Moldmaking Cheap mold alternative to silicone

I have used a similar product called Gelflex. Like you say it would be okay for junk casts and one-offs, and has the benefit of being recyclable; you can melt it down again and use it for another mold.

Resin radiates heat as it cures (exotherm) which may affect the surface of the Vinamold/Gelflex where it touches the hot resin.. it may even deform the mold a little.

 

Wow this is nifty! I really am not planning to make all that many dolls( maybe one or two or each one i sculpt), you can cast a sd size in it? how much do you need for a whole doll? it looks like wax like the type you'd do lost wax casting. and i'd love to get information on gelflex if you could. thanks for posting this

 

hey Twigling,

what did you melt your Gelflex in? if I read it right, you need to heat the vinamold to 350 degrees? that can't be right.... that would burn the clay for the original.

ok - got to go back and re-read the pages again....

 

Pat, 350 fahrenheit perhaps?? If you are claying up your original for a two part mold you can't use plasticine or any sort of clay that will soften and melt when heat is applied. I learned that the hard way. Gelflex (I used the "natural" variety, which refers to the colour) melts at around 170 degrees celcius, and you should let it cool a little before you pour. If you're doing a two-part mold, make sure the second pouring isn't too hot, otherwise it will melt the first pouring where they touch and they will stick together. If poured at the right temp the first and second pouring will not stick and you don't need mold release between them (but probably still good to use some on the part you're molding). Kaye also tried casting with it, and I believe she said using mold release made it stick more, but I'd have to check back through the old email correspondence.

I used a normal cooking pot (never used for food again) on a cooktop (also never to be used for food again) and a wooden stirring tool. Also a digital thermometer to keep an eye on the temperature so it wasn't getting too hot. The thermometer kept konking out because it couldn't handle the radiating heat. Gelflex is really sticky when hot, but as it cools you can peel it off whatever you've got it on very easily. I worked outside or if raining, in the garage with the rollerdoor open. To recycle the mold I would use a heavy duty pair of scissors to cut it up.

 

I really love the idea of being able to cast OOAK bjds --- and so the reuseable mold stuff is really seductive. hmmmmm --- have to get an electric burner and a cooking pot and a digital thermometer...

did you like what you got from it, or did you decide you were better off making the standard silicon mold and just putting up with having to buy more?

I'm such a klutz that the hot thing worries me a bit....

 

It really didn't work out for me, Kaye was using the molds for resin, but I did junk casts in plaster to check. It being my first foray into moldmaking may have had something to do with it. Kaye ended up making a tinsil mold instead though, since the material was breaking down too fast, I'd say that was from the exotherm heat of the resin.

It's no hotter than doing your cooking, and you can wear protective gloves when you are handling. I have burned myself more in the kitchen than working with this stuff, and it's great for practise and junk molds since you can just chop it up and remelt it. As for a one off doll I'd be less certain because you still need to make test casts (use plaster to preserve the mold) and may need to recast parts that don't turn out.