Stuck Epoxy Blank in 3D Printed Mold

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jbgifford

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Had a friend print a 4 wide mold. Tried it with epoxy resin and now i can't get the blanks out. Tried drilling hole in the bottom for compressed air. I did apply mold release. And suggestions on how to demold would be appreciated. Thanks.
 

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Unfortunately 3D printed molds are not easy to demold, especially with epoxy because resin gets between the print layers (those little ridges you can feel) and it holds on. You can try putting it in the freezer to see if it releases but most likely you'll have to cut your blanks out and ruin the mold. Printed molds aren't meant to be used like hdpe or silicone molds. They are either one time use molds or you have to take other steps to prepare it for use. When I print 3D molds for resin I leave the bottom off and line the inside of the mold with clear packing tape. Then I hot glue it to a flat piece of wood or plastic also covers with tape. This makes it easier to demold, and resin will pull away from the tape easier to reuse the mold (after it cools off). If you try to demold it while it's still warm, the printed walls will deform.
Best of luck!
 
The 3D printer models are good to use for making silicone molds, not casting themselves. Maybe just try 3D printing what you could cast into a custom silicone mold.

I don't like to turn 3D printed items in general, they tend to not turn out as great for me. Just my experience.
 
I have used a torch to soften then the print so I can remove hidden magnets on failed experiments. A few seconds of the torch and the mold will soften, of course this is destructive to the mold.
 
JohnU said:
Unfortunately 3D printed molds are not easy to demold, especially with epoxy because resin gets between the print layers (those little ridges you can feel) and it holds on. You can try putting it in the freezer to see if it releases but most likely you'll have to cut your blanks out and ruin the mold. Printed molds aren't meant to be used like hdpe or silicone molds. They are either one time use molds or you have to take other steps to prepare it for use. When I print 3D molds for resin I leave the bottom off and line the inside of the mold with clear packing tape. Then I hot glue it to a flat piece of wood or plastic also covers with tape. This makes it easier to demold, and resin will pull away from the tape easier to reuse the mold (after it cools off). If you try to demold it while it's still warm, the printed walls will deform.
Best of luck!
Click to expand...
Ugh. Should have done more homework forst. Thank you. Does Alumilite resin fare better than epoxy?
 
jbgifford said:
Ugh. Should have done more homework forst. Thank you. Does Alumilite resin fare better than epoxy?
Click to expand...
I use alumilite urethane in 3d molds often but if I want to demold them instead of turning them off, I coat the inside with clear tape. A heavier tape around 3 mil works best.

Here's a video of my process using 3D molds to cast a small bowl blank. The process is the same no matter how big or small the cast.


When I cast pen blanks, I cast a larger block and cut them to blank sizes. I get more character in them compared to pouring one blank at a time.
 
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And if you're going to make silicone molds from 3D casts, I would suggest sanding them smooth first so you don't have the layered texture in your silicone. The molds will demold easier leading to a longer mold life.
 
JohnU said:
I use alumilite urethane in 3d molds often but if I want to demold them instead of turning them off, I coat the inside with clear tape. A heavier tape around 3 mil works best.

Here's a video of my process using 3D molds to cast a small bowl blank. The process is the same no matter how big or small the cast.


When I cast pen blanks, I cast a larger block and cut them to blank sizes. I get more character in them compared to pouring one blank at a time.
Click to expand...
Well this tells me I've not perused your youtube channel for a while, there are more videos to watch!
 
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