Thursday, September 29, 2011

BJD Head Mold

There is a great Flicker gallery about Molding and Casting a Doll Head.  Keep in mind this isn't the only way to mold/cast a head.  I don't plan to get into details about all the ways you can mold a bjd head since the above gallery is how I plan to do Arisu's head.

The above diagram that I made in Inkscape will help illustrate what I am planning to do.

1.  The beige color is for the non-sulfur clay buildup.  I plan to give my bjd's head a removable faceplate so that means her neck joint must be joined with the back of her head.  If I made a removable head plate, her neck joint would be joined with the front of the head.  At this point I would pour the silicone rubber for the first part of her head mold.  What you can't see in the diagram is the need for mold keys in the clay buildup.

2.  With the clay buildup removed her head is now ready for the second pouring of silicone rubber.  If you haven't noticed yet, there are no pour holes in either of these parts.  The pour hole was not accidentally forgotten but is part of the plan.  After pouring the second silicone mold for the head, it is time to make the head hollow.

3. & 4. This next part will be the third pouring of the silicone mold and requires a lot of care.  A clay buildup is made inside the head and face molds at the same thickness as I want the resin copy to be.  I would also be adding the pour hole and air vents.  The air vents will help bubbles from getting trapped by creating areas where they can escape.  My diagram does not indicate where I plan to add the vents, but if you look at the gallery I posted at the beginning you can see how it can be done.

A.  This is where the neck joint is.  I did not include a diagram of how I plan to make this slot yet, but be aware that some clay sculpting is needed in this area to ensure a proper neck joint socket is made.

B.  Her head will have magnets to help make it easier to remove her faceplate and to hold it in place.  I will have to make a buildup in clay for this.  Additional means to help keep her head aligned will be needed as well.  The hard part is to have both halves of the head match up.

C.  If I were to put clay over her eyes, I would have to cut them out after every casting to make the eye hole.  Instead of adding extra work, her eyes will be devoid of clay so that the silicone will pour into it leaving an empty spot when the resin is cast.  Extra care is needed to ensure the clay buildup around the eye is not too thin and has clean lines.

Her head has a total of 4 parts to make the head and face plates separately.

Part 1 & 2 REDO
Part 3 & 4 


I am just about set to start making my first silicone rubber mold.  I have my molding kit, safety equipment, mixing items, mold box, and my BJD's head is ready.  Most importantly I have read and watched all the instructional information that came with my molding & casting kit.  All I would have to do now is make the clay build up for the first pouring of silicone rubber.

The BJD's head is going to be a 4 part mold to make her head hollow and to make her face plate separate.  This will require 3 separate silicone mold pourings.  Each pouring takes 6 hours to cure.  Between pourings I will have to either remove or add clay for the buildup.  So I figured I would need at least 2 days to dedicate to this.  Although I could do one pouring today I won't be able to do the other pourings until sometime next week.  (I will be gone for most of Friday to Sunday, which also means no updates during that time either.)  As eager as I am to try one pouring today, I think I will wait until next week.

I will also be pouring the silicone mold for the eye I made last week.  I haven't quite decided whether I will do a simple one piece mold, a single block mold with cuts, or if it will be a 2 part mold.  The first option will have a smooth back and the last two options will allow me to have a stick attached to the back of the eyes.

So check back next week to see how things went making a silicone rubber mold without the use of a pressure pot.

Sunday, September 25, 2011

2.2m Sculpting (Arisu)

Here is an update on Arisu's head.

She finally has her ears.  It was difficult to add the details to it so I made her ears rather simply.  I may try to detail it a little more, but overall I am rather pleased with how it looks.  The only thing left to do is to smooth her head out, but I only have up to a 400 grit sandpaper.  I was thinking of using panty hose to do that.  I did notice that wax became smoother when I made moulage mold out of the piece, so I may try dunking her head in warm water.  Of course she is going to float though since her head is hollow

This week I should have a test run with making a silicone rubber mold and casting in urethane resin.  The question is, what will I use for the first test?  Am I daring enough to try her head right away or stick to something that might be easier?  hm...

Friday, September 23, 2011

10mm Eyes Project: Part 1

Since I have been spending a lot of time working on Arisu's head, her eyes have been a topic on my mind.  Right now her head has a 10mm bead (which is actually a little less than 10mm according to my digital caliper).  But when her head is finally cast in resin I will want something better than beads.

BJD eyes are made of various materials such as glass, urethane, acrylic, polymer, etc  The glass eyes are less likely to scratch but does not have much detail.  The urethane eyes can have better details then glass eyes, but can scratch more easily and may yellow with age.  Both glass and urethane eyes are costly with a pair costing easily near $40-50 for a pair.  Then you have your acrylic eyes which can cost under $10 a pair.  Since acrylic eyes don't interest me, I didn't research much into it.  And if you wanted to make your own eyes, you have the option of making polymer eyes.

I am not ready to pay over $10 a pair of eyes, but I don't want to buy acrylic either.  And having polymer eyes wasn't too appealing.  So what am I to do?  Attempt to make my own urethane eyes.

So I first made a mold of the same type of beads that are her eyes right now.  I tried to make a moulage mold first but since these beads are so small it wasn't working out.  I ended up making a one piece plaster mold of half the bead to create a  half sphere.  When the mold was dry enough it was soaked in water to water log it before casting carving wax into it.

Above you can see the plaster mold on the left that I made.  Then next to it on the right is a carving wax casting.  I removed the extra wax from one of the half spheres and added a 2.5mm rod down the middle.

To get a round eye, I placed the rod into the shaft of a cordless dremel.  I used the dremel on low and placed sandpaper against the wax to slowly smooth and round it out.

I used a 4mm rod to make a dip in the top middle of the eye for painting the pupil and iris.

The question is, now what?  Do I make a rubber mold and cast in resin?  Or should I make a putty mold?  Make it in polymer clay to refine and test it before wasting expensive materials?

Ideally the eye would be cast in urethane resin and then the pupil/iris is painted.  A clear coat of urethane resin would then be added on top.  If needed the eye will be sanded down to a smooth and shiny surface.  The urethane resin eye would need to be bubble free.  Can I make a bubble free eye without a pressure pot?  I don't know.

More thinking needs to be done.

Thursday, September 22, 2011

Mold Making & Casting Starter Kit

My Mold Making & Casting Pourable Starter Kit has arrived.

This kit includes:
2.9 lbs. OOMOO 30 - Silicone Rubber
1.9 lbs. Smooth Cast 300 - Casting Resin
2 fl. oz. Ease Release 205 - Release Agent (with spray top)
2 fl. oz. SuperSeal - Sealing Agent (with spray top)
and instructional information including a DVD.

From the Smooth-On the trial kits for the rubber and resin  (bought separately) is a little over $50 (not including shipping).  The above kit cost $46.33 (not including shipping) from, plus you get extras.  Not a bad deal.

Monday, September 19, 2011

More Thoughts on Silicone and Resin

When it comes to silicone and resin there are 3 companies I noticed have been mentioned a few times by BJD makers. (There are more companies out there so if you are looking for silicone rubber and urathane resin, look around.) They are Smooth-On, Alumilite, and Polytek. Since I prefer to buy the silicone and resin from the same company, if possible, I decided to go with the company Smooth-On since their resin Smooth-Cast 305 is recommended.

Of the Smooth-On Silicone Rubbers offered, a few have caught my interest. Mainly Mold Max 30, OOMOO 25/30, Mold Star 30, Dragon Skin 30, and Sorta Clear 40. There are two categories of silicone rubbers: tin-cured and platinum-cured. The shelf life of tin-cured is not as long as platinum-cured. So if I was making a mold that doesn't need to last years, tin-cured should be fine. But if I want to make a mold of a more valuable sculpt, I would go with a platinum-cured silicone rubber. Of the rubbers I listed above, Mold Max and OOMOO are tin-cured. Mold Star, Dragon Skin, and Sorta Clear are platinum-cured.

So which one to use? Without a pressure pot, I need to use a silicone rubber that has a very low viscosity, which is the OOMOO line. The difference between the OOMOO 25 and 30 is the pot life, demold time, and shore hardness.

If I had a pressure pot and wanted a platinum-cured rubber, I would want to try the Dragon Skin 30 or the Sorta Clear 40. I am very interested in using a transparent type silicone rubber since this would allow me to see through the mold for cutting.  But for now I have to settle with what I can use without a pressure pot.

Since I have no silicone rubber molding making or urethane resin casting experience I decided to purchase the Smooth-On Pourable Starter Kit from DickBlick to give it a try. This kit comes with a trial size of OOMOO 25, Smooth-Cast 300, Ease Release 205, plus extra. At $50 it is a good start to have all you need to try molding and casting. I will be posting more about it when I get a chance to try it out.

I failed to get Arisu's head done this weekend but it should be done by the time the kit arrives... I hope.

Saturday, September 17, 2011

2.2l Sculpting (Arisu)

Almost done with the details of Arisu's head.  It has been a rather difficult journey, but my next doll's head should be easier to do.

Below is her head as of tonight.  It seems I need to do a little more work on her nose and get her ears set.  Then I need to sand the surface smooth.

Notice her nose is a bit crooked?

Nose is a bit thicker than I like.

Notice right nostril is not looking good.

Otherwise her head is coming along really well.  It can be hard at times to see the different between the last head I posted and this one since I sand here and there in little amounts.  I am looking for uneven surface and coverage.  Her lips were finalized.  I won't be posting another head shot until I can get her ears done.  And then I get to test run making a silicone rubber mold and casting in urethane resin.

Friday, September 16, 2011

Thoughts on Silicone and Resin

My ultimate goal for my bjd Arisu is to cast her in resin.  Of course I am not anywhere near done and am still working with her in carving wax.  Only her head is nearly finished.  Even so, I want to try making a resin copy of her head to get a feel for how the final product will look.  So how do I get my resin prototype?

The urethane plastic resin I decided to try for my prototype bjd head is Smooth-Cast 305, which seems to get good feedback from other bjd doll makers.  It is white, has a 7 minute pot life, and has an ultra low viscosity.

I plan to use a silicone rubber for the mold, but I am still not 100% certain about which one I will use.  I need to research this more, but one that has caught my interest is the Smooth-On Sorta Clear 40.

To make the silicone rubber mold and urethane plastic resin prototype bubble free, I am going to need a pressure pot and air compressor.  This is where it gets expensive or not depending on whether you buy it or make it on your own.  If you made one,  you would make some modifications to a pressure paint pot.  Either way, what I want is a 2.5-5 gallon pressure pot.  I am leaning more towards the 2.5 gallon unless I can't find the one I want and the 5 gallon is the best value.  So far I am considering the Jet 5 Gallon Resin/Mold Casting Pressure Pot.  That would cost me about $350 with shipping.  Still higher than I want to pay, so I am still looking around.  If I can only find a good priced 2.5 gallon resin pressure pot...

Interesting Links:
Easy Resin Casting - pdf
Pressure and Vacumm - pdf
Using a Pressure Chamber to Create Bubble Free Casting - by Smooth-On
Molding and Casting a Doll Head -  on Flickr

Wednesday, September 14, 2011

2.2k Sculpting (Arisu)

I found her head to be lacking in the forehead department, so I added wax to her head.

Here is how she looked before...

And here is how she looked like after the makeover...

After adding wax and sanding it down with 100 grit sandpaper, her head is looking much better.  But notice her nose is flat.  Let's just say she keeps falling on it.  Well, more like I accidentally drop her head and she lands on her nose almost every time.  I need to be more careful with that.

I am hoping to have her head done by this weekend.  Then I can start working on her body.

Carving Wax Sheets

One way you can add carving wax to your sculpt is by make a sheet of wax.  This is similar to what you might do if you were making a wax sheet candle.

First you need a source of hot wax to pour.  I use my wax cup which sits on my candle warmer.  This warms the wax to about 145-150F.  The more wax that is in the cup the more likely the top layer of wax will solidify.  So I normally have enough wax in the cup so it is 1/2"-1" deep.

To make a sheet of wax, pour hot wax onto wax paper.  Keep in mind the hot wax will spread outward so either have enough wax paper to handle that or don't pour too much.

You can help make the wax sheet thinner by laying another sheet of wax paper on top and pressing down evenly with a flat object.

The above picture has the wax sandwiched between two sheets of wax paper so I can flatten it.  This will prevent the hot wax from sticking to the object you are using to press it down.  You can also make textures by pressing an object with a textured surface.

While the wax is still warm, you can cut and shape the wax.  What I did with the above sheet of wax was cut a long ear shape out of it.

While it is still warm you can shape the wax sheets.  I welded it onto another piece of wax using my wax pen.

Above you can see a few more angles of what I did.  Once it cooled, the wax became stiff.  I am not sure how useful this technique will be, but I will be doing this same thing to make human ears for my doll Arisu.  This should help ensure the ears are even in size.

You can also make larger wax sheets by lining a pan with wax paper.  Make sure you fold the wax paper so the sides are also covered.  You can also use this method for making thicker sheets of wax.

Monday, September 12, 2011

2.2j Sculpting (Arisu)

I took a few days break from working on Arisu, but I am back to working on her.

Yesterday and today I spent a considerable amount of time working on her head.  Since I made sandpaper pieces I was able to give her a good sanding to help finish her head.  I went down to a 220 grit on her head and was able to get rid of drips and bumps.  I also finished off a lot of her face's details.  She is still lacking ears though.

She has a separate face plate which will allow me to make new faces for her and change them out easily.  I still need to work on how her head comes together and is taken apart.  It will involve the use of magnets.

Most of her eyes were done with the 10mm beads in place.  When I was happy with how she looked, I removed them and cleaned up the lines.  I think she is looking really nice now.  You can also see how I did her nose and cleaned up her mouth area.

I even cut her body into 2 parts in preparation of attempting to make her body joint.

So far I am very pleased with how her head looks.  I still need to add her ears to finish her head.

Sunday, September 11, 2011

Sanding Carving Wax

I bought a packages of sandpaper that are 9"x11" with grits 100, 150, 220, 320, and 400. Not sure if I need all those sizes but since I got the variety package, I have lots of choices.

Below you can see that I placed the grit side down to make cuts. I made both horizontal and vertical cuts prior to separating the pieces. This made things go a lot quicker.

Each 9"x11" sheet made 36 - 1"x2" and 9 - 1"x3" pieces.

Now I can start sanding my carving wax doll parts.

Monday, September 5, 2011

Carving Wax Shrinkage: Plaster Mold

In another post I talked about Carving Wax Shrinkage.  Today I had some time to do the plaster mold parts of the test.

Overview:  Test plaster mold in room temperature (80F) and warmed (100F).  Test carving wax at 145F and 160F.  Make 5 casts per test combination.  Casting will be done of a plaster tile made with a 5cm line.  Plaster mold was created 2 parts water to 3 parts plaster of paris.  After pouring wax on the mold wait a few seconds then place in water to help cool.  This will help decrease the wait time for tiles to be cool enough to remove from plaster mold so it can be cast again.  Temperature is measured using a Radio Shack infrared thermometer.  Accuracy of temperature measured by the device is unknown and not of great importance.  An electronic caliper is used to measure length round to the closest tenth of a mm.  The caliper is zeroed out prior to use each batch of 5 tiles.

Plaster mold room temperature (80F).
Carving Wax Temp 160F 145F
1. 48.7 49.0
2. 48.6 48.7
3. 48.8 48.9
4. 48.8 48.7
5. 48.9 49.1*
Total:  243.8 244.4
Average:  48.76 48.88
Shrinkage:  2.48% 2.24%

* The plaster mold line was stuck in the carving wax cast, but enough reminded on the plaster mold to continue using for tests.

Plaster mold warmed (100F).
This part of the test that I planned to do was stopped due to issues.  Since the water used to warm the plaster mold as well as cool down the wax on the plaster mold were the same, this created problems in this scenario.  Out of 5 attempts to create tiles, only 2 were removed properly.  It is unlikely I will be repeating this situation when I do cast carving wax in plaster molds so there was no point to continue this part of the test.

Conclusion: If you take into account the 10 tiles I measured, the shrinkage range is 1.8-2.8%.  The average shrinkage is 2.36%.  The mode shrinkage is 2.6%.  The median shrinkage is 2.4%.

(1 - (measured line length from cast wax / actual line length from plaster mold))*100 = shrinkage %

I noticed when I had my carving wax at 145F the shrinkage percentage was smaller than when I had the carving wax at 160F. Coincidence or is there something more to it? The difference is 0.24%. Not much.

Although my carving wax recipe did not have the same shrinkage as kwm's observations, it is not far off.  While working with carving wax you tend to remove wax here and there also adding to the shrinkage.  But at least take into account 2.5-3% shrinkage should help ensure your wax carving size is closer to the final size.

Now the question is how shrinkage works when recasting and using moulage molds.  That is for another day.

Friday, September 2, 2011

Carving Wax Shrinkage?

Q: How much does Carving Wax Shrink?

The only source of information I could find on this is from kwm at Atelier de Poupee. The post states ".02777%. Almost 3% shrinkage."

Why is there such limited information? Different combinations of ingredients are going to have different results.

The recipe I followed for my Carving Wax:

4.5 parts microcrystalline wax
4.5 parts paraffin wax
9 parts talc
1 part beeswax
1 part carnauba wax

The recipe for kwm's Carving Wax:

1 part paraffin
1 part microcrystalline wax
2 parts talc

Notice that we also have a slight different in the recipe for the carving wax. Basically, kwm omitted the use of beeswax and carnauba wax. How will that affect the difference in shrinkage?

So how do I test carving wax shrinkage? I am going to make a plaster mold of a tile that has a 5cm line that can be measured.

How reliable will that information be?  Just measuring one carving wax cast isn't going to be enough.  Although I could probably get more accurate numbers casting and measuring 100 times, I am not about to do that.  So I will just settle for casting 5 times and getting an average number.  Things like the heat of the mold, the heat of the wax, etc may all factor in to the calculation of shrinkage.  I will try to take in as many factors as possible, but there is a limit to how much I will test.  I am just trying to get a general number for shrinkage and not one for scientific application.

Why is knowing shrinkage important?  Lets suppose you first make a plaster mold of your original sculpture.  Then you cast with carving wax.  Then maybe after some work on that carving wax copy you make a junk moulage mold.  You cast another carving wax copy from that mold and work on it some more.  Maybe even after all that you want to make another junk moulage mold and cast in carving wax again.  Maybe you repeat that a few times.  Depending on carving wax's shrinkage, your original sculpt is getting smaller every time you make a new mold and cast it in carving wax.  This may not be a big deal if the size of the final copy does not matter.

Something else that needs to be factored is the mold's shrinkage.  Plaster mold has no shrinkage, but what about junk moulage molds?  It is recommended to use a moulage mold as soon as it is set and not to just store it for later use, but why?  Because of shrinkage.  So what kind of shrinkage are we talking about?  If I stored a moulage mold in an air tight container for a day, how much shrinkage are we talking about?  What if I stored it for a week?

So many questions that I want to find some basic answers for.

So what am I going to test for?

Plaster Mold
Test room temperature and warmed up plaster mold.  Test pouring 145 and 160 degree carving wax.  Cast 5 times per scenario.

Moulage Mold
Test room temperature mold.  Test pouring 145 and 160 degree carving wax.  Test using moulage mold immediately, 24 hours later, and x days later.  Cast 5 times per scenario.

Sounds like a lot of fun.

Thursday, September 1, 2011

2.2i Sculpting (Arisu)

I have been spend a lot of time on Arisu's head since I have started on a new one.

I bought some 10mm beads for her eyes.  The face is still rough so there is a lot to do.  I have decided she will have interchangeable face cap.  In the second picture you can see the line where the face cap is.  The line near the ears to the bottom of the face is not a definite yet though.

I do wish I had some rasps though.  I have been adding wax to certain areas that dip and using my small metal file to smooth it out.  Unfortunately the wax clogs the file, so I have to burn it out with the alcohol lamp.  Best to do that outside.  Better to get the uneven surface dealt with now.