How to make a duplicate of a mother mold

[krisdoce]

Hi there;

This thread is referring to an ultracal 30 mold I created. The mold is of a sculpture my partner created that we are making latex masks with. I would like to re-produce it to increase production but don't want to go though the painstaking task of re-sculpting it. Instead I would like to duplicate it faster using some trick or modern method I have not thought about yet.
I heard somewhere that I could use silicone to do the copy but don't really know how that would work. I think i would risk breaking my original mother mold.
Does anyone here have any experience duplicating a mother mold?

Methods I'm familiar with but would like to avoid:

1st method:
Dry thin layer of latex
Smash water based clay into the details
remove
re-detail
cast.

2nd method:
Dry thin layer of latex
melt oil based clay,
let cool an somewhat harden
carefully remove
re-detail
cast.

I'm open to any experimental ideas or really any help would be great!
Thank you in advance.

 

[HMS Mike]

Do the latex let dry and the pour in flexible expanding foam let cure and then remove from first mold and start making your new molds off the casting.

 

[NormanF]

What about making a casting out of alginate and then make a mold of the alginate?

I seem to recall Steve Neill having to copy a mold of the Whitley Streiber alien bust by packing it with clay a few months ago.
Edit: Found the episodes.
Edit 2: I just noticed he is basically doing one of the methods you are trying to avoid. Oops.

 

[Duncanator]

I'm assuming that the problem is that your original mold has undercuts that would distort any rigid or semi-rigid castings that are removed from it in order to remold them.

I think you already mentioned the solution, and that is to pour up a silicone casting into your ultracal mold, and then make a new mold over the silicone. Silicone and ultracal play nice with one another. The silicone would be able to flex and come out of your mold without damaging any details.

 

[robn1]

Here's another vote for silicone.

 

[krisdoce]

Yes! Thanks guys.
I'm so exited.
I just needed a little backing.
Soon enough I'll have time to post the whole project.
thanks.