Core "Problems"- Can we help?

Wouldn’t a hollow core lend itself to a far greater chance of major shipment damage?

How about a “Foam” core instead, I don’t know if this would be possible since I don’t know what the molding process exactly takes. I know some materials when setting would just eat through the foam, if not earlier as in the pouring. But there are also multiple diferent “Foam” compounds available so that maybe one of them might work.

My main idea was of a pre-formed foam core blob suspended inside the mold as the sculpture is hardening around it.

Maybe if you find the right foam it may also cut down on the drying time aswell.

Just a thought to try and help you guys out. I know we all want SK’s asap. And again don’t know what you may have tried already. Hopefully though we forum members may be able to give you a few new ideas to try, I’ve grown up seeing first hand that sometimes it’s that fresh perspective that helps.We’ve tried a few different approches: We’ve tried a cast-in-place foam core..disaster. We have tried rotational molding, no good. We have tried an elaborate system of wax filled bladders… that was a big mess. I want to try my idea next, which would be a core (possibly blow moulded plastic)that we could leave in place, as you suggest. Our biggest problem is that we just have no time to work on it! We will figure it out eventually, and your ideas are welcome, Thank you so much for thinking about this!

Can I have the disaster?

I take that back, that was an experiment in packaging them for shipping. It had foam patches stuck all over it. I still have that dragon, she is one of my sample Emerald peacocks. I painted her after the foam incident.

I’d been visualizing a flexible rubber mold for a shape inside, just like the molds on the outside. Maybe one that you poured water into to give it support and shape, and then when it’s hardened you dump the water out and pull the mold off from the inside.

Is this stupid of me, or do some molds actually work like that? For some reason I thought they did.

That was the theory behind the wax filled one. Water wouldn’t work because it is lighter than the liquid gypsum, and would just be pushed up out of the inner mold. Wax would be rigid, then get melted somehow, and poured out after the piece sets.
What else could fill an inner mold and be poured out… Ball bearings? Sand? those are too heavy…hmmm

melody, i have tried something similar and it worked really well….you remember my anthro leafy deer from my ebay profile? he’s hollow! now,he is the original so i haven’t tried it casting wise, but it still may work for you..anyway, when i started sculpting him i knew i need an armature but i wanted it movable so i didn’t get locked into a particular shape…so, i used old, scrap, shredded oil based clay in a plastic bag with the basic shape of the piece and sculpted over it with a synthetic water based/air drying clay. sounds rough but boy did it work great! the oil based clay in the bag was firm enough to hold the specific form i wanted, but since it was shredded, it had juuuuuuuust enough give to where i could squeeze the whole piece carefully to change something slightly if i needed to as i worked on it. once the piece was done and totally dry, i flipped the piece over, where the bottom was open and i removed the shredded clay from the bag and there u go, a hollow piece. the oil based clay was easy to remove as it was shredded so it came out in wads and bits, so no scraping or melting was needed.
of course you will have a different situation casting, as you will be starting from upside down, so the clay could work, or like u said, sand, but then the shape won’t be too controllable. whatever you enclosed it in, mold release would help it come out easy, but i think the biggest issue would be that whatever filler you use will be heavy and i would think the mold/mold jacket would have to be sturdy enough to support its weight. you know, with cross bars or something attached to the bag/insert, resting on the opening of the mold. something like that. could you sculpt a foam insert and put that in a bag or cover it in silicone for easy removal? in college we sculpted expanding foam.. you spray it in a box, wait til its set, peel the box off and carve away. you could do that with a block of hard foam too, but that is harder to find. the foam would be much lighter in regards to the mold supporting it, but it would have to be locked in place so it didn’t float, aaaaand it would be rigid, so it would have to pull out easily… but that is ideal as you don’t want to spend all day finagling/scooping the inserts out of the castings!
anyhoo, those are my ideas, some of which worked for me and may help you, or at least get some creative juices flowing! 😀