 seperate pours of much smaller volume. I'll get it's picture up soon.

Skull
Hopefully Skull 2 is a bit closer to the proper #. (should finish it tonight)
 

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Just a word of caution - if you over catalyze polyester resin it can catch on fire. Also, polyester resin is very brittle and can shatter if dropped. If you are going to convert these into animated skulls, you might want to use a 2 part urethane resin. They make high strength resins (such as Task 2 by Smooth-On - I use this to make prop helmets) that would probably work well for this application.

Randy
 

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Discussion Starter · #23 ·
There are other products to make this, to be sure.

Clear Urethane resin is a fair bit more expensive (roughly double), would likely be best in a silicone mold, is touchy to moisture and humidity (discolors the clear), and requires the ability to accurately measure and mix the 2 parts at the proper temperatures. The cost alone turned me away from these.

Epoxy resin being the other I know of. Again, it was more expensive, but not much, and in my experience is VERY touchy to both temperature and accuracy of mixtures (often not simple 1:1). Ruined one of the smaller skull molds exploring this as the stuff never set up, another came out more a frosted glass look, a third was nice and clear. Which was aweful confusing to me as I measured and mixed all 3 at the same time.

(I'm not even counting any products requiring hot pours)
 

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Discussion Starter · #30 ·
I don't think these would do well for animation.

They weigh a fair amount, and you'ld burn up your servos pretty quick.

You'ld need a hollow casting to get it light enough, and to have space for all the items to animate it. (which would be seen) That would require some other equipment just to get the casting, I believe.
 

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I see what your talking about. But if you were to hole them out you could make it look like a brain... UUmmm Brains... Brains..... BRAINS!!!!! (LOL)
Very nice work on what you have here and thanks so much for sharing the info.
 

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**Question UnOrthodOx

what kind of spray(??) did you use to cover the clay filling in the holes in the skull you cast your mold from. **xcan you remove the clay after the casting?
I got a liquid latex mold from AC More with a 40% off yesterday and to it is 50% off the next one.
 

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Discussion Starter · #33 ·
Sealing the clay would not be completely neccesary. You'ld just have to be willing to clean off the clay from the mold prior to casting in it.

In fact, I did not seal the mold builder at all, and just manually cleaned it off. (peals off easy) The Air Dry claw I used for mold 2 is a finer grain, and would therefore be more difficult to clean off completely, so, I sealed with just a spray paint clear lacquer. In such a case, it would be 'removable' but you would need to sand/scrape/remove the lacquer, most likely.
 

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Cool thank you
I was also asking... could you clean the clay from the skull to use in another project?I have an older model skull I got for my Airbrush studies, that I can use. and I also got AMACO rubber latex, for casting the inner mold. and some magic mold.
I also got some **none drying clay**. I was thinking of applying it to the surface of the skull to form more interesting fetchers, and or expressions.
 

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Discussion Starter · #35 ·
It's probably an oil base clay, then. And, I have no experience with that in reguards to how it reacts to latex molds. Oil is typically not great for latex, but I don't think there's a whole heck of a lot of it in the oil clays.

What I would do is make a tiny model out of the clay and dunk it in the latex. Let that latex dry, if it peels off, you should be fine.

The only time I've used a 'wet' clay, we had a little trouble getting it cleaned off the latex mold. In fact, it made 2-3 plaster skulls with little bits of clay imbedded in them before it was all out. Not a problem for plaster, but would be for the 'crystal'.
 

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Ok, a pair of those would be absolutely perfect for my next prop... Unfortunately I definitely do not have the resources to build those for myself... Is there a way I could put an order in for a pair of those from the UnOrthodOx.com website? :D (Ill even pay for the over ngiht delivery since it would take me less then 10 minutes to pick them up!! :eek: OGDEN, UTAH?)

(It is great to see a fellow haunter on here from Utah!!! :) As you can see I have been away for a little while... :eek:)

That is simply amazing work... Thanks for posting!!!
 

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Discussion Starter · #37 ·
Ok, a pair of those would be absolutely perfect for my next prop... Unfortunately I definitely do not have the resources to build those for myself... Is there a way I could put an order in for a pair of those from the UnOrthodOx.com website? :D (Ill even pay for the over ngiht delivery since it would take me less then 10 minutes to pick them up!! :eek: OGDEN, UTAH?)

(It is great to see a fellow haunter on here from Utah!!! :) As you can see I have been away for a little while... :eek:)

That is simply amazing work... Thanks for posting!!!
I'm not entirely opposed to the idea of selling some stuff. But, really have no idea how to even get set up for that. But, were you to, say, swing by one day with a little cash, I have been known to let a few things go from the garage in the past...

But, for the moment, I'm about a month out before I can make some more. All the nearby Michaels are out of the resin for some reason...:rolleyes: and are not getting more in soon, so I'm waiting on an order to come in from Delvies, and then we're painting and reflooring the entire upstairs in the house, so propwork will be put on hold for that for a few weeks too.
 

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Sounds like you are very busy!!! Thanks for replying... Ill bother you later. If you need an extra hand with flooring let me know. Always willing to throw my back out. :D
 

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Discussion Starter · #39 ·
The power was out most the day Sunday, so not much to do but cast another crystal skull.

This would be design #2.

Among the features being that it requires about 1/2 the resin, and the carved design, IMO, looks great in 'crystal'. Where a more 'realistic' skull has that supernatural "how do they do that" feel, I think this stylized version makes it feel more tribal. Perhaps made in reverence to the truly mystical 'real' one. I don't know, still playing with the idea of these.



Love all the little facets and how they all catch the light different.



Next to skull 1, for comparison.



I would note that I bought some of that surface curing agent for this one. And I'm most unimpressed. I'm thinking the best way to get rid of that tacky feel is to spray them with some lacquer after they're fully cured and cooled.

Next up, I'm dying some to make an amber one and a ruby one.
 
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