Dry clay already molded Advice?

[hunterpred210]

I molded my sculpture and the molds are not wanting to pry off I managed to get it slightly ff in a few areas. A little piece broke so im scared to do any more. Anyone have any suggestions on what I can do? I was thinking of getting one of those inflatable child pools and let it soak in there.

 

[ScottAS]

You have to explain what type of mold and what materials are involved. What is dry clay? Water clay that's dry?

 

[hunterpred210]

I used WEd clay and I think it dryed out a bit. Im using ultra cal 30. I have the mold lifted somewhat I just don't know how to lift it totally off.

 

[ScottAS]

If mold is still 2 halfs together I would use wood shims and apply them around the mold, driving them in a little at a time to force the mold apart. When I make a big mold I use 1 1/2" wood dowels to make handles on the out side that run the entire lengh of ythe mold, plus it reinforces the mold. If you are on the second piece I would dig out the clay to save the mold. Before you cast this did you apply a coat of vaseline for mold release?

 

[hunterpred210]

I did make clay spaces for the screw drivers. I hear it wanting to come off it just won't pop off. Do you think putting a hose over the mold would work andd maybe make it easier to get it off?

 

[hunterpred210]

Well it was a disaster! I think it was just to big of a mold for me to handle. Im going to try and salvag ethe sculpture. The torso is workable. I think it would be best to make each arm seperate pieces and mold them both by themselves. It worked better last time for me when I had everything individul. Its a real shame when you have put so much into something just for it to be destroyed. Since the clay is all sealed ith crystal clear im wondering if rubbing it down with cooking oil would work as a good lubricant so it comes off easier. Im pretty sure I can salvage some of it.

 

[StazztheRed]

I have had this happen to me many times . I would the next time you mold, make sure you have the ultra cal 30 really layered on the clay, and then reinforce them with burlap.

 

[hunterpred210]

Alright take two. I have molded my torso without the arms. Im wndering what is the normal layer or thickness of ultra cal neede. Im not sure if im using too much or not enough? I use about 3 coats.

 

[maverick118]

I tend to go about 2 1/2 inches thick with something like this as it's got a lot more integral strangth as the last three layers i put on a strengthened with Burlap stips and a final layer containing plaster bandages so there ar no rough edges. It'll depend on how strognthe stone is in the thinnest points and how many pulls you intend to make from the mold...If it's a one shot or only a handfull of pulls you can get awy with an inch inch and a hlaf if you're confident with your molding skills and getting the halves to separate....I tned to do any stone molds thick though just to be on the safe side...and don't for get once the molds are separated to take a hasp or plaster file to the egdes as you want to get trid of any excess points and sharp bits...If you're slushing this the less pointy bits to snag on clothes or cut your skin the better.

 

[hunterpred210]

Sometimes I get small cracks in the mold. Should i do something to it perhapes spread epoxy putty over them?

 

[maverick118]

If you runing foam latex that will be cured via an oven the using epoxy to fill the crack should be fine, just be careful of steam pooling...If it's just simple pre vulc rubber then I would shy away from using epoxy as the latex will not cure against it as quickly as it would against stone....When I've had my molds crack or break and if the project was needed in a hurry I would soak the mold pieces in water and then mix a bacth of fresh plaste and use that to patch the mold segments together, soaking the mold segemtns re-hydrates the stone and allows the fresh stone or platser to ahere with out the moisture being leeches too quickly form it, as this will make it prone to crumbling and have very littel integral strength to it....you can even add detail to the freshly drying plaster as it gels so as to hide the fact that the mold went **** up....I've as I said had to do this a few times as sculpting an molding a fresh piece would have been either too cotly or time wouldn't permit it. I would also add a final layer of stone and burlap to re-inforce any repairs made...Just to be safe. I know the molds will weigh a ton and they will be hard to move aroudn if sluching casting in them but the molds will last a good long time if you're careful and wash them properly after use...The will eventually lose detail or in some case the detail coat wil de-laminate from the mold itself, but I've not had that happen in a mold only meant for a few runs Hope this help you out mate.