Friday, 27 June 2014

Wrist surgery


I took some extra time to prepare this post because I wanted to turn it into a more global tutorial. I was just about ready when Blogger had this annoying glitch for a couple of days. What was up with that? It drove me crazy! I half prepared another post while saving this one for a time when people could actually see it, but now it's fixed, and I know I kept the suspense long enough. I'm happy to say I got to the bottom of the blackening issue, then made a new wrist replacement, and another one for a different (not broken) doll. I now present you a full tutorial for fixing broken wrists/elbows/knees on any doll that uses the kind of joint seen in the first picture. The beauty of it is that it uses common materials and can be adapted for any size and colour!


Short summary if you didn't see the first post: my J-doll had a bad wrist that broke when I tried to move it. I made a replacement part and put it back, but it turned dark when I was putting the finishing touches. I decided to take it apart and see what could be done.
Now we'll look at what happened next. I'll try to arrange my findings in a logical succession.

What was all that black

I opened the wrist first thing the next morning. To my surprise, there was no sign of rust on the pin, no dirt or discoloration inside the joint, nothing that would suggest anything went wrong.


I shrugged and went on to make a new joint, one that didn't include exposed metal, just in case. It hit me much, much later. I had used acrylic primer to fill in some gaps in the hand. The doll material is slightly translucent, while the primer, even in a thin layer, is very much opaque. When I held the paper where I mixed the primer against a light, it was the blackest black. I understood this when I peeled the "bandage" from the forearm. Some primer had stuck inside.

Hello, nightmare!
  
Sure enough, all the mystery blackness went away as soon as I cleaned it with a toothpick. I can't believe I was fooled by elementary optics! By the way, I decided not to mess the crack with glue; it doesn't open anyway unless there's a drill drilling inside the forearm.

The hand translucency is still a bit of a problem. When you repair something, you have no choice but to use materials and substances with different light-reflecting properties. As you can see in the finished hand with peg, from some angles the match is flawless:


...but tilt it a little and it's suddenly zombie hand. Mind you, that is not a shadow from a bump that we're seeing - that part is perfectly smooth:


I'm not bothered now that I know the explanation for this phenomenon. I'm just happy my doll can play the violin again. Let's see how to make that possible.

Preparation

I'll start by listing the materials and tools I used for all steps, explanations later:
Materials:
- pliable aluminium wire. Avoid steel, silver and other metals that change appearance over time. I used both floral (stripped of coating) and thinner beading wire, both are fine. About 0,35-0,5mm diameter, small piece
- wire cutters or scissors
- flat-nose pliers
- non-patterned part of a paper towel, separated into plies
- gel super glue, NOT the drippy kind
- nail polish or some other waterproof varnish
- toothpick
- nail files, buffers, or fine sandpaper
- pin or tiny drill
- drill with small drill bits (I used 2mm for the J-doll) - not pictured
- X-acto or craft knife - not pictured
- sticky tape - not pictured
- optional: watercolours, gouache, acrylics

The type of joint that I set to repair has a connector with two moving parts. There's a peg inside the forearm that gives rotational movement and a hinge for flexing the hand. I'm talking about the wrist here, but a Monster High leg, for example, has the same anatomy. The knee is the hinge and the peg is inside the thigh. When stressed, the joint will break between the peg and the hinge ring, rendering both elements useless. Any attempt to glue them will reduce mobility. Thus it is necessary to make a whole new connector to replace the broken one, but first we need to clear some room for it.

Removing the connector pieces

To cut the hinge out of the hand, slide a thin, sharp blade along the sides of the central ring. Try to just cut through the shaft that holds it, don't make a hot mess like I did.

I had to add an extra step because of this ugly cut

The peg is pretty much impossible to get out, so the easiest way to get rid of it is to drill through it. Wrap some scotch tape tightly around the limb containing the peg to prevent cracks (I wrapped it after a tiny crack formed - learn from my mistake). 


Drill slowly. You may start with a thinner drill if you find it hard to control. A 2mm drill proved just right for the J-doll wrist. The hole isn't very centered, but it looks fine when assembled. 


The doll is now ready to receive a new connector!

The connector

1. Cut a small piece of wire, just big enough to be handled comfortably. Tear one ply of the paper towel into a strip the size of a ...finger? It's not important, we'll adjust it later. Have a small dowel handy for forming a circle. I used the tip of a toothpick.


2. Fold the paper lengthwise, put the wire inside and roll. It's easier than it sounds. I guess you can use glue, but I didn't find it necessary. The thin paper towel clings well to the wire.

3. Hold the middle of the wire against the toothpick while twisting the ends together. Don't pull too much or the paper will break.

4. After twisting a sufficient length, use pliers to flatten the base of the ring.

My photos didn't turn out great so here are some from the first attempt

5. Squeeze some gel superglue over the whole thing. Use a toothpick to spread it evenly across the whole surface, including inside the ring. It will be crazy sticky, so don't let it touch any surface for about a minute.


That's it, that's the connector you need. If you wait for it to dry thoroughly, cut the ends and put it in, it will work. But we should make it pretty, too!

6. Sand all bumps. Note the places where it needs filling in. Mine needs an even girth of the peg and a bigger ring.

First version of the connector on the bottom, for size reference

7. Use more paper towel strips and superglue to "grow" the connector. Fold a strip in half, apply superglue, fold in half again; apply glue on the connector and wrap the prepared strip around. The edges should be wider than necessary, we can always file down. Hold the ends down with toothpicks or you'll glue your fingers together :)


You can smooth small imperfections with nail polish. I used one very similar to the doll's colour. Wait for everything to dry completely before moving further.

8. Repeat sanding, building with paper and nail polish until you've achieved the right size and texture. The peg should fit inside the hole (you may cut the extra length whenever) and rotate freely. The ring should be a perfect circle, level with the hand surface.

If that is the case, you are ready to assemble the joint. If you destroyed the "skin" while removing the old hinge, see the bonus chapter.


Colour version

"But Arina", you say, "we don't all have nail polish that matches the doll's skintone! What to do?" The answer is simple - tint the towel beforehand!

In this example, I used mum's watercolours to create a Frankie green. I made patches of different concentration. Mixing, diluting and painting the towel took me less than a minute.


The colour really builds when you start rolling.


It darkens further after soaking in superglue. Here is a comparison of the darkest and the lightest sample. The lightest was barely visible when dry and in a single layer. Bear this in mind when mixing your shade. The finished item will have the colour of the wet towel folded in several layers.


This is a very rough outline of the Frankie connector. I built the ring to the right size and sanded. I didn't even apply (clear) nail polish, although I recommend it for waterproofing. I used beading wire so I'd add extra padding to the peg if I were to use it, but thankfully, none of my dolls have broken joints.


The tinting test went well, don't you think?


Assembling the joint

The hinge needs a new shaft instead of the plastic one we cut in the beginning. It doesn't have to be as thick as the original. I used a piece of wire with two coats of nail polish. I found that the J-doll hand pierces easily with a pin, but depending on the doll, you may need a thin drill.


Put the connector in and check all the different angles. You can still remove it and adjust it at this stage.

Because my wire was thickened with nail polish, I used a thumbtack to enlarge the pin holes.


I cut the wire to have a clean end which I used to insert into the holes with the connector in place. I pulled until I had a painted segment inside the joint. It's probably not necessary to paint the wire if it doesn't contain steel; I did it as an extra precaution.


Snip one end of the wire. To avoid wire stumps sticking out of the hand, pull the other end back by a little bit, veeery carefully.


Snip the other end and push the stump in. You can cover the little holes if they bother you. I just put some of that nail polish which I later sanded.


If you used a drill to create a new shaft, you may want to draw some "skin care" advice from the next chapter. Otherwise, you're done! Insert the peg where it belongs and marvel at your amazingness.

Bonus: Skin repair

I screwed up big time when slicing the hand to free the hinge. As a result, my first attempt of fixing the wrist, while functional, looks like a computer mouse with a wheel. Compare it to the healthy hand. Yikes.


To fix the skin, I used - you guessed it - paper towels and superglue! I squeezed some dots on the edge of the gap, placed a towel ply on top, spread more glue over the part that didn't touch the hand, and let dry. Two layers of this seemed enough to me.


The two layers, dry and sanded. Already looking much better!


You could tint the towel before using it to restore skin. I just used my magic nail polish again.

Meant. To. Be.

Nail polish also gives the "skin" more flexibility. The shine can be sanded or muted with matte varnish.

Wait for it to dry completely before cutting the excess with tiny sharp scissors. Have the connector ready and test that you are only cutting away parts that impede movement. I snipped by very small bits. You can see one on my middle finger and some on the table in the background.


There is always room for improvement, but I drew a line at this point. The important thing is that my doll's poseability is fully restored and, considering the initial state, the fixed wrist blends in pretty well. What do you think?


Not that I wish broken doll joints upon anyone, but if they do happen, I hope you find help in my tutorial. Share any results, questions or opinions in the comments below!

The Black Kitty
(^^)~~~

6 comments:

  1. I still think that is an impressive feat of dolly engineering. I'd never think of half of this stuff on my own, so thank you for sharing, although I hope that I never need it. When I first saw the title of your post, I was afraid that *you* needed wrist surgery. Then I remembered your ongoing J-Doll saga! She looks much better now.

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    1. Oops! Sorry I scared you :) I do actually have a bad wrist, but as long as it's in one piece... I wish people were as easy to fix as dolls.
      Although it took some efforts to write, this is the one tutorial I hope nobody ever needs. You can take it as a reminder that most things can be fixed if we put our mind to it. You know what they say, "necessity is the mother of invention". Or was it laziness? I have plenty of that too :) Glad you enjoyed this post!

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  2. Glad you found out where the mystery black came from! And different materials really can look incredibly different (or similar) just depending on the light.
    Personally I'm a bit wary of using nail polish on dolls, since I tried it once and it had a weird reaction with the plastic. I've heard other people use it, though.

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    Replies
    1. What did you try to do with nail polish and what happened to the plastic? I think most of the accidents are caused by solvents on hard plastic, while rubbery hands other soft parts seem to do just fine. It's also possible for nail polish to shrink or crack faster than artist-grade varnishes, but this worries me little, since it was applied directly on the doll only on the shaft holes. I think it will last for a good while before I have to refresh or replace it.

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  3. Oh wow, never would've thought of this in a million years! It really does blend in well.

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    Replies
    1. Thank you! I wouldn't have thought of it either if the wrist weren't broken.

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