How do I mold parts with concave lips?

[MrSinistar]

Hi guys,

I have a friend who has a very rare prop part and we're both interested in molding it. However it has lips that fold up on itself and I was wondering how difficult would it be mold it, let alone how do we even tackle molding it?

Here's a picture:

As you can see it's a big part as well and so I figured we should mold it like a helmet. Just brush on some silicone and back it up with plaster or something for the jacket.

Any advice would be appreciated!

 

[Mostly Fantasy]

Looks like a straight forward parting line- pack clay around the edge following the curve, apply silicone to first side, let cure, make mother mold, let cure, flip, pull clay away, clean, apply separator, repeat for second side. Make keys in first 1/2 of silicone.

 

[Ozymandius]

Is that Gypsy?

 

[Maelstrom]

Is that Gypsy?

Looks like it to me

 

[MrSinistar]

Yup. He has two car seat heads...one he wants to keep for prosperity and the other to mold and eventually convert into a Gypsy head. I'm hoping he'll let me borrow one and I can mold it so we can finally get a replica car seat available as this part is really difficult to find.

If anyone has a Century/GM Infant Love Seat and is willing to trade for a Money Lover Barrel or want to go to the good ol' cash route, please let me know.

 

[MrSinistar]

Looks like a straight forward parting line- pack clay around the edge following the curve, apply silicone to first side, let cure, make mother mold, let cure, flip, pull clay away, clean, apply separator, repeat for second side. Make keys in first 1/2 of silicone.

So basically, what you're saying is I would make a "dam" or a barrier for the silicone to build up over the lip and then remove the clay and do the other side of the seat?