I probably could have made a lot of money from this method but I have no interest in manufacturing dolls so here it is for the benefit of all!
This method (that I came up with through experimentation with silicone and different types of fabrics) creates a high quality, strong, super soft silicone/fabric/silicone sandwich (composite) skin with no seams. A full skin can be stuffed with anything you like but for realism I suggest a second water tight skin that acts as a bladder, filled with fairly cheap and non-toxic Sodium Polyacrylate because it mimics breast, butt and thigh tissue/fat/muscle perfectly when encapsulated in a stretchable bladder (wouldn’t it be great if doll manufacturers incorporated this to save cost and add realism!?) Plus if you want you can incorporate resealable tubes that lead to bladders in the butt, breasts and thighs which would allow you to independently adjust them as big or small as you want at any time… just add or remove Sodium Polyacrylate!.
Between $70 – $300 Largely dependent on if you keep the mannequin or sell it afterwards.
The main things you will need and approximate cost of each…
[$25 – $30] A Full Lycra/Spandex Zentai bodysuit without head (fingers/toes optional depending on if your mold/mannequin has them)
[$100 – $135] Platinum silicone, flocking/pigment of your choice, mold release and 3 or 4 small roll on applicators. (Using thinned and silicone oil softened hardware store tube 100% silicone may work if you don’t use too much oil. A better option may be to soften with Smooth-On Slacker® additive ($20) which should prevent the hardware silicone from losing a lot of strength (though I have never tried it). QUICK TIP: Smooth-On will send you samples of their various silicones, just email or call them!
The trick here is getting the right size bodysuit with the right fabric. You want it to stretch enough so that the fabric opens up and lets the silicone through in order to create a mechanical bond that will reinforce the weaker chemical bond to the fabric. For this reason you may want to order a bodysuit one size smaller than what the sizing chart recommends. Also, although there are fixes for it the thinner the better because convex areas can become more concave the thicker you make the skin. This means primarily nipples may not look exactly right if you make the skin too thick around them. The best way to fix this is either make the skin thinner in that area or make separate nipples and attach them later. This is also where using Sodium Polyacrylate as filling comes in handy because it can provide pressure from inside to push out the parts that should be convex.
PREP THE MANNEQUIN
Put the Zentai suit on the mannequin and make sure you can see through it at least a little bit. This means that the suit is probably stretched enough to allow enough silicone through for a mechanical bond. Because there are variations in fabrics and silicones, I suggest you get some scrap pieces of the same exact fabric your suit is made of and stretch 3 or 4 pieces of your fabric to different degrees on top of some plastic with clamps to hold them at the ends then apply silicone like in the instructions below, let it cure and see which worked best by stretching them. The ideal bond will allow you to stretch it as far as it will go without the silicone forming cracks or peeling.
Remove the Zentai suit and turn it inside out for later.
Most mannequins come in pieces so they are easy to ship. After putting your mannequin together you will need to fill the seams where the parts join with sulfur free modeling clay (if you are using platinum silicone). To get it smooth, use a spray bottle filled with rubbing alcohol and a sponge. Spray the seams and wipe with the sponge, this will partially and very temporarily dissolve the oils in the clay. Repeat until clay is smooth with the edges of the mannequin parts.
OPTIONAL STEP: To create a vagina or fully encapsulated place to put a vagina insert you can attach a rod sticking out of the mannequin from where the entrance of the vagina opening would be that is long and wide enough for you. Since the skin will be turned inside out after it is done this will leave a hollow area for an insert. Or you can use some extremely softened silicone to make a gel and fill it with that! You can even use some of your modeling clay to make the labia majora.
Next you need to apply a mold release that is suitable for the type of silicone you are using, all over the mannequin. Follow the instructions recommended by the manufacturer, this isn’t rocket science.
SILICONE SKIN COAT
QUICK TIP 1: Having a more liquid/flowable (lower cps aka centipoise) silicone for the first few coats makes this process much easier. Look at a CPS chart like this onehttp://www.cstsales.com/viscosity.html to get an idea of what cps numbers correlate to common liquids. For the first 2 coats you are probably going to want a 1,000 to 1,500 cps. Use silicone thinner or thickener as required. Remember that colored Flocking (if you use it) will slightly affect your silicone making it slightly thicker (higher) on the cps chart. It adds more realism to the skin but is not required.
QUICK TIP 2: It is a good idea to take notice of your silicone’s advertised cure time, as you will want a little longer to work on the first few coats. You may need to use some cure retarder depending on the silicone you are using.
Start by mixing enough of your silicone and skin shade pigment to cover your entire mannequin from neck to toes all in one go. Using cure retarder here helps you not be rushed so use it if you need. Apply a thin coat with a small to medium size paint/foam brush and let cure fully. I have come to like the foam brushes for thin coats because they are less expensive and seem to do a better job. You can use the paint brushes for the 3rd coat.
After first coat has cured, apply a second coat exactly as the first and let cure.
The 3rd coat doesn’t need flocking and should be a little thicker and this time you probably want to use cure retarder because you are going to need enough time to apply a coat, then put the Zentai suit on your mannequin while it is still un-cured, mix another batch of silicone and apply that coat over the Zentai suit, all before the coat underneath cures!
The 3rd and 4th coat is the most critical step because you want to get a mechanical bond, and the best way to do that is sandwich the fabric with a bit of pressure between 2 coats of uncured silicone and then letting it fully cure. If you wanted to get really crazy with it you could even vacuum bag the whole thing but I don’t think it is required if you follow all the directions here.
You must apply a hefty amount of release agent (petroleum jelly/Vaseline is even better) carefully to JUST the length of the zipper from top to bottom because you want the silicone to stick strongly to the fabric all the way up to the edge of the sides of the zipper but not the zipper itself. This will prevent silicone getting inside the zipper which would prevent you from being able to unzip later and remove the skin from your mannequin!
Once you have applied a release agent to the suit zipper turn the suit inside out (so the fabric’s seams end up on the inside of the finished skin) and then put the suit on the mannequin. With the 3rd coat of silicone still curing underneath, mix up a batch of silicone for the 4th coat (this time it doesn’t need pigment) and apply it with a paintbrush on top of the body suit. Once you have that coat evenly spread over the mannequin use the rollers to press the silicone deeper into the fabric all over, focusing around the sides of the zipper as well as the spots where there will likely be a lot of stress and chance of tearing, such as groin, elbows, knees etc…
I recommend letting your skin cure for a good 3-5 days or more past the demold time indicated for your type of silicone to maximize bonding through the fabric. Most silicones continue to cure for up to 7 to 10 days past their demold time.
Once you are sure the silicone is fully cured, use an exacto knife to cut a slit all the way down along where the zipper is underneath. Once you have that open you can unzip the zipper and then use your exacto knife to cut through the second skin layer that was created during the 1st and 2nd coats.
At this point you should be able to fairly easily remove the skin from the mannequin and turn it inside out, provided you used enough of the right release agent!
I have to run, but I plan to update this with pictures soon in new posts below. I have yet to do this on a full mannequin but the process is the same regardless.
Also looking forward to see if anyone has ideas to improve this method.