Molds,how many pulls?

Discussion in 'General Modeling' started by Drudge, Jan 3, 2012.

  1. Drudge

    Drudge New Member

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    Hi,

    When it comes to molds used by effects studios,how many pulls can they get before they wear out.

    I've always been interested how many casts can typically be produced using the original molds.They're not the typical type of mass production molds that are used in most manufacturing and they usually require very detailed pulls from them.
     
  2. Beaker

    Beaker Active Member

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    That is a huge depends... what is the casting material? What is the original molding material? How was the mold constructed... all these questions come into play before the first question can even be attempted to be answered
     
  3. Drudge

    Drudge New Member

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    Hmmm.... much more complex than I thought:confused.
     
  4. IEDBOUNTYHUNTER

    IEDBOUNTYHUNTER Sr Member

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    we would get 100 to 120 pulls per mold. if you use a mold release with a good silicone. heating the mold to cure resin will lower that number.


    as with any question on here, my answer is only my experience. im sure you will get a wide range of answers.


    Al
     
  5. Beaker

    Beaker Active Member

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    I have seen IEDBOUNTYHUNTER experience but I have also seen only 25 pulls come out of a very good silicone and had some customers say even far less... again, depends on many factors... mold release helps! Mold release is hard to deal with when wanting to paint castings so some go without knowing they will get less pulls... when talking studio when only a few pulls are needed for a shoot, this paintability of a casting might out weigh the number of castings that can be squeezed out of a mold... the type of resin comes into play, a faster setting resin is less chemically harsh on a mold than a slower setting resin... in the same vein, epoxy resins will chew up a silicone mold much, much faster than a urethane resin will (with the above features being mentioned)... Mold complexity, a smooth ball, lets say, will be a lot less mechanically harsh on a mold than a very wildly scaley dinosaur with the mouth open and jagged teeth.... but again, if the mold was properly thought out, the above scenario will do better than a mold that was quickly made and expected to perform... these along with proper mixing and processing of the raw silicone, temperature the molds were made in... any number of things all play a role into the above question that seems simple enough to answer...
     
  6. DarkJedi1500

    DarkJedi1500 Well-Known Member

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    Yeah, there are alot of dependant variables here.

    I typically use rebound 25 rubber and polysester resin you can get at home depot. All the correctly made molds I;ve doon have been going strong. My personal record is 16 pulls from one but the mold is still good, I just didn't have a need for more. On my dalek I will be pulling around 70 cast for the skirt detail, and I have no worries about the mold holding up for this number.

    The only time I have had a mold fail was my first one for the proton packs. I did not know about thickner at the time, so the mold was very thin, particularly around the right angles of the shell. I was able to pull 7 shells before the mold ripped at this point.
     
  7. noble

    noble Well-Known Member RPF PREMIUM MEMBER

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    Having little to no undercuts helps, and applying draft angles..
     
  8. EAGON

    EAGON Member

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    i did a bionicle mask (original toa tahu) and i got perfect casts from it but i only had about 15 pulls till the back side started deteriorating
     
  9. drthomasholmes

    drthomasholmes New Member

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    Fast Catalyst or thixo will reduce mold life, too.
     

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