I am at the casting stage of my puppet-making project and have got some beautiful ball and socket armatures... however i realise that if i just went ahead and cast these in silicone in my mould that it would gum up the joints and it wouldn't move... so..
What is the best way to protect your armature from the silicone seeping into the joints, while still enabling maximum flexibility? :)
Thanks so much for your help xx
Hi there. Two things I've tried in small little tests that worked are:
1) Put a generous glob of petroleum jelly in and around the joints before casting, and it will prevent the silicone from gunking up the works. It can also be easily cleaned out with a small slit and a cotton swab, but will not damage the metal or silicone if left in.
2) sew a nylon stocking fitted to the armature, or at least around the joints. The tighter the better. I made one a little loose, and the silicone pushed it into the joints a bit. Still worked fine, but could have been worse. Something else that could work, but I haven't got around to trying is plastic wrap. Just tape the ends to the "bones" between the joints.
All in all though, if your joints aren't going to be visible (under clothing for example), you can just cast the parts that will be seen and cover the rest in foam or another light and flexible material.
Just some ideas. There are many more people here that would know better though.
I'm actually interested to learn what others do as well.
I've used a little cling wrap around the joints to keep the silicone out. With foam latex, I just use very thin urethane foam, like the sports bandage under-wrap stuff, but silicone will soak right through the foam so that doesn't work.
For clothed puppets I don't use silicone on the bodies because it increases the weight, I just make silicone heads and liquid latex hands, with the bodies under the clothes just built up in cushion foam.
It depends on the thickness of the silicone around the joints, more times than not you don't need to worry about the joints getting gummed up...... do you have pics of the puppet sculpture?
The things I know are used(some may have been mentioned,pardon me for repeating) are:
1.cling wrap around the joints
2.teflon tape around the joints
3. heat shrink tubing using in "electrical wiring" around the joints
4. I've also "considered" the use of a nylon stocking(cut into small strips) and super glued&wrapped around the joints.
PTFE tape is probably the best stuff to use In my opinion, Its so flexible that you wouldnt know it was on the joint at all. You can wrap the whole armature with it. Youll find it in any hardware store, plumbers use it for sealing threaded joints. Good Luck!
Not to high jack the thread,but for "wraping" an entire armature (be it a machined armature or wire),does anyone think wraping/fitting a nylon stocking might give something like "silicone" enough to "grab onto" when casting it in a mold?I've seen some armatures wrapped in string/thread or covered in cotton/gauze.I think that teflon tape is also one of the best things to use to keep casting mediums out of "sensitive" joints/areas next to maybe "heat shrink tubing".Like you said Paul,its "flexible,cheap and easily obtainable at just about any hardward store".
Yes, the silicone soaks into the nylon, and for the most part the viscosity of the silicone is thick enough to keep it from soaking through. To be sure, two layers of nylon is more than enough. I imagine thinner silicones might soak through, but I've only tried this with Dragon Skin 10 Medium.
Using super-glue as you suggested, or even a rubber cement, to hold it together sounds like a much better idea than I had when I tried sewing it together and wrapping thread around the ends. I think a glue would be quicker and easier and better overall.
I still feel like such a novice in this area.Again(not to divert the the subject of this thread),which is the "best" Shore A Hardness of Dragon skin silicone to use?I'm *sold* on using silicone for a variety of reasons(was torn between urethane or silicone for a long time),but not sure how soft of a silicone should be used?Is "firmer/harder" better as opposed to softer and mushy?
We're all beginners at everything before we become experts of anything. I just picked up stop-motion about a year and half ago, after putting it aside for more than ten years.
That said, don't take this as gospel, but from what I've gathered any shore hardness within the Dragon Skin line is good for stop-motion. Which is best for you depends on how strong your armature joints are compared to the shore strength and the thickness of the cast. The higher the shore strength (and or the thicker the skin), the more tension you'll need in the joints to stretch the silicone and keep it in place.
Dragon Skin 10 has proved to be very flexible and forgiving at a thickness under about 1cm. That's from the surface to the armature, and is thicker than needed for most of what I've done so far. For my current puppet, the silicone is only about 1/2cm at the thickest part, and it moves just about anywhere I want it to. I'm considering thinning it down on my next cast though.
Someone else would probably know better, but what I recommend anyway is to get a medium or hard silicone to start with, and also pick up some silicone thinner. The instructions on the thinner will tell you how to determine what amount to use to get a lower shore strength. This way you can experiment to find a shore strength that feels right for you, and in the future you will know exactly what you're looking for.
I'm not sure I want to monkey around much making the Dragon Skin silicone softer than it already comes.With that being said (and what you have mentioned),it appears that at least for "the hands" on my armatures that I should probably go with something on the *soft* side due to delicate joints and how much I can tension them and the body(the rest of the armature) can use something a tad firmer because the joints will be more "heavy duty" for the most part.
again...... pics of the puppet sculpt in question??
I think you'll have to contact Sarah (above) for that.I was speaking "generally" for a number of puppets I've been trying to work out for a while.I'm more or elss narrowing thinsg down.Most my time these days is in drawing/blue prints,designing parts and well..."finding shop space".That's a big one/problem for me at the moment.