Scotty03´s Noob Iron Man project thread

[Scotty03]

Re: First Mold/Cast - iron man

Hi

I will be molding with rtv silicone and casting in plastic resin. Any of the halo helmet molding videos i have watched just seem to cover the whole thing with multiple layers of silicone. Cut a zig zag through the raised mohican and remove the mold as one part.And then locate in the mother mold. This was my intention.

thanks for getting back to me.

 

[Scotty03]

Re: First Mold/Cast - iron man

Thanks very much for the reply.

So the two part mold refers to a 2 part mother mold with dividing wall?

Unfortunately i have already bought the silicone but am assured it is good quality. I have tested a small part on the chavant clay and it seemed to peel off easily after curing. The only undercut is the chin area so do i have to treat this area any differently?

Thanks for the tip on the casting resin ill definitely check that one out.

I suppose if i make a pigs ear of it my model will remain semi intact anyway!

Scott

 

[JPolacchi]

Re: First Mold/Cast - iron man

I think you definately need to make at least a 2-keyed mold. Be sure to seal your sculpt before casting RTV siicone,the sulfur in the clay could cause real problems, so a nice glossy clear coat will do you some good unless you know for a fact that the oil based clay you are using is "sulfur free".I'd mix a very small batch and paint a thin layer of silicone on,then mix up a larger batch and use a thixintropic agent to thicken the silicone up(you don't have to) you'll just use more silicone.When you pour&cure the first half of the mold(be sure to use a good release agent and repeat the same process on the other half,then you'll have two perfectly keyed molds.You can pour in urethan resin.My suggestion is that you do a slush casting.Do a few successive urethane pours to build up a good shell,then pour in some urethane expanding foam to keep your castings "lite",otherwise a solid casting will be extrememly heavy.There is no one way of doing things,and I'm sure others will have more suggestions if not better ones than me?

 

[SUPERprops]

Re: First Mold/Cast - iron man

^what he said, but if you ever plan on wearing it do Not put the foam in it.

 

[Scotty03]

Re: First Mold/Cast - iron man

Food for thought. Thanks folks

 

[JPolacchi]

Re: First Mold/Cast - iron man

I didn't know it was suppose to me a mask/helmet

 

[Scotty03]

Re: First Mold/Cast - iron man

I just wanted to try a casting of any kind. I may try both now! Thanks for your advice it was all very helpful.

 

[SUPERprops]

Re: First Mold/Cast - iron man

Your welcome, for some pics on the molding process I was talking about veiw my Cad Bane bust thread.





Edit:I think theres more pics in the thread on TDH.com but there's one in here:
http://www.therpf.com/f9/cad-bane-bust-update-first-cast-02-9-10-a-76232/

 

[Scotty03]

Silicone Curing

Hi folks

wonder if anyone can advise me. Did my silicone molding on helmet about 8 hours ago. Some seems to be cured but other parts are VERY moist. Is this normal.(i know pack says 24 hours but there is no difference in thickness between cured and uncured parts?) I am worried i may not have mixed well enough on last coat! Using RTV silicone rubber. If worst comes to worst what can i do about uncured stuff so i can get mother mold on?The vast majority of it seems ok by the way.


cheers

 

[Contec]

Re: Silicone Curing

are your helmet made from clay? did you use any clay to make the mold? If so what sort of clay is it...

 

[Weequay]

Re: Silicone Curing

When you say 'coat' are you appllying layers using a thixo?

As said, what type of clay are you using?

weequay

 

[Scotty03]

Re: Silicone Curing

the clay is chavant non sulphur. I put on two coats then two thickened coats. I ran out of catalyst so used thixo with remaining silicone to fill some gaps.Not a good idea it would seem! I think i may get away with scraping the uncured bits off.

 

[falcondesigns]

Re: Silicone Curing

wait the 24 hours.......there are no short cuts in casting.

 

[Scotty03]

Re: Silicone Curing

yeah its pretty much 24 hours now. ill leave it till morning now. Is there a chemical that can be used to remove uncured stuff if necessary? Its only a few patches here and there

 

[falcondesigns]

Re: Silicone Curing

No,scrape off as much of the uncured stuff as you can,mix a small batch of new stuff and slap it on,and wait the full cure time.

 

[Scotty03]

Re: Silicone Curing

many thanks

 

[fettster]

Re: Silicone Curing

You can clean off the un cured silicone with white spirit, heptane or naptha ( lighter fluid)

Always be meticulous when mixing catalyst. It would eventually gel as it would absorb the moisture from the air but it could take weeks

 

[Scotty03]

Re: Silicone Curing

Ha ha it worked yes! now for the mother mold.

 

[Scotty03]

roto-cast resin and latex

hi folks

is it possible to use smooth on roto cast in a latex mould? I have built up about 20 layers including cloth reinforcement. The mould is a helmet piece and will be enclosed in an appropriate mother mold. Its my first time trying so i dont want to stuff it up. If i get one cast brilliant,more even better.

thanks

 

[JPolacchi]

Re: roto-cast resin and latex

I'm not sure what urethane resin will do to a latex mold? It might really attack it.You could try it, but I'd use a really strong mold release.I can't guarantee the results...it could be a disaster.Silicone is almost always the best bet.