More Durable Foot Project (Experimental)

[Dutch_Husband]

I have been tinkering with an idea to make the TPE foot more durable than they are when they come from the factory. I don't have a lot of time to devote to this experiment, so it may be a long process. I am posting it here as a record of my progress as I go. Maybe some of you will find it useful.

First, let me say that this idea is NOT about converting a non-standing foot to a standing foot, although my idea could extend to that.

Second, for those following along at home, I accept no responsibility for anything you do to your doll. If you try any of this, you do so at your own risk. These are just IDEAS.
Lastly, I welcome comments and other ideas, but I would prefer tested solutions. Suggesting this "might" work, or "maybe try" something isn't really helpful unless you have actually done it. Then if it worked, great! If not, why not? What went wrong? etc.

THE PROBLEM:
Like most noobs, I thought the best way to do the initial cleaning of my doll was in the shower. In the process of carrying her, her feet hit the door frame causing very small cuts.
TPE is quite resilient, but it has a low Tear Strength. So while it will stretch considerably, it will tear easily anywhere it is cut if put under tension. Thus, small cuts become bigger if not repaired right away.

The non-standing foot is decorative only. It is not functional for what feet are designed for... supporting weight and for balancing. If you stand a doll with non-standing feet, all of the body weight is placed on the skeleton and compresses the TPE material at the sole of the foot directly under the foot plate. With that much pressure, any sideways movement (if she slides or bumps something), can easily damage the sole.

Standing feet attempt to solve this by extending the skeleton through the sole with support bolts. This removes most of the weight from the sole of the foot, BUT only if the doll is standing on a hard, flat surface. If she is standing on carpet, the bolts push down into the carpet and the sole of the foot comes in contact with the carpet potentially causing damage.

So far, the best solutions have been:

Never stand a doll on non-standing feet, (but they can still be damaged during movement).
Always keep the feet covered with socks, (socks don't always provide enough protection).
Make your doll wear shoes, (I don't like her wearing shoes in bed).

It seems that what needs to happen is to make the sole of the foot out of a more durable material.

I did a bit of online research to understand how a human foot actually functions. It's primary purpose is for weight support and balance. Any idea what purpose the big toe has? It is primarily used for balance. Yet even the standing foot has a flexible toe.

When it comes to weight distribution, the majority of the weight is carried on the heel and ball of the foot. I found this chart from a podiatry study online:

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So it is no coincidence that these are where we find a lot of foot damage.

Another consideration is that I don't want to alter the appearance of the foot too much. Face it, the sculptors do a great job at creating beautiful feet! But I don't like the looks of the standing bolts on the sole. But truthfully, most of the time, the part of the foot we see is the top and sides, not the bottom.

My thought is, what if we could replace the sole of the foot with a more durable material? Something that will stand up to pressure, remain a bit flexible, mold-able and neutral in color.

The stuff I have been testing is called Shoe Goo. http://eclecticproducts.com/products/sh ... e-goo.html
It is designed to repair shoes (leather, vinyl, rubber, and canvas). It costs $5 a tube and you can get it in most shoe departments where they sell shoe polish and water-proofing. It is very durable, flexible, clear in color and is like very thick silicone sealant... so mold-able. Uncured spills can be cleaned up with acetone. When fully cured, it is hard, but flexible, like the sole of a shoe.

I have personally used it on a variety of things from shoes (canvas, leather, and plastic) to fishing waders (vinyl) and even rubber inner tubes. It works very well!

I tried testing it on TPE and it does not stick unless the TPE is cleaned very well with acetone. Note that it STICKS, but does not actually bond. So it can be peeled off with enough force, but mostly stays put.

The non-standing foot provides no support at the heel or base of the toes, so we will want to "stiffen up" those areas.

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The non-standing foot plate is quite small compared to the rest of the foot. This forces any weight on the sole into a small area, resulting in a higher psi (pounds per square inch).

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So while we are beefing up the sole, why not give the sole more support by increasing the surface area? While we are at it, why not make the bottom of the foot flat like the sole of a shoe?

The plan is to cut away the sole and refill the area with the Shoe Goo.

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Since the Goo may not stay put over time, we don't want to "anchor" it to TPE. I think we might want to cut all the way down and around the foot plate. Regardless if the plate is metal or fiberglass, the Goo can be wrapped around the plate like sandal straps to help keep the new sole in place. Then just fill the void with more Goo to the surface of the existing sole so we have a wide, flat standing surface.

I am still waiting on my repair tools (hot iron, heat gun, etc.) to arrive from Amazon before I actually start cutting. I will update as things progress.

[kklouzal]

Good luck Dutch_Husband and I look forward to seeing your progress! I agree that the feet are a definite area for improvement in regards to a dolls functionality.

I was torn between standing/non-standing feet when ordering my doll. Yes I wanted the ability to stand her up but every image of a standing foot I saw screamed danger Will Robinson. Ultimately I went with the non-standing option because I was too afraid that the TPE was going to rip around those holes where the bolts stuck out. The aesthetics of the bolts is no issue however any rips on the body is inexcusable. Needless to say I wont be standing my doll, she'll have to make due with laying in bed for the majority of time. She can sit in a chair or the edge of the bed but probably only for short durations as not to put creases in the TPE near bent joints.

Any improvements to help distribute the weight over a larger surface will reduce the PSI by spreading it out over that larger area. No matter how large you make the foot plate though you'll still have 60+ pounds (30+ kg) crushing down on whatever material is in contact with the floor. I like your idea of replacing the material under the foot plate with something stronger. I'm not sure how well your Shoe Goo is going to hold up though, it may have the strength however you're going to want something that bonds to the TPE very well.

[Dutch_Husband]

Thanks, kk.

The key is that we don't want to bond with the TPE, it is too "fragile". If you glue a piece of metal to a piece of paper, you won't have the strength of the metal. The stress will be on the weakest link, so to speak. I want to leave the TPE to be the cosmetic part, but strengthen the structural part to resist damage.

The goal is not to make her standing, but to make the sole less likely to be damaged. If the Shoe Goo does hold up well, then standing becomes an option.

To that end is why I am considering wrapping the Goo around the foot plate so it bonds to that part of the skeleton, thus supporting the weight over a wider surface area. I haven't opened the foot yet, but there is a cut all the way to the plate, and it looks like the plate is fiberglass. If the Goo binds well to the plate, that will be a bonus. I am planning that it will not, so will need to wrap the Goo around the plate to support the sole.

Anyway, fingers crossed.

[Dutch_Husband]

Well, the heat gun arrived today, however the hot iron did not. Even though it arrived in town this morning, apparently UPS decided to keep it until Monday. That seems to happen a lot whenever I am waiting on something important. <sigh>

Another thought that occurred to me concerning the foot plate wrap. Shoe Goo may not adhere to the fiberglass (or metal) foot plate. But manufacturers have a similar problem keeping the TPE stuck to the skeleton. So they wrap the skeleton with gauze or canvas, and (I assume) use an epoxy to bond the gauze to the metal frame.

I can do the same thing by wrapping the foot plate with gauze. Shoe Goo is designed to bond with canvas, and I know from experience that it will.

So I'll apply some epoxy to the foot plate, wrap with several layers of gauze and let it cure. Then as I build up the Goo around the plate, I can work it into the gauze to give it plenty of grip.

Well, that's the plan anyway.

[matt gloss]

[Dutch_Husband]

Surgery has begun.

I spent a few days, when we had warm weather, with windows open to practice with my new repair tools. Now that I am confident in using them, it was time to start cutting.

Evie's left foot has the most damage, so I'll start with that one. Even if this project doesn't work out the way I imagine it, at least I will have removed the damage.

She originally had a few small cuts in her heel. Since I didn't know how to fix it at the time, I left it. Through various movements, poses, etc. the small cuts became larger and more numerous. Her poor heel looks like hamburger.

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During my inspection and cleaning of the foot, I found more cuts on the side of her heel as well.

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The first step is to repair the cuts on the side. I don't want them getting worse while I am working on her sole.

That done, I removed the sole of her foot all the way to the foot plate.

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The plate is not fiberglass, like I thought. It is a curved metal plate wrapped in gauze.

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What I found interesting (ironic?) is that as easy as it was to damage the foot, the TPE does not want to pull away from the gauze. Neither a box-cutter knife, nor an Exacto razor blade would cut it! I had to use a sharp pair of scissors, then it cut nicely.

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Now the the next step is to remove the TPE from the gauze. The Shoo Goo will stick well to canvas, but not to TPE. So I'll need to clean off the gauze so the Goo has something to stick to. I may end up just gluing some strips of burlap around the plate if I can't get the TPE off. We will see how it goes.

[MikeOxbigg]

That's cool!!

[Dutch_Husband]

For the next step, I put a plastic tube on the end of a plastic syringe and used the syringe to suck some Shoe Goo into the tube. (That way I don't ruin the syringe with the Goo.) Oiled the tube with baby oil and slid it into the hole in the big toe, where the toe wire used to be. Then injected the toe with Shoe Goo. The Goo is very thick and the TPE stretched, making her toe look swollen. But after removing the tube and syringe, the normal elasticity of the TPE caused the toe to constrict and squeezed out the excess. When it cures, she will have a stiff but flexible toe "bone".

Next, I peeled the foot back to the ankle and coated the entire foot plate (top and sides) with Shoe Goo. I applied a layer of about 1/8-inch thick, then moved the foot back into place. Massaging the foot helped squeeze out excess and remove air pockets. It takes about 3 - 4 hours for the Goo to set up, then another 24 hours to fully cure. The fumes (like model glue) can be pretty strong so open a window.

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Now that this step has cured, I found that the TPE is staying stuck to the Goo very well... much more so than my initial tests indicated. The next step is to start filling the void on the bottom of the foot. The fresh Goo will bond with the cured Goo, so it is best to build it up in layers. I found that making a layer too thick takes longer to cure. This step took a full 48 hours+ to cure.

I also found that, although the Goo is thicker than toothpaste, it will try to run. So I had to keep her foot as level as possible, and check it often for the first few hours of cure time. But this also means that it will try to run down into any voids or pockets and fill those.

Here the void is mostly filled. So the next step will be to build up layers to level off the sole of the foot for a flat surface. Now that I see how well the Goo sticks to the TPE, I will extend the coverage to slightly overlap the edges of TPE for a bit more durability.

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[matt gloss]

best wishes

[secretagentman]

Hopefully you tested the shoe goo on a tpe sample.

I was glossing over the datasheet and shoe goo contains toluene and other hydrocarbons.

I didn't delve into the exact concentrations but as a general rule they aren't very compatible with tpe.

You might not ever have any issues or you may encounter them in varying degrees after longer-term exposure but either way I just thought you might want to know.

[Dutch_Husband]

Hopefully you tested the shoe goo on a tpe sample.

I was glossing over the datasheet and shoe goo contains toluene and other hydrocarbons.

I didn't delve into the exact concentrations but as a general rule they aren't very compatible with tpe.

You might not ever have any issues or you may encounter them in varying degrees after longer-term exposure but either way I just thought you might want to know.

Thank you, yes.
I tested on a sample first because:
1) I didn't know if the toluene would be too "aggressive" as a solvent, and
2) I didn't know if it would bond with TPE at all. It is designed to bond with vinyl, rubber, and canvas.

I found that, if the TPE is cleaned with acetone, the Shoe Goo will stick to it, but does not actually bond with it. It did not appear to degrade the TPE in any way.

As of now, the Goo has been in contact with the TPE for over a week, and so far, no adverse affects.

Once the Goo has totally cured, I will do a stress test and post photos. I plan to have her stand on that one foot on a variety of surfaces... shower, tile floor, hardwood floor, and carpet. Then examine the foot. I expect that the Shoe Goo will hold up well. What I don't know is, how that much pressure will affect the areas where the TPE and Goo meet under stress... the heel and edges of the foot.

I'll keep you posted.

[Olivia F1]

Super Amazing Mod! I was thinking of something similar using epoxy putty to bond to the foot plate and build up and finally paint. Good luck, can't wait to see the final reveal!

[Dutch_Husband]

Everything is finally cured and ran some tests. Due to computer issues, I wasn't able to post.
So here it is now...

The Shoe Goo has fully cured. Beneath the foot plate it is rather hard, but at the edges it is still a bit flexible.

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The plan was to have her stand on that one foot for about five minutes or so, then inspect the foot for any damage. I know the Goo is very durable, so I am mostly watching for separation between the Goo and the TPE since they do not bond.

In getting her dressed for the tests, I rolled her over without paying attention to her foot position. Normally, I point her toes so she can roll easily. I forgot so her foot was at 90 degrees to her leg, and when she rolled her big toe got twisted and crushed.

The stress caused the TPE to separate from the Shoe Goo at the ball of her foot (base of the big toe), but there was no damage. Further inspection showed that the "toe-bone" did not detach from the foot plate. It is hard to see in the photos.

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The test surfaces I planned to use were: Bathroom tile floor, shower/tub, kitchen hardwood floor, and carpet.

First, the bathroom scale... she checks in at about 87 pounds.

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I learned very quickly that standing her on one foot is nearly impossible. Her joints are too loose to maintain position, so I had to hold her with both arms around her waist. That prevented me from taking pictures while she was "standing". I also found that, no matter how I tried, her foot would not stay flat on the floor. All of her weight kept going to her heel, since that is where her leg/ankle connection is. I could push her foot down, but it would come back up a little. It might stay put if her ankle joint was really tight, but as is she can't balance on her foot, so the sole of her foot isn't bearing much weight at all.

I had her stand on the tile floor with all of her weight on just the one foot for about five minutes. Then did the same thing in the bath tub.

I checked her foot for damage, and there is none.

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Next I took her to the kitchen for five minutes on the hardwood floor, then on the carpet. By this time, I am getting tired so I had her lean over a chair. This freed up my hands to take some pics of her foot.
Notice that the Shoe Goo is not visible, so her foot maintains a natural look.

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So, it appears that the experiment is a success. When time permits, I'll restock my supply of Shoe Goo and work on the other foot. It takes about 1 1/2 tubes of Goo per foot.

When both feet are done, I will try again with her standing tests.

Oh my, that ass though...

[HonkyDonky]

I didn't manage to spend the time and read the whole post. But I did notice how amazing your dolls facial expression is. Well done. She looks so real

[Olivia F1]

Congratulations on you're successful experiment, that must be satisfying. Your mod is an advancement in standing and I may follow your instruction in the future.