Do you seal + release Monster Clay & mixed media before molding with silicone?

[stopmo]

Hello everyone,

I've been working on a 1/3rd scale bust (my first) and I'm getting ready to mold it. I bought a pint kit of Rebound 25 as that seems to be the most often used for jacket molds like this, plaster bandages for the shell and some smoothcast resin to cast it in.

My sculpture is mostly Monster Clay but for the base of the bust I also have 3d printed (PLA) parts and even a metal component (maybe pewter? Not 100% sure). Those pieces are all surrounded by M Clay as well.

My teacher told me to use Krylon crystal clear and then universal mold release on top of the piece before molding. A friend told me the mold release will make the silicone not dry and that M clay doesn't need a sealer because it's wax.

I also spray-painted (Rustoleum) the PLA parts before adding them to match the colour of the clay to make it easier to envision the final form.


There are so many knowledgable people here, if anyone has experience using these materials I would be so grateful for advice.

 

[Mr Mold Maker]

Generally speaking you only need to seal when something is porous or is at risk of inhibiting the silicone. Silicone doesn’t dry, it cures, and how it does that determines if it is a platinum silicone (like rebound) or a tin silicone (like mold max.)

When it comes to platinum cure silicone, they are very sensitive to cure inhibition so you just have to watch out for that. If you’re worried, you can mix up a very small batch and test it on the various materials to make sure it cures. If anywhere doesn’t cure, then you’d want to seal with crystal clear or superseal and maybe even use some Inhibit X, but that likely won’t be necessary for you on this.

Universal mold release is a silicone based release so it’s not meant to be used before molding with silicone. Ease release 200 or 205 would be better options, but generally I do not seal or release monster clay when making a silicone mold. The worst case scenario you may have skipping a release agent is a little bit of the spray paint sticking to the rebound, but that’s very easy to wipe away with solvents.

Hope this helps somewhat.

 

[stopmo]

Hey you helped me with my hair question too! Thank you Mr. Mold Maker, your advice makes me feel a lot more confident.

 

[JPH]

Hello everyone,

I've been working on a 1/3rd scale bust (my first) and I'm getting ready to mold it. I bought a pint kit of Rebound 25 as that seems to be the most often used for jacket molds like this, plaster bandages for the shell and some smoothcast resin to cast it in.

My sculpture is mostly Monster Clay but for the base of the bust I also have 3d printed (PLA) parts and even a metal component (maybe pewter? Not 100% sure). Those pieces are all surrounded by M Clay as well.

My teacher told me to use Krylon crystal clear and then universal mold release on top of the piece before molding. A friend told me the mold release will make the silicone not dry and that M clay doesn't need a sealer because it's wax.

I also spray-painted (Rustoleum) the PLA parts before adding them to match the colour of the clay to make it easier to envision the final form.


There are so many knowledgable people here, if anyone has experience using these materials I would be so grateful for advice.

When I made Green Lantetn mask, I spray painted it with --I believe it was Rusoleum-- and used Rebound 25. The mold came out looking like a burn victim.

Test the clay with whatever you applied to it, on a sample first.

If it fails, you may want to coat your sculpt with something like XTC 3D epoxy in an effort to save it. You can lose detail, so make sure you apply super thin, and flash a light over it to make aure it doesnt pool.

I would NEVER tell anyone to touch resin, but I use my finger on XTC 3D while it is curing to make sure it cures evenly. Wash off with 90% alcohol or mineral spirits. You can develop allergies to resin.

If your sculpt has a lot of curves, bends, bottlenecks, you may want to consider using DragonSkin 10 Fast instead. It captures detail well, and is much more stretchy.

Ease release 205 is what I use, before applying Rebound 25. The first coat of Rebound needs to be applied super thin, and you will constantly have to scoop up the Rebound that has run down the sculpt and reapply it uphill. It will capture detail very well, but make sure *whatever ypu apply* NO BUBBLES in that thin, first layer.

I hope you got some Thivex. Just add a drop per 1-2 oz of Rebound.

Seriously, just a drop per 1-2 oz of Rebound. I wouldn't mix more than 4 oz of Rebound at a time. Too much Thivex and you will have a clump of useless Rebound popsicle

Also, with Rebound 25, I cut little, 0.5 cm pieces of foam to apply for registration points.

Are you going to use FreeForm Air or Plaster for the hard outer shell?

Figure out how you want to demold. It might help to superglue a thin, semi-rigid material to your sculpt, to help de-mold.

 

[stopmo]

When I made Green Lantetn mask, I spray painted it with --I believe it was Rusoleum-- and used Rebound 25. The mold came out looking like a burn victim.

Test the clay with whatever you applied to it, on a sample first.

If it fails, you may want to coat your sculpt with something like XTC 3D epoxy in an effort to save it. You can lose detail, so make sure you apply super thin, and flash a light over it to make aure it doesnt pool.

I would NEVER tell anyone to touch resin, but I use my finger on XTC 3D while it is curing to make sure it cures evenly. Wash off with 90% alcohol or mineral spirits. You can develop allergies to resin.

If your sculpt has a lot of curves, bends, bottlenecks, you may want to consider using DragonSkin 10 Fast instead. It captures detail well, and is much more stretchy.

Ease release 205 is what I use, before applying Rebound 25. The first coat of Rebound needs to be applied super thin, and you will constantly have to scoop up the Rebound that has run down the sculpt and reapply it uphill. It will capture detail very well, but make sure *whatever ypu apply* NO BUBBLES in that thin, first layer.

I hope you got some Thivex. Just add a drop per 1-2 oz of Rebound.

Seriously, just a drop per 1-2 oz of Rebound. I wouldn't mix more than 4 oz of Rebound at a time. Too much Thivex and you will have a clump of useless Rebound popsicle

Also, with Rebound 25, I cut little, 0.5 cm pieces of foam to apply for registration points.

Are you going to use FreeForm Air or Plaster for the hard outer shell?

Figure out how you want to demold. It might help to superglue a thin, semi-rigid material to your sculpt, to help de-mold.

Thank you for the reply! I wish I knew about the dragonskin fast before buying the rebound, sounds like better stuff.

I do have Thivex, I will make sure not to over-use it.

Can I ask what kind of foam you use for registration? Do you stick them in the wet silicone? Do you add a layer of silicone on top of that if so?

I'm using plaster bandages for the shell, I am unfortunately low on money.

For demolding I've planning to follow this smooth-on made tutorial on youtube, they cut a line up the back to take it off.

I do not understand what you mean by gluing a rigid material to my sculpt and how that works in demolding? It sounds very interesting though.

 

[JPH]

Thank you for the reply! I wish I knew about the dragonskin fast before buying the rebound, sounds like better stuff.

I do have Thivex, I will make sure not to over-use it.

Can I ask what kind of foam you use for registration? Do you stick them in the wet silicone? Do you add a layer of silicone on top of that if so?

I'm using plaster bandages for the shell, I am unfortunately low on money.

For demolding I've planning to follow this smooth-on made tutorial on youtube, they cut a line up the back to take it off.

I do not understand what you mean by gluing a rigid material to my sculpt and how that works in demolding? It sounds very interesting though.

I use Rebound for most of my molds. The only time I really used dragonskin was for a demold that needs to be really, really sstttrrreeetttccchhhed.
Like on an alien valve where the internal base is wider than the exit hole. Repund cant stretch and deform that well, but Rebound will get you great detail.

I glue Gorilla tape to the botton of mask molds.
That is the semi-rigid material to the back of the sculpt. I then apply Rebound to the mask, knowing I will use the mold upaide down when I make castings.

Regular, plain ol boring 1/4 inch thick foam

I have threads on green lantetn mask and making a Kosh whwre I talk about this stuff

 

[JPH]

Gorilla tape on Wolvwrine cowl. Also over the eyes, so the mold has a front and back.

Dragonskin for a valve where the demold involves pushing a wide base tbrough the small opening...uae release agent