About first personal casting

[Daniele]

Hello guys,

i'm starting to try my first self-casting of my selfmade sculpted miniatures.
I've sculpted it in SUPER SCULPEY FIRM + FIMO.

But i've an important question:

Because my sculpture is very detailed, i'd want split it in more parts, like most kit normally has.

But how to do it??

The sculpture has a metal armature inside it!
How does a master sculptors with their creation? Did they baking Sculpey and after that cut in small pieces a sculpture before casting?? Or they split sculpture before baking? And how they do it with the armature?

Do you now any tutorial or description about it online?

Thank you for your help.

 

[tomifune]

Every sculptor has different habits but you have to split it up before casting depending how difficult you want to cut it out of the mold. Sculpey is also very brittle after hardening so anticipate some breakage when you are pulling it out of the mold. No matter what tutorials you watch, you are still going to have to go through some trial and error.
Some sculptors still don't like sculpting for casting production and would rather just sell one offs.

Bob

 

[Mark S]

When considering personal casting one firstly needs to look for a good couch.............sorry I'm sure there's something I can find to do....cheers.

 

[1969]

Bob is correct you may experience some breakage with the polymer master when removing from the mould depending on what rubber you use, the harder the rubber the more risk of breakage, you could opt for a soft rubber with about shore 20 hardness which may help.
If the sculpt is already complete then your only option now for engineering for casting is to cut it, I would suggest use a junior hacksaw, that way you can cut right through the metal armature as well as the sculpey. Once cut you may have to make good the contact points as you will have lost a couple of millimetres from the saw cut.
Cheers
Steve

 

[Gaudin]

It may help you to arrange to see how someone does molding - you will soon understand how you need to simplify shapes and avoid awkward angles.
Mind you, some casting wizards manage some really complicated shapes. On the other hand, Sergei Zlobov once has been asked to cut a figure into many parts, most unnecesary, but client felt that hobbyist seem to favour kits with a lot of parts to assemble.

Best thing to do is to learn to sculpt with casting in mind and plan in advance.

You can opt to sculpt parts as you go (for example do legs and torso and then add separate arms) or choose a stage at which you separate the figure - usually before fine detail is sculpted.

Here is an interesting example by one of the finest:
http://www.planetfigure.com/threads/continental-infantryman-1st-maryland-1781.71468/

If you use copper wire- it will be easier to cut later. Like Steve said, junior hacksaw works, fretsaw may do less damage and be more precise , I have seen someone use serrated scalpel blade, so choose what works for you.


You may get more specific advice if you post pictures of your figure.

 

[theBaron]

I learned a tip from Alan Ball, to use putty to make your armature, and then, if you have to cut up your master to arrange it in a mold, you're not cutting through a wire.

Prost!
Brad

 

[Tony Barton]

With Polymer clay , I avoid the need for an armature by working in full relief on a tile.
Fire the first half, then add the second to the now solid front half. You can continue adding and firing as many time as you want, so long as you don't overcook it at any stage.
Metal armatures tend to cause cracking eventually because of differential expansion .
Granted, I am mostly making small scale figures, but I find it also works with larger ones, though they do go a bit soft when hot , and you should be careful they don't flop over by supporting them in the oven and as they cool.
As someone has already said, you have to consider the casting from the outset , and design accordingly, and unfortunately, as with most things, experience matters most.

 

[Scotty]

Could you use a tinfoil/aluminum foil core to give it a bit of extra strength while baking?
Scotty.

 

[jasmils]

Daniele, Post a photo of the sculpt. Depending on the sculpt, you might be able to cast it in one piece.

 

[Daniele]

Thank you to all for your advices. I'll put some picture soon. Meanwhile, i understand what i must do. Thanks!

 

[garyhiggins]

Daniele, the engineering of sculpted figures for casting means going through a period of hard learning that may need some reappraisal of how you are working, what materials you are using and how you use those materials.
If you intend to cast the first thing you need to do is plan out your engineering before you start sculpting and to know how much of a breakdown you need to do, you need to know what medium you are going to cast in (resin or metal).
If resin, you can get away with fewer breakdowns because the rubber for resin casting is much more flexible and has better tear strength whereas the rubber for metal casting needs more breakdowns because the rubber is stiffer and less flexible and will not take undercuts.
Personally, for sculpting I find polymer clays a bit too fragile for multiple part sculpts and I prefer to use a two part putty (for choice MagicSculpt), but everyone has their own favourite.
Everybody has their own working methods, but I prefer to do the engineering at the armature stage and get the joints done first, that way I don't have to cut the figure up afterwards.
The best thing to do if you can is to get someone who casts to show you how to do it, because no matter what any of us tell you, actual hands on experience is by far the best.
Best wishes, Gary.

 

[Daniele]

Daniele, the engineering of sculpted figures for casting means going through a period of hard learning that may need some reappraisal of how you are working, what materials you are using and how you use those materials.
If you intend to cast the first thing you need to do is plan out your engineering before you start sculpting and to know how much of a breakdown you need to do, you need to know what medium you are going to cast in (resin or metal).
If resin, you can get away with fewer breakdowns because the rubber for resin casting is much more flexible and has better tear strength whereas the rubber for metal casting needs more breakdowns because the rubber is stiffer and less flexible and will not take undercuts.
Personally, for sculpting I find polymer clays a bit too fragile for multiple part sculpts and I prefer to use a two part putty (for choice MagicSculpt), but everyone has their own favourite.
Everybody has their own working methods, but I prefer to do the engineering at the armature stage and get the joints done first, that way I don't have to cut the figure up afterwards.
The best thing to do if you can is to get someone who casts to show you how to do it, because no matter what any of us tell you, actual hands on experience is by far the best.
Best wishes, Gary.

Gary, your answer was very useful and kind.
Only experience and attempts helps me.
Thank you very much

 

[Daniele]

This is the piece i want to mold casting.

I read about two type of mold casting: one part and two part.

I'm wondering what is the best way to casting this one.
Obviously, one part is more simple.
Can i try? What do you think?

 

[Daniele]

I read about to use some GS around the problematic areas, to use one part casting.
What do you think?

 

[Mark Dollery]

Hi Daniele,
I would youtube casting & silicone moulding to give you some good ides on what to do. I do some personal casting for myself & club members & made my own gear...
Your figure looks to me as it would be a candidate for 2 part casting for better definition & better castings.
(I am only a casting enthuiast not a producer!! )
Mark D

 

[Gaudin]

Separate visor and both hands (wrist level) holding whatever it is he is holding. 3 part.

 

[Daniele]

Separate visor and both hands (wrist level) holding whatever it is he is holding. 3 part.

Oh, around wrist area there are metal armature... i prefer not use hacksaw.
Any alternative?

 

[Gaudin]

Some sculptors/ casters can fill the empty space between parts with a thin layer of putty that will be cut out on a casting, that way you make it 1 peice.

Yours isnt too complicated, so may be there will not be many issues.

 

[Daniele]

Some sculptors/ casters can fill the empty space between parts with a thin layer of putty that will be cut out on a casting, that way you make it 1 peice.

Yours isnt too complicated, so may be there will not be many issues.

I think i'll do it. Thanks.

 

[garyhiggins]

Daniele, I don,t know how many casts you want to make, and with polyeurathene resin the moulds only last for about 30 casts anyway, but you could make a three part mould. I assume you'll be pouring in through one foot and letting the air come out of the other, so make a mould half for the back of the figure with the parting line coming up to the hammer, then make a second (front part) mould half from the head to the arms and hammer, and a third (front part ) mould half from the arms and hammer to the feet. This will be the safest way to get casts cleanly out of a mould. You probably won't want to use this method because it sounds complicated, but it is worth thinking about.
Best wishes, Gary.
PS The visor will have to come off anyway .