General Casting Questions

[RollaJedi]

thank you for your help.
I will probably end up getting the RTV stuff.  What do you mean by demolding though?

[tykrazen]

Removing both the original and cast pieces from the mold.

[RollaJedi]

is the original usually hard to take out of the 2 piece mold then?  I mean, it doesnt just fall out, right?

[tykrazen]

If you have used a mold release (a thin layer of vaseline works), it is usually pretty easy to get the piece out with an RTV rubber mold.  You'll kind of bend and twist the mold a bit to get it free.  (Plaster doesn't have that flexibility and hence why it is harder to remove the piece.)

[RollaJedi]

well, I tried using plaster of paris last night just to see what it would do.  Man, I DO agree with you both!!!  That crap SUCKS!!!
I oiled the crap out of my pieces with vasoline, and plaster still stuck to them.  Plus, it was a pain to get the base pieces out.  If I never use it again, it will too soon!

I want to use the rtv stuff now, but it just seems like it costs a lot for how little you get.  What do you all buy, whats it cost, and how long does it last you?  If you dont mind answering.  Thanks!

[BrentS]

I seem to recall that I bought a two part silicon kit that was around $30.  I believe it was the same stuff glassman uses for his 1 piece push molds.

[RollaJedi]

Since I'm following Glassman's tutorial on the other site, I went to the different sites and here is what I came up with:

For one piece molds
smooth-sil 920  $26 for 1 pint trial size (1 pint part a, 1 pint part b) at smoothon.com

For two piece molds
4 hour one-to-one silicone rubber   $31.75 for 16 oz. at micromark.com

For two piece mold (cast)
Polytek easyflo 60    $43.35 at polytek.com (I'm not sure on the size here.  Looked like a gallon maybe?)
or
smooth cast 45D, 60D    $23 for 1 pint of A and B at smoothon.com


So far, I like the 4 hour one-to-one for $31.75 for the molds and the polytek easyflo 60 liquid plastic for casting at $43.35.  About how long would something like this last if all you did were make arms, legs, torsos, heads?  I mean, would I be able to make a lot from this?

Thanks for all you alls help!

[BrentS]

I have the smooth sil 620 and I have CR-300 resin (from micromark).  These supplies will last you a long long time.  The real driving force for silicon two piece molds is the size of your mold box.  The smaller the better so that you do "waste" it.  If you make the one piece pour molds like Glassman recommends, I imagine it will last a long time.  Hope that helps.

[RollaJedi]

yes, that helps a lot!  Thank you!

[Glassman6]

Well i was gonna answer your questions, but BrentS said it all.

THe easy flo will last a long time. A LONG TIME. As long as you arent wasting it.
When i first got the stuff, i was using medicine droppers. So i wasted nothing.
Now a days i eyeball it, casue i'm used to using it. So i tend ot waste a bit here and there.

But it will last you. THe RTV is what i order the most.  If your mold doenst come out right...you've used alot (depending on the size of the box)   
Last year, working on Star wars and Justice league. I ordered RTV 3 times.

Keep in mind, you dont have to use these specific brands. You can get all your stuff from one place and save some shipping. I use these cause i have come to like them for various reasons. But they arnet set in stone.

As for the plaster o paris, I have to say..told ya.   

The mold stuff, will give you problems... and you will end up
not liking it and it will end up sitting there.

Ask me how i knew... Been there. Done that. I've tried many store bought alternatives. The only thing that worked well, was silicone window caulk.

[RollaJedi]

Silicone window caulk?  Did you use that as an alternative for your molds?

Yeah, I kinda hada  feeling that the plaster wasnt worth a poo, but I already had it and was curious.  SO, naturally I indulged myself and ended up nearly encasing a corps! figure in carbonite of paris! 

I'll look at the other brands for the stuff, but I have done this a little and so far what I'd said is the cheapest I think.  I'm kinda wanting to go the more cheaper route right now, until I'm better at it.  Then I can get picky with it. 

Thanks for all your help!  I needed to hear this.  Thanks!

[RollaJedi]

well, thank you guys for your help and advice, but I'm gonna stick to old fashioned customzing for the time being.  I just really dont have the money to start this right now and I dont know how much I'd get to use it since free time is very slim anymore. 
Thanks though, its been very informative if I ever want to try it!

[Ner_vod]

Hey guys,

I'm thinkin of startin to sculpt and cast but I really dont know how to (Except for ceramics and stuff).

what products do you people use and is there a tutorial?

[Smartypants1635]

Well for us beginners I get sculpy.
 It works fairly well. Then I make a mold of it cast it and then revise it a bit with green stuff putty which drys like a rock so its finished if its a one time use, then if not I go back and make a new mold, but since all my customs materials are gone I can't give pics.

[BrentS]

Thats a pretty good overview from Smarty.  Check out FFURG.com they have a lot of great tutorials on sculpting, casting, etc.