Making huge TPE breasts

Thebonerbrigade · Post by **Thebonerbrigade** » Tue May 14, 2024 4:21 pm

I've been experimenting with melting and reshaping TPE the past months. I've made several promising mixtures; some soft but durable, others almost exactly as soft and jiggly as fat (but very weak). My long term goal is to create a pair of TPE breasts with each boob being around 2 feet in diameter, use the more durable mixture for the outside, and fill them with the softest mixture. Given the size it doesn't matter much if they are connected like traditional breast toys or if they are individual boobs. I believe this project is possible due to TiddyShop's 106lb breast toy and a Twitter user that made a 128lb pair of individual breasts.

The 2 things I am trying to figure out are how to make the mold, and how soft I can make this before it just falls apart. I've made 4 inch sphere tests that are super soft and hold up well to a lot of squishing/manhandling. I will be making a 8-12 inch scale model sometime soon. I don't have good enough math skills to figure out how soft it can be outside of making larger scale models.

For mold making, my ideas are ordered from most expensive to least expensive. All involve building a large box/flask to surround the object, then covering the object in a liquid silicone casting kit to make a mold that I can then pour TPE into:

Buy a Z cup breast form. Cover in silicone kit.

Make individual sphere out of ~50lbs clay. Cover in silicone kit.

Buy a large exercise ball and cast in concrete. This might not work because the surface would be porous.

Buy a large exercise ball and cover in silicone kit.

This was inspired by someone on Twitter making a similar product apparently at home, maybe using plaster. They only speak Japanese and refuse to reply to any messages asking how this was made. I'm essentially trying to reverse engineer their work and improve upon it if possible. The attached pictures are their work, not mine. The exercise ball method seems like the best place to start but I'm certain it will be tough to make a mold of. Clay would be useful for sculpting the nipple instead of attaching it after, but would be quite hard to make a smooth sphere with. The breast form method is easiest but requires a molding box twice the size and costs minimum $600 or so. Thoughts?

Thebonerbrigade · Post by **Thebonerbrigade** » Tue May 14, 2024 4:28 pm

The softest TPE mixture I've made replicates fat very well. It deforms in your fingers from only gravity much like a real breast does and is extremely soft. It even spreads apart (doesn't hold its spherical shape) when lying on a surface but doesn't fall apart. This is what I am planning to fill the breasts with. It holds up well to handling when I filled the 4in scale model with it.

carbohvdrates · Post by **carbohvdrates** » Tue May 14, 2024 4:49 pm

Why not get one of those super large birthday balloons, fill it with air, THEN coat it in clay? If it's not firm enough to cast like that then maybe you could fill the balloon with a can of expanding foam and let it harden first. That's gotta be more convenient in cost and weight than a 50 lb orb of clay.

Technician · Post by **Technician** » Tue May 14, 2024 6:15 pm

This is a really cool project but aren't you going to make like a 150 LB pair of juggs in the end? They seem like, as awesome as they are, REALLY heavy. The fat filling might just flatten out under it's own weight.

Thebonerbrigade · Post by **Thebonerbrigade** » Tue May 14, 2024 7:11 pm

carbohvdrates wrote: ↑Tue May 14, 2024 4:49 pm Why not get one of those super large birthday balloons, fill it with air, THEN coat it in clay? If it's not firm enough to cast like that then maybe you could fill the balloon with a can of expanding foam and let it harden first. That's gotta be more convenient in cost and weight than a 50 lb orb of clay.

Expanding foam in a balloon sounds like a great idea. I'll have to give that a shot. One of my worries with an air filled balloon was that it would deform under the weight of liquid silicone, but the foam would help with that.

Technician wrote: ↑Tue May 14, 2024 6:15 pm This is a really cool project but aren't you going to make like a 150 LB pair of juggs in the end? They seem like, as awesome as they are, REALLY heavy. The fat filling might just flatten out under it's own weight.

Yes they will be very heavy but that's kind of the point, I want a pair of giant heavy tits haha. Most commercial breast toys are firmer in both shell and filling to survive being thrown around in shipping. The only reason I'm not too concerned with the high weight is because the one I'm modeling this off of is about the same size/weight and it holds together fine. They might be using a firmer filler but I can't tell. I'm okay with the boobs flattening out under their own weight (after all that is what real breasts do). My main concern will be making sure the outer TPE layer doesn't rip apart from the weight. I'm guessing I will have to make a couple versions before I figure out how thick it needs to be. And clean up some messes lol.

RevJack · Post by **RevJack** » Tue May 14, 2024 9:28 pm

I would go exercise ball covered in HYDROCAL. Hydrocal is a super hard super smooth cross between plaster and cement. Super smooth. One quick spray of thinned petroleum jelly and I cast TPE directly into it. It will hold skin texture so it works for nipples. Nipples is mostly what I use it for.
Inflating a balloon with expanding foam will not work. The foam doesn't expand evenly or equally.
I'd do a big boobie mold, and a couple of nipple molds of different size/types of nipples. Sculpt the nipples in your clay, make a negative in Hydrocal and then spray it with release and cast right into it.
That way you can try out multiple nipple types and sizes.
To re-enforce your mold, lay strips of burlap soaked in Hydrocal criss cross. A couple layers of that is insanely strong. I've done full body casts using that method.

Reverend Jack

Technician · Post by **Technician** » Wed May 15, 2024 2:16 am

What are you guys using to melt the TPE? Did you make extruders?

RevJack · Post by **RevJack** » Wed May 15, 2024 8:11 am

Technician wrote: ↑Wed May 15, 2024 2:16 am What are you guys using to melt the TPE? Did you make extruders?

Doll TPE is not extruded, it is just hot poured. It must be heated slowly and evenly since it sucks in heat transferable. I use a small oven and a cast iron pot out in the workshop. A fellow tinkerer put a (used) full sized oven on his back porch for TPE, uses really thick steel pots.

Heat slowly, and stir stir stir. It will scortch and burn on the outside and be cold as a corpse inside. I shred mine before I melt it.

Reverend Jack

Thebonerbrigade · Post by **Thebonerbrigade** » Wed May 15, 2024 11:04 am

Technician wrote: ↑Wed May 15, 2024 2:16 am What are you guys using to melt the TPE? Did you make extruders?

I'd love to have an extruder but I do not have the setup for one. I take the TPE I have, chop it up into small chunks or slices, put in a large pot, melt and mix on ~3/10 heat, and mix in mineral oil as needed. If this loses any TPE in the heating process it hasn't been a noticeable amount. I then pour the TPE directly into the silicone mold I have to cool for at least 12 hours. It produces quite a bad smell so I wear a mask and keep the area ventilated.

Apec23 · Post by **Apec23** » Sat Jul 13, 2024 10:15 pm

I’m late the party but I believe the z cup idea would work well,

Thebonerbrigade · Post by **Thebonerbrigade** » Fri Sep 13, 2024 6:34 pm

I haven't had a chance to make a full scale mold yet (space limitations) but I have done some more experiments with TPE I think are worth sharing.

My previous pours into silicone molds had some issues with bubbles present on the surface after cooling, so this time I used a metal mixing bowl that I preheated via steam. This left the surface smooth due to the hot poured TPE undergoing a smaller temperature change. TPE companies do the same thing just in a much more effective way, not a hot bowl haha. The trick is to evenly heat the entire mold which is much easier for something smaller/silicone.

Secondly I proved that a larger-scale TPE product can hold its shape even with significant mineral oil amounts. Both the 4.5in diameter sphere and the 11.5in diameter bowl shape do not deform under their own weight or when shaken roughly. Obviously the bowl does not simulate the same affects of gravity as a sphere does, but I am confident it can hold up well. This is important because a large scale could lead to more tearing; every TPE breast toy on the market is quite a bit firmer than what I just made. If tearing is a concern for a full-scale model, I can adjust the thickness of the outer shell to compensate.

Next step is to make a similarly sized model that is more of a sphere. A deep, rounder mixing bowl used in bakeries could be used, or I may try making a scale model mold. TPE stickiness is an issue I have yet to solve outside of powdering with cornstarch.