Rubber Molds & Green Stuff

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  • Steffen

    Looks really effective, how hard is the final cast compared to regular cured green stuff? And btw, isn’t green stuff toxic ?? I surely seem to remember reading several places that it is important to wash hands after using kneadite as the epoxy in it is not very healthy to you? 🙂

    • Seems to be harder than plain Green Stuff once cured.

      Well all epoxies are pretty toxic, but what isn’t these days. Personally, I can’t be using gloves whilst mixing/using this stuff so I am constantly washing my hands (I’m a little OCD when it comes to hand washing).

    • Seems to be harder than plain Green Stuff once cured.

      Well all epoxies are pretty toxic, but what isn’t these days. Personally, I can’t be using gloves whilst mixing/using this stuff so I am constantly washing my hands (I’m a little OCD when it comes to hand washing).

  • Kroottastic

    That’s a rather fine cast. I would not have expected this to come out so well after your previous attempt with the Primarch. I have to say, you inspire me to further my own limited sculpting talents. 

  • Jack Straken

    Impressive, the result looks comparable to what I got with the Sylmasta resin casting starter kit, but without the air bubbles and the hassle of mixing resin that isn’t 1:1. Will you be casting your Primarch masters with this process at any point? I’d love to see if it can pull off a whole leg+torso set  when there’s a few undercuts to worry about.

  • Jack Straken

    Impressive, the result looks comparable to what I got with the Sylmasta resin casting starter kit, but without the air bubbles and the hassle of mixing resin that isn’t 1:1. Will you be casting your Primarch masters with this process at any point? I’d love to see if it can pull off a whole leg+torso set  when there’s a few undercuts to worry about.

    EDIT: Ah sod it, I’ll just get some and try it, the price is reasonable enough.

  • AekoldHelbrass

    How do you think, is it possible to use liquid and firm blu-stuff to make sharper parts with pure green stuff? Making first firm layer with blu-stuff, then filling everything with liquid-blu-stuff to hold blu-stuff from breaking?

  • AekoldHelbrass

    How do you think, is it possible to use liquid and firm blu-stuff to make sharper parts with pure green stuff? Making first firm layer with blu-stuff, then filling everything with liquid-blu-stuff to hold blu-stuff from breaking?

  • alejandrinus

    Did you tried using plaster of paris instead of green stuff to make the cast? Im thinking for scenary pieces with liquid blue stuff.

    • I have and it works just fine.

      Shooting myself in the foot by saying this, but for large pieces you probably want to use a more conventional silicone rubber, simply because of cost. The Liquid Blu-Stuff is best suited to small projects because it can be measured in such small amounts and cures very quickly. Regular Silicone Rubber is always messier to use too.

  • alejandrinus

    Did you tried using plaster of paris instead of green stuff to make the cast? Im thinking for scenary pieces with liquid blue stuff.

  • can the liquid blu-stuff be reused, because it looked like you used a lot there, for such a small part

    • No the Blu-Stuff can’t be reused to make a different mold, although it can be used to make a LOT more of the same cast.

      This particular mold used just 34g of Liquid Blu-Stuff (about 1/6th of the 200g product). The mold could have been made smaller, it’s simply an issue of having the right size container to pour into (Lego is ideal).

      The advantage of Liquid Blu-Stuff over other silicone rubbers is that it can be mixed in such small quantities, with no mess. Regular RTV silicone rubbers require measured amount of catalyst (ie: 8 drops per 100g, or something similar), requiring weighing scales and usually 12 hours to cure.

  • spyke13

    I recently got hold of an old Eldar Harlequin jetbike and tried using Instant mold sticks to cast a duplicate of the canopy for another project. The instant mold did not seem to pick up all the detail. After reading your article, it appears that liquid blu-stuff may make this easier and does pick up all the details too.
    Thanks for writing this article – it’s been a great help!

    • The Liquid Blu-Stuff will definitely pick up the details. I assume it’s the grinning face canopy you’re speaking of. If you do the casts in putty (Mulliput and Green Stuff would be my recommendation, or just plain Mulliput) you should be able to do them with a one piece mold, as the inside of the canopy is generally hidden from view.

      • spyke13

        Yes – it’s the grinning face canopy. I was planning on mixing the blu-stuff and placing the canopy face-down into it in order to get a one piece mold. Would this work, or would I be better in pouring the blu-stuff over the canopy?

        • If you place it into the Liquid Blu-Stuff you risk getting air bubbles on the details. If you go that route you may want to brush the liquid over the details first to be sure it properly covered (be quick about it though).

          If I were doing this cast I’d make a small box from plasticard or lego and put plasticine in the bottom. I’d then push the canopy into the plasticine and neaten it up leaving the face facing upwards.

          So something a little like this: http://masteroftheforge.com/wp-content/uploads/2012/05/moldexample.jpg

          Then pour the Liquid Blu-Stuff slowly, letting it gradually fill up the container, but without pouring directly onto the component. This will make air bubble very unlikely, and give you a one piece mold into which you can push Mulliput or a Green Stuff/Mulliput mix.

          The easiest option would be to do it like I have in the above example, to simply fill the whole container with Liquid Blu-Stuff (with the component inside but no plasticine filler) and cut the rubber mold in two after.

          • spyke13

            The plasticine/box combo looks to be a good idea. As the canopy will be used for a Wraithlord head, the one piece mold would be better as I don’t want to risk cutting through the details in mold.
            I’ll just have to find some lego (shame I sold all mine years ago) and plasticine which should be cheap enough.

          • The Lego I got for my mold box was bought directly form Lego.com and I believe cost me just over £10, probably cheaper than trying to find second hand blocks.

          • spyke13

            I’ll have a look on ebay as I don’t think my younger cousins will be willing to part with theirs 😀

          • spyke13

            I’ll have a look on ebay as I don’t think my younger cousins will be willing to part with theirs 😀

  • spyke13

    I recently got hold of an old Eldar Harlequin jetbike and tried using Instant mold sticks to cast a duplicate of the canopy for another project. The instant mold did not seem to pick up all the detail. After reading your article, it appears that liquid blu-stuff may make this easier and does pick up all the details too.
    Thanks for writing this article – it’s been a great help!

    • The Liquid Blu-Stuff will definitely pick up the details. I assume it’s the grinning face canopy you’re speaking of. If you do the casts in putty (Mulliput and Green Stuff would be my recommendation, or just plain Mulliput) you should be able to do them with a one piece mold, as the inside of the canopy is generally hidden from view.

  • I followed this tutorial to the tee, but my results where no were near yours. Im doing an astral claw forgeworld shoulder pad. any ideas on what i may be doing wrong? should i use a different container instead of the one provided to me by blu stuff?

    • Hmm… any chance you could email me pics of the results you’ve got so far?

      A smaller mold container might be better. I’ll have a go at a shoulder pad myself tomorrow and see if I encounter any problems too.

  • I followed this tutorial to the tee, but my results where no were near yours. Im doing an astral claw forgeworld shoulder pad. any ideas on what i may be doing wrong? should i use a different container instead of the one provided to me by blu stuff?

    • Hmm… any chance you could email me pics of the results you’ve got so far?

      A smaller mold container might be better. I’ll have a go at a shoulder pad myself tomorrow and see if I encounter any problems too.

  • Bob

    Is Magic Sculp the same thing as Magic Sculpt?

  • Bob

    Is Magic Sculp the same thing as Magic Sculpt?

  • matt woods

    Hey mate.  I was just wondering if you could use Green Stuff just by itself, without the Magic Sculp?
    As i am just having trouble getting hold of some Magic Sculp in Australia.
    Any help you could give me is greatly appreciated!

    • Sorry for the late reply I only just realised I’d not answered this.

      Green Stuff by itself will most likely prove to be too firm, and therefore push on the mold rather than the mold push on the putty (I hope that makes sense).

      I’d try Mulliput instead of Magic Sculp, it’s probably more widely available and from what I’ve heard gives the same “softer putty” mix when added to Green Stuff.

  • matt woods

    Hey mate.  I was just wondering if you could use Green Stuff just by itself, without the Magic Sculp?
    As i am just having trouble getting hold of some Magic Sculp in Australia.
    Any help you could give me is greatly appreciated!

    • Sorry for the late reply I only just realised I’d not answered this.

      Green Stuff by itself will most likely prove to be too firm, and therefore push on the mold rather than the mold push on the putty (I hope that makes sense).

      I’d try Mulliput instead of Magic Sculp, it’s probably more widely available and from what I’ve heard gives the same “softer putty” mix when added to Green Stuff.

  • Great article, and pretty much what I needed for my own conversions. Quick Q: Is it worth wrapping the mould in a rubber band overnight, or do you just leave it be?

    Cheers!

    • Yeah that’s certainly an option. I like to push the mold back into the container I made it in as then it pretty much has to conform to the correct shape. But a rubber band would work too.

      The main thing is getting the amount of putty used for the cast just right. You can often check after you first squash it in there and you’ll be able to tell if there are gaps in the cast (too little) or a lot of flash (too much).

      Of course because it’s putty you can just take it out, adjust, and squash it back in.

      I’ll have some more examples soon, as I’m tempted to cast up my own collection of Truescale Space Marines using this method and really test how far I can take the material and figure out potential problems.

      • Thanks for the reply. One more thing I forgot to ask last night: You obviously don’t cut the whole way through the mould, but how deep is the cut? About 300 mm from the bottom end enough?

        • No problem.

          The thing about the cutting is that it is totally dependent on the part and size of the mold (300mm? typo right?).

          You could just cut right through and make a 2 piece mold but then its more problematic to align afterwards.

          When I make the cut it isn’t just one deep cut and done, but a series of gentle cuts, all the while teasing the two halves apart.

          It’s not easy to describe accurately so I’ll try and make a video soon. Really you’re just trying to open it up enough to get the putty inside, the smaller the cut the better.

          I think some people are struggling in finding where to cut too. As long as the mold isn’t too chunky you should be able to feel the edges of the component in the mold when you squeeze it. Then it’s just a bit of guess work. Wherever the cut is located will determine where your mold line will appear on the cast.

  • Great article, and pretty much what I needed for my own conversions. Quick Q: Is it worth wrapping the mould in a rubber band overnight, or do you just leave it be?

    Cheers!

    • Yeah that’s certainly an option. I like to push the mold back into the container I made it in as then it pretty much has to conform to the correct shape. But a rubber band would work too.

      The main thing is getting the amount of putty used for the cast just right. You can often check after you first squash it in there and you’ll be able to tell if there are gaps in the cast (too little) or a lot of flash (too much).

      Of course because it’s putty you can just take it out, adjust, and squash it back in.

      I’ll have some more examples soon, as I’m tempted to cast up my own collection of Truescale Space Marines using this method and really test how far I can take the material and figure out potential problems.

      • Thanks for the reply. One more thing I forgot to ask last night: You obviously don’t cut the whole way through the mould, but how deep is the cut? About 300 mm from the bottom end enough?

  • Brandon Burt

    Smells the same -shrugs-

    • It’s a good indication that the materials use the same chemicals. At least that’s how I see it.

    • It’s a good indication that the materials use the same chemicals. At least that’s how I see it.

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