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I want create a small statue with a set of gargoyle\bat like wings that are outstretched, but which curve inwards. The total span of each win will be less than 8" (≈ 20 cm) from base to tip.

Ideally I'd like to cast the wings using a clear two part epoxy resin with a recommended mixture of equal parts by volume A and B, and to color them with alcohol based ink and containing light refracting particles so that they appear to glow when a light is shined through them from embedded LED lights.

I have achieved this effect before with other statues so I know that I can achieve this effect.

My problem is that when trying to cast a thin curved object like this, using a two part mold will A) be very hard to get right and B) require a lot of casting silicon.

I would like to attempt to cast the wings flat, and then to remove them from the mold before they have fully hardened, and introduce the cure manually by bending them.

This would need the resin to be touch dry so that the details are not destroyed when the bend is introduced, but not fully hardened.

I know that this is possible as I've previously accomplished the effect by accident—though I am not certain how. Possibly through contamination or incorrect mixing (cast models sagging, and then hardening to normal levels later on so that they cannot be un-sagged).

Are there any known techniques, such as using incorrect proportions, or mixing in additional chemical agents, that would allow the resin to remain pliable after setting, and then set fully later on?

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    The problem with using incorrect proportions is that this in all likelihood will cause the epoxy to never dry completely or lose its integrity in the longer run. Additional agents will probably do the same (but I'm no expert when it comes to epoxy).
    – Joachim
    May 30, 2023 at 17:00
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    @Joachim, I did it by accident once. The pieces curled up or drooped, but hardened rock solid eventually so I couldn't resolve the problem. May 30, 2023 at 18:30
  • You could reduce the amount of silicone needed to make the mould by supporting it in a form made of wood, roughly approximating the correct shape. This might even make getting it right easier by having reference faces in more useful axes - but that depends how you're making the mould
    – Chris H
    May 31, 2023 at 16:08

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Curing epoxy is a gradual process. It goes from liquid to completely hard in a certain amount of time, but in that time it goes through several stages like goopy, tacky, touch dry and bendy, only slightly bendy and fully hard.

So you can bend any correctly mixed epoxy, but the hard part is finding the right moment to do so and supporting the bent part until it's fully cured. An additional challenge is that any tools you use to bend or support the epoxy can leave permanent marks.

The longer the curing time of the epoxy is, the longer it stays in each stage, so a longer curing epoxy might be better for this project.

This Youtube tutorial shows how to bend epoxy that isn't fully cured.

Another Youtube video indicates that heat can bend a thick sheet of fully cured epoxy.

If I were making your project I would try the heat bending first. It probably takes longer, but that gives me more control. If trying to bend not-quite-cure epoxy, you have to open the mold before you can test the consistency of the epoxy, which is more risky IMO.

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  • I have personally used heat to bend fully-cured polyurethane resin, which has since remained in that shape for over a decade (however, if heated again, would likely return to its original position as it did when I first attempted the bend and had to correct and redo it). It seems likely it would work with epoxy resin as well.
    – Allison C
    Jun 2, 2023 at 13:21
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My suggestion would be to lay out a few layers of Saran wrap, outline the bat wings and pour the epoxy on the plastic. As the wings start to harden, you can pick them up and bend them as you'd like. If you want, use foam or cardboard to make a mold of how you want them shaped and then once they are hard enough, but still pliable, you can lay them over that and they can finish drying how you want them.

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  • How does this keep the epoxy pliable? I think you misunderstood the question :)
    – Joachim
    Jun 2, 2023 at 8:18

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