Question on Oil-Based Clays

[Slukaj]

I've been messing around with oil-based clays for a while now, specifically Roma Plastilina, but I've hit a wall.

I know that the best way to make a hard version of the sculpted item is to cast the clay using a silicone and plastic combination, but I'm in a situation where that is unusable.

I am trying to sculpt a 1/35th scale Strider from Half-Life 2, and I'm using styrene rods as the legs with clay built up around the joints. The main body itself is made of the clay, as well.

The problem is that due to the strider's spindly structure, I can't successfully mold him using traditional Silicone rubber molds, and therefore cannot make a normal recast as I would like.

My only alternative is to harden the clay. But oil-based clays are supposed to never harden, hence their appeal to modelers. So, my question is, is there any way to harden oil-based clays through anything like topical chemicals, heat, paint, resin, etc.

Here is a strider for your reference:

Thanks in advance!

 

[TheHeroOfCanton]

Well I'm not sure exactly how to advise you on this particular problem, but for your future projects might I suggest you try sculpting in a polymer clay such as Sculpey Firm, Super sculpey or Fimo? They are really nice to work with and only harden when baked at 60+ degrees celcius. I sculpt using them alot and while I'm working I use a heat gun to "half bake" the model so I don't end up squishing details or leaving finger prints. I then give the model a final bake at low temp when I'm done. You can smooth it beautifully using white spirit while un-baked or sand it when hard, and as I said it stays workable forever until you bake it.

I hope you're able to find a solution to your current problem I'm sure people will have good suggestions.

 

[Slukaj]

Well I'm not sure exactly how to advise you on this particular problem, but for your future projects might I suggest you try sculpting in a polymer clay such as Sculpey Firm, Super sculpey or Fimo? They are really nice to work with and only harden when baked at 60+ degrees celcius. I sculpt using them alot and while I'm working I use a heat gun to "half bake" the model so I don't end up squishing details or leaving finger prints. I then give the model a final bake at low temp when I'm done. You can smooth it beautifully using white spirit while un-baked or sand it when hard, and as I said it stays workable forever until you bake it.

I hope you're able to find a solution to your current problem I'm sure people will have good suggestions.

Thanks for responding!

I've considered using polymer clays (and I actually have some around), but the only problem comes from the styrene rods.

I vacuum form Styrene alot, and I know that it takes a good amount of temperature to cause it to flex, but my concern with oven baking the strider is that even with low temperatures, I'm afraid that the legs will flex alittle bit.

I'm keeping oven-baking as a suggestion, but if I can find another mechanism to harden the clay, I'll probably take it over this.

 

[Firefoxm31]

we used to spray it with lots of coats krylon clear forming a plastic layer hardening to a shell like appearance and feel

Will

 

[morrris99]

Why don't you just cast everything separately? Make molds with silicone rubber for the individual legs, then make one for the body. As for the long spindly legs, embed a long brass rod before you pour resin into the mold. It works like rebar in cement and strengthens the long skinny stuff. I can't tell what the bottom of the body looks like, but if you have a lot of hoses take them off, make the mold, then add all your details later. You'll have to drill out mounting points for the legs. Oven baking is probably still the best idea for the clay, but you can coat it with Krylon spray like firefoxfm31 said. You can also coat it with vaseline. You can also just pour rubber around it as is. With sculpey, I would use that as a base for mounting little parts and just pour silicone over it. There were never any curing problems or reactions. Just watch out for fingerprints. Good luck, this looks cool!

 

[Beaker]

look up castilene.. it is a wax/clay mixture used in the toy making industry such as McFarline toys, Sideshow... etc... another thing is Roma is not very usuable with silicone due to the high amounts of sulfur it contains! Try Chavant NSP instead... silicone does well with that oil based clay
Castilene is self supporting! no need for your armatures!