Post by carlosanthonyart on Aug 26, 2020 7:45:44 GMT -5
I am attempting to cast a 3d print then make a Latex positive.
I had some success casting in gypsum, then melting the original enough to demold it. However, this means then having to reprint and refinish the print when the cast degrades. This has also only been minimally successful as the mold is not without noticable flaws (crack, chips, etc from stress and undercuts of the plastic)
I have tried making a silicone mold, the mold came out great but latex doesn't solidify in the silicone mold.
Are there any materials that are somewhat flexible, that I can make the mold the pieces in?
First question is which silicone are you using and what latex?
Now as to using a 3D print to make a mold, I agree that having to melt it again to demold is a big pain and you shouldn't need to do that just to get it out. I've used a lot of prints in my mold designs and have never had to do that. I use ABS and have done lots of finishing on them using different things from sanding/grinding to acetone smoothing to simply sealing them with resin. After I've done work on getting the prints right, I would never intentionally remelt them to demold from a mold. Especially since you can simply make cuts in the silicone (where needed) to demold.
Alumilite has a flexible series of resins - www.alumilite.com/products/resins/rubbers/ that work well with demolding from silicones. Just remember that they ARE a resin type and read all the instructions on how to mix and use them. I wouldn't recommend pouring them over the 3D print but they would work just fine as the casting material.
As for the mold itself, I would use High Strength 3 (or 2) as the mold as both are very flexible and #3 is a little "softer" than #2 but both can be stretched to demold without breaking a print without getting out of shape. The High Strength series is flexible but very strong so if you need to make a cut be sure to use either scissors or a knife as they'll stretch way before they tear and it's not easy to tear them.