Does anyone know how to mold a hollow head?

[MeltedCaramel]

Sorry for such a strange question guys! To give a little backstory, I've been dissatisfied with the Obitsu bodies for a little while now. Not their functionality (they're incredible that way) but their aesthetics. I often find myself desperately trying to find a body that looks okay shirtless or showing off their arms, some skin, something, while still keeping in with that anime aesthetic. The Volks Neo Goh bodies are by far the best option, but they're unicorn-rare (seriously, anyone feel like selling I'm right here! *raises hand* ). I also want a little bit more option in the male side of things in the 1/6 community, There seems to be "young boy" Obitsu and then the male Obitus go from "slim with no definition whatsoever" straight over to steroid-bulked. I've been seriously looking into creating a small line of my own 1/6 bodies, something along the lines of the Volks aesthetic (muscle definition, etc) with the ease-of-worksmanship that an Obitsu body has. I want to create mid-teen boy bodies, a sort of hybrid (aesthetic wise) between the Neo Goh and the Obitsu. I want different skin types. I've already found a pourable resin (haven't been able to find liquid ABS plastic yet) that would probably be pretty ideal.

But. The hands and the heads. Both are made of PVC (I believe? Can anyone tell me exactly what these guys are made of, Barbies and Obitsus/etc?)? And, here comes the big question: How in the heck do I create a mold that is hollow and able to be rerooted!? I'm looking to both cast a few of the Volks heads (and I desperately want to resculpt one because I feel it would work much better for both males and females with a little touch up!) plus my own designs.

Can anyone help? Tips? Tutorials? Tricks? Anything?

[zirconmermaid]

First off - if you are recasting for your own use, that is one thing, but remember that Volks holds the copyright on their products. That includes using one of their heads as a base for one of your own if you intend to market a head.

I will now remove my moderator hat.

Now, as to what you wanted to know: Obitsu and Volks are a combination of Vinyl and ABS plastic. The heads are Vinyl, the harder parts are ABS Plastic. Making hollow vinyl requires very expensive and specialized molds that are made of metal. ABS plastic also uses very hot metal molds. If you would like to see how this is done I recommend this site: http://www.dannychoo.com/en/post/27195/Smart+Doll.html Danny Choo goes into great detail with pictures about the process. The time I did doll prototyping I believe that the creator paid over $10,000 per doll to get them made. So, bad new - expensive. Good news, it can actually be done.

What I suggest you do: Have you considered learning to do 3-D modeling on a computer? There are many 3-D printers available now that are more and more affordable. And they print in ABS plastic! It is safer than resin also.

If the head will be a "one off" you could use the paper clay method.

If you make a resin head, you can manually drill the holes before rooting, or you can just wig the head.

To make a hollow mold you basically make a mold of both the outside and the inside of the head. There are lots of tutorials online that show how to do this. There have even been some here on DS.

You could petition Kiki-chan78 to print her Allison bjd as a 1/6 doll. She did do that with the Alice, and it's available as a 3-D print. It's not cheap but the doll is lovely. She makes a fairy line. [url]sweetdolls-bjd.com[/url]

There are other makers that also do 3-D printed dolls. Again, not necessarily cheaply.

Volks and Obitsu are not the only 1/6th scale vinyl jointed doll. Look for anime boy dolls. Also look for Taeyang bodies. He's the boy version of Pullip and is equivalent to Obitsu - frequently the body is replaced by Obitsu.

[MeltedCaramel]

First off - if you are recasting for your own use, that is one thing, but remember that Volks holds the copyright on their products. That includes using one of their heads as a base for one of your own if you intend to market a head.

I will now remove my moderator hat.

Now, as to what you wanted to know: Obitsu and Volks are a combination of Vinyl and ABS plastic. The heads are Vinyl, the harder parts are ABS Plastic. Making hollow vinyl requires very expensive and specialized molds that are made of metal. ABS plastic also uses very hot metal molds. If you would like to see how this is done I recommend this site: http://www.dannychoo.com/en/post/27195/Smart+Doll.html Danny Choo goes into great detail with pictures about the process. The time I did doll prototyping I believe that the creator paid over $10,000 per doll to get them made. So, bad new - expensive. Good news, it can actually be done.

What I suggest you do: Have you considered learning to do 3-D modeling on a computer? There are many 3-D printers available now that are more and more affordable. And they print in ABS plastic! It is safer than resin also.

If the head will be a "one off" you could use the paper clay method.

If you make a resin head, you can manually drill the holes before rooting, or you can just wig the head.

To make a hollow mold you basically make a mold of both the outside and the inside of the head. There are lots of tutorials online that show how to do this. There have even been some here on DS.

You could petition Kiki-chan78 to print her Allison bjd as a 1/6 doll. She did do that with the Alice, and it's available as a 3-D print. It's not cheap but the doll is lovely. She makes a fairy line. [url]sweetdolls-bjd.com[/url]

There are other makers that also do 3-D printed dolls. Again, not necessarily cheaply.

Volks and Obitsu are not the only 1/6th scale vinyl jointed doll. Look for anime boy dolls. Also look for Taeyang bodies. He's the boy version of Pullip and is equivalent to Obitsu - frequently the body is replaced by Obitsu.

I never meant recasting the Volks guy heads for selling! I need them for myself! I was expressing my displeasure at the lack of variety on the market for 1/6 guys. I'm quite well aware of the Taeyang (the bodies don't really appeal to me, not to mention the head options get kind of limited). And anime boy dolls are far and few in between, most of the ones I can think of come from the Tsukuda hobby line and are of...90's quality, I'll leave it at that. There really isn't any equivalent to the lean anime guy of the Volks Neo Goh out right now available for customizing without costing an arm and a leg for either a full character doll to break apart for parts, and again, 90's quality. A Taeyang also costs around $60 (conservatively) and that's not including shipping to the US, so even if they were an alternative from my perspective, they are way too expensive. I would be perfectly fine doing this entire sculpting/casting thing for myself, just to have more variety to work with. And when I say "hybridizing" something I meant molding it myself but using the same type of simple joining system if I were to actually SELL something (though that's not really my end game here, anyway I don't think there's a huge market for what I want to do! )

For the "ABS" parts of the bodies I would actually be working with a two-part resin compound that can be tinted and used in silicone molds. It's marketed as mimicking ABS plastic quite well.

If it's just for the heads, I'd be willing to pay to (or learn how to) make my own metal casts for them. Having soft vinyl is really a sticking point for me. Wigging dolls just isn't feasible for a lot of the characters I end up making, sometimes I just need to be in control of rooting the exact hairstyle. I haven't been able to find ANY tutorials on how to make hollow head molds though, and I've trawled the DS archives as well thinking maybe someone had already posted one. If anyone can link to these tutorials I'd be much obliged.

As for 3D printing...again, there's the same sticking point of the head. I would love to learn how to 3D print, but as a project separate from this. I really want to flex my own artistic and customizing skills here. Kiki-chan's dolls are incredible, but again, not what I'm looking for.

[MeltedCaramel]

Here's a bit more of what is stumping me. I get the whole idea of making a core mold, as shown say, on this blog: http://atelierpoupee.blogspot.com/2010/ ... orial.html

But nowhere does it show how they manage to make these giant hollow heads with tiny neckholes. By reasoning, wouldn't the core mold end up stuck in there because the neck hole is so small?

[DollyKim]

I'm sensing it's a similar principal to wax casting. Pour in the stuff, swish it around to coat the edges of the mold, pour out the excess and let it cool, remove the mold. Or stick a balloon inside the mold, inflate, fill mold, deflate balloon when cool. The heads could be made in two separate pieces, the seam line is along the hair line or there's a head cap plug, then heat bonded together.

I'm more familiar with using air dry clays and the idea of press molds and polymer clay. Haven't made it to plastics yet.

The book Pop Sculpture covers a lot of modern mold making and casting for action figures in plastics.

[Faydreams]

Actually, take a closer look at the heads when they have no hair. You will notice that they have a small circle at the top of the head where the crown of the hair would be. The mold for the barbie heads is actually two parts. One for the main part of it and the hole at the top for the inner mold removal. Since it stretches a little when warm the inner mold would just pop out of that crown opening. Then they cast the crown plug and basically melt the two pieces together. That's what causes that slight ridge of thin vinyl around the crown plug. The inside of the neck hold (depending on the company) might also be another mold that is later attached.

A good head to look at for seeing what I mean is the Monster High CAM heads. That hard plastic plug where the wig attaches would be what I mean by the Crown of the Hair.

[MeltedCaramel]

Dollykim- I thought about that balloon method for a really long time actually! My only issue with that was the issue of it just creating a "bubble" of sorts and not leaving a lot of room around the forehead area for rerooting. I do own "Pop Sculpture", I think I'll take another look at it!

Faydreams- I noticed that too, and in fact I chopped a spare Obitsu head I had in half to look at that area. There seems to be a particular method to doing this though because it's always bonded completely and thoroughly and if often has a "shiny" look to it. If I could figure out how to bond these two pieces completely I could successfully make molds this way. I'm just stuck on the method they use to fuse the two together! But thank you for pointing this out, it's quite helpful to demystify this entire process.

[DollyKim]

I'm thinking it's a het set adhesive, polymer clay "glue" goes on as a liquid but cures in to a solid.

I can see filling the head mold part way then sticking in the male part to make it hollow. The male part squishes the skin around the mold and it fills up. Some of the principals of candy and Jell-o molding could come in to play.

[MeltedCaramel]

I'm thinking it's a het set adhesive, polymer clay "glue" goes on as a liquid but cures in to a solid.

I can see filling the head mold part way then sticking in the male part to make it hollow. The male part squishes the skin around the mold and it fills up. Some of the principals of candy and Jell-o molding could come in to play.

I can see what you're saying in theory, however cutting into the head shows there's not any kind of adhesive or bond, it just looks like both have been set together completely. There's also a hole in the round crown part of every single head that I'm positive plays a part in this whole moulding process. I really wish someone knew in detail how the heck they moulded Barbie/Obitsu/etc heads! Arrrghhhh!

[DollyKim]

Any extra holes would be to allow expansion gasses to escape. It could just be heat bonded together, melt just enough and they'll bond as they cool.