3d Printed Molds for Plaster or Concrete - Boil Molds

Casting plaster in 3D printed molds is tough, often it's very hard to extract the model from the mold without breaking it, even if you use generous amounts of release agent.
The demonstrated method is to 3D print a very weak 3D mold, cast the plaster in the mold, then boil the mold to make it soft and thus make it easier to release the model.
Also demonstrated is casting a mold that can be used to cast clay figures - a slip mold.
[This video was previously posted on my Grobian account that's primarily for Machine Learning related stuff, so I moved it here.]

[@emilyblythejones]

I’m eager to try out this technique at some point. I’ve found a reusable silicone substitute in the form of making agar molds that are beautifully compatible with plaster. After demolding, the agar can be remelted to make subsequent molds. I usually can only get one casting out of the molds but I love being able to just re-melt the mix. The other recipe I use is less compatible with plaster and better for water based clay, but you can get multiple castings from each mold and then also remelt the material for subsequent molds - this utilizes glycerin and gelatin. Thank you for sharing your techniques, I’d love to be in touch!

[@grantclark4139]

Thank you for your tutorial. I'm looking at this method for casting a component for a project, and had no idea how to work with plaster. You have saved me a lot of time and pointed in the right direction!

[@mattiasfagerlund]

Nice, let us know how it goes!

[@infocus-media]

My wife has one of those vibrating machines you used to get the air out, I always wondered what she used it for, now I know, Thank you for showing me. LOL!

[@paulakafish]

Nice video, I enjoyed it a lot. I will try some of your suggestions to improve my 3d printed molds for plaster and concrete. I look forward to your new videos.

[@malcolm7436]

I would love to know about how you use a core to avoid undercuts and to create a hollow.

[@codyrubino5715]

Great tutorial . Lookin forward to the next one on cores. Please keeps it going !

[@deaultusername]

You ever try "firing" the clay casts in a Microwave Kiln, the plaster outer case with a layer of Silicon carbide on the inside. The Silicon carbide absorbs the microwaves and heats whats in the kiln. they are usually used for glass.

[@mattiasfagerlund]

I haven't, no, but I have considered it. They seem rather small, though?

[@robinlaurenssen2741]

Very nice video!

[@andregois7926]

Very good

[@Anton-zb9dc]

To dry plaster mould you could use microwave

[@ginger---]

Is it okay to pour and make a mould on a 3d print plastic directly for ceramic clay?

[@mattiasfagerlund]

You can make press molds in plastic but plaster is used for liquid clay because it de-hydrates the slip and hardens it around the edges. Slip in plastic molds doesn't harden the way you want it to.

[@ginger---]

@@mattiasfagerlund Now I understand! Thank you

[@julian_loewe1977]

Which 3d printer do you use?

[@mattiasfagerlund]

I use two prusa printers, but I believe any would work.

[@turkey1099]

Did you use plaster of Paris?

[@mattiasfagerlund]

Yes. Though note that there are several versions of plaster of paris. Softer versions are appropriate for clay slip casting molds and less complex sculptures. For more comples sculptures - with finer details for instance - a harder version should be used. The harder version is sometimes called alpha plaster, sometimes dental plaster.

[@turkey1099]

@@mattiasfagerlund I'm a simple man. I'll probably just use plaster of Paris from the hardware store. I'm really surprised that the heat generated didn't seem to warp the PLA at all. And all of your stuff came out with such nice details. Thank you for this video!

[@TheDarknex]

where can I found those candles/house sculptures?

[@mattiasfagerlund]

I'm not sure what you mean, the 3d models for the molds or the actual sculptures?

[@TheDarknex]

@@mattiasfagerlund both! Or just the ones who are actually available

[@mattiasfagerlund]

@@TheDarknex Well, I haven't published any mold 3d models and I'm not currently selling any sculptures - they're all on a shelf in my home. Was there one in particular you were interested in?

[@TheDarknex]

@@mattiasfagerlund all of them to be honest ahahah I found them to be pretty interesting in style I was wondering if it' all your creation or if you got inspired by some other art/artist/creation! I just wanted to see and know more (: