Help! How should I mold my mask.

Discussion in 'Sculpture and Makeup Effects' started by Wolf Trait, May 30, 2015.

  1. Wolf Trait

    Wolf Trait New Member

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    I sculpted myself a mask on top of a plaster face cast I made but I have ran into a problem. The ears make it difficult to make a simple jacket mold and I'm not sure how I would make a box mold for it. I could really use some ideas on how to make a mold for the mask. Also I could use some pointers on how to smooth out the mask and make it look a bit cleaner.
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  2. Wolf Trait

    Wolf Trait New Member

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    So I decided to go with a two part box mold. The only problem I'm running into is that the mask I sculpted is made of non drying clay. The only way I know how to make a two part box mold is by embedding the item in clay. I could really use some help.
     
  3. Mr Mold Maker

    Mr Mold Maker Sr Member

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    A box mold would be a colossal waste of silicone to cover the piece thoroughly.

    Why not do a brush up mold? If you're not too familiar with the molding processes, a simple Rebound 25 brush up jacket and a plaster bandage shell would work fine at half the cost..Silicone is very expensive..
     
  4. Sinned

    Sinned Well-Known Member

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    Yeah, definitely not a box mold for a mask like this. Do the brush-up, as Mr Mold Maker says, and then slush cast the mask. Even if you did do the box mold, I don't think you'd get a very good result when casting.
     
    Last edited by a moderator: Nov 8, 2018
  5. Wolf Trait

    Wolf Trait New Member

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    That was my initial plan but I am unsure how I'm going to get the back of the ears. Would I just brush that up and try not to spill while slush casting or try and fill in the ears after?
     
  6. frosty

    frosty Sr Member

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    i would do a plaster mould, a one piece mould, you'd loose the back of the ears but you could add them in after you got the mask out, thats assuming you want a latex mask?
     
  7. Wolf Trait

    Wolf Trait New Member

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    At the moment I have OoMoo 30 from smooth-on that I got a while back. Would this work for the jacket? Also, I was thinking about casting in plastic but am now wondering if it would be better if I used Latex now that it's mentioned. Sorry, I'm still fairly new at this. Made the mistake of making my mask a bit too difficult to cast.
     
  8. Mr Mold Maker

    Mr Mold Maker Sr Member

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    Oomoo would be fine, but you can't use a thixo with it. You need to add cabosil or another inert filler to thicken each layer after the detail coat.

    Resin will be fine, just be careful when you slush cast it.

    If you make a stone mold to cast latex as Frosty suggested, you'll have to do it in two pieces or lose the back of the ears.
     
  9. detenten

    detenten Active Member

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    Oomoo might be frustrating for a jacket mold. I found it kind of crumbled as far as silicones go-- personally I prefer stretchier rubbers for molds that have "glove" parts like your ears (since you've indicated you want to cast both the front and the back of the ears). Rebound will be a little stretchier and less likely to tear; Dragonskin is my favorite because I'm lazy and tend to keep a gallon around for its all-purpose uses (since it's good for both prosthetics and mold making) but it's also a lot more expensive compared to other rubbers that are cheaper and will make molds just as fine.

    If you do latex casting in silicone, make sure you're doing REALLY THIN layers or it'll never dry!
     
  10. Sinned

    Sinned Well-Known Member

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    If you can get some Rebound, rather than Oomoo, I think you'll be happier. The Oomoo will work, but it has a very low tear strength. For this application, your mold will last longer if you use Rebound/Mold Max/etc.
     
  11. Wolf Trait

    Wolf Trait New Member

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    When I slush cast would I be able to add multiple layers of resin?
     
  12. Wolf Trait

    Wolf Trait New Member

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    Never mind. Dumb question.
     
  13. Sinned

    Sinned Well-Known Member

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    Absolutely! And, actually, you will have to. If you try to do it all in one go, you'll wind up with a giant gob of resin somewhere, and thin spots everywhere else. I used to use smooth-cast 300 for masks, but switched to smooth-cast 65D about a year ago. Kind of depends on what you're going for, but the 65D has just a little bit of flex to it (not flexible, but has some give), and overall isn't quite as hard. 300 is much harder, but I found it to be somewhat brittle, for masks, because it is so rigid. With 65D, I don't worry so much about what will happen if I drop one.

    I'd start by doing 4 layers, and see where that gets you, thickness-wise. You'll have to play with the portions a bit, but with a mask this size, here's about how my process would look:

    Layer 1: 1.5 oz of each part A and B, coat the entire mask as even as possible, and then favor one side, as it's about to set up
    Layer 2: 1 oz of each part, coat the entire mask as even as possible, and then favor the other side, as it's about to set up
    Layer 3: 1 oz of each part, coat the entire mask as even as possible, and then favor the middle (top and bottom), as it's about to set up
    Layer 4: .75 oz of each part, coat the entire mask as even as possible, and then favor any obvious thin spot, as it's about to set up

    I wouldn't do a layer with more than 1.5 oz of each part (3 oz total), otherwise you'll end up with an overly thick spot.

    I always tint my last layer a dark black, so I can be sure of good coverage around the whole mask, and also when I demold it, I can see any spots which were thin, from the front, which helps me decide how to refine my slushing process down the road.

    Also, don't let the resin fully cure between layers. As soon as a layer has set up, and no longer oozes, start mixing the next layer.

    It's hardly an exact science. Even with masks that I've made around 100 pulls from, the portions I use, and how I do it varies, just due to how things move around, they're never the same. So you just have to adjust as you go, but good to have a general plan of attack. Your process will be slightly more interesting with the ears, but the overall idea is still the same.
     
  14. Mr Mold Maker

    Mr Mold Maker Sr Member

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    Just out if curiosity, what do you mean the silicone "crumbled?"

    I take many issues with Smooth-On's silicones, but as far as 1-1 Tin silicones Oomoo is one of the best out there. While I don't prefer it, when I've had to use it it has always performed well.

    Did you use a silicone that was past its shelf life?
     
  15. Wolf Trait

    Wolf Trait New Member

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    I'm looking at the rebound 25 now and have more questions. Is there a big difference in 25 and 40. Also, when making the Mold do I still need to buy a thickener even though it's "self thickening"? If so, what kind. Also, would the trial size suffice to making the mold. If not, is there anywhere I could get a bigger amount that won't cost me a near $200. And one more question about the mother mold. From the pictures I took (I could take more if needed), would I be able to make the Mother mold a one piece or would you recommend making it a two or three piece Mother Mold.
     
  16. Sinned

    Sinned Well-Known Member

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    Oh, one more thing on the slush casting. Doesn't matter how careful you are, you're going to get surface bubbles. To fix that, keep a toothpick handy. Once the first layer has completely set, go around, and carefully pop them all. Then, when you do the second layer and slush it around, you'll notice that the larger bubbles now have air trapped in them again. Use the toothpick again to poke that air out, and you'll wind up with a much nicer final surface.
     
  17. Sinned

    Sinned Well-Known Member

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    If you go with Rebound, I'd use the 25, as it's much more flexible. Yes, you will still need a thickener, a small bottle of Thi-Vex will go a long ways. It is still necessary to thicken the silicone after the first or second coat, in order to fill undercuts. Hard to say for certain, but to me, it looks like you should be able to do the whole mask with one trial size kit.

    I'd defer to Mr Mold Maker for best materials to use, and the shell. But I'd use the Rebound, or mold max, and miiiight consider a 2-piece mother mold, just due to the shape. With the snout protruding, and the ears sticking up, you might get it locked in there. Or, might not. Kind of depends on what the final shape of the silicone mold looks like.
     
    Last edited by a moderator: Nov 8, 2018
  18. Mr Mold Maker

    Mr Mold Maker Sr Member

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    Sinned is absolutely correct.

    I believe locking would be a huge issue.. you basically have the snout and ears acting as giant keys against each other. Ideally, you'd do a two piece jacket, separating at the mid point of the ears, so that the piece can be lifted straight out of the mold.

    There are very many options for shell materials. Too many for me to list here. Depending on your budget, amount of casting desired, and skill level I can certainly help narrow it down.
     
  19. detenten

    detenten Active Member

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    I wish I still had the Oomoo mold to send pictures but I angrily chuckled the it after I was done with the order. I might have expected too many pulls from it--I made about 80 little resin medallions out of it, which is probably a respectable number. By around pull 40 I was getting little sheared pieces of purple stuck in the details of the castings. It finally died when the whole mold actually split in two during demolding.
    I used release for every casting and let dry, but I'm sure some rounds were less greased than others.
    More or less I might have picked the wrong rubber for that number of castings. In conclusion: I didn't like it as well, and when buying trial sizes from Smooth On, it isn't dramatically cheaper (or wasn't at the time, I haven't looked at it in over a year).
     
  20. Mr Mold Maker

    Mr Mold Maker Sr Member

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    detenten Oh OK, that absolutely makes sense. I thought you meant you had made a fresh mold and it was crumpling. 80 castings is actually fairly good for a tin silicone mold.. If you use a hotter kicking resin, you can expect even less than that sometimes.


    Smooth-On's tin silicones aren't too great IMO... But that's a story for another day. If you have the extra money to spend, Rebound would be great.... Overkill for your purposes if I had to guess, but definitely advantageous over Oomoo... If not, as I said, the oomoo would be fine. :)
     
    Last edited by a moderator: Nov 8, 2018
  21. detenten

    detenten Active Member

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    Yeah, it was my first break from using (and wasting sooo much $ on) Dragonskin molds, so I was completely spoiled by the time I ventured over to Oomoo!

    - - - Updated - - -

    Assuming your mask is scaled to fit a human face, I think one trial size will definitely cover it for you.

    I personally haven't used thickener with Rebound and have had success all the same.
     

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