PLA and Plaster of Paris

In summary: Gold or silver.In summary, 3D printing the negative halves of the item you want to mold and using a mold release compound will make it easier to take the print out of the plaster.
  • #1
TL;DR Summary
I need something that will dissolve PLA but won't affect plaster of paris.
I'm trying to make a mold because I want to add something to some jewelry. I 3D printed the symbol that I wanted, and tried to make a mold with Plaster of Paris. But I can't take the print out of the plaster, and I don't want to damage it with a knife. I'm thinking ethyl acetate? A quick google search says it melts PLA, but I don't know what it does to plaster. Anyone have any ideas?
 
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  • #2
Welcome to PF. :smile:

Could you try it again and use a mold release compound to make it easier to take apart?
 
  • #3
berkeman said:
Welcome to PF. :smile:

Could you try it again and use a mold release compound to make it easier to take apart?
i don't think i have access to that :(
 
  • #4
inspacewithcallisto said:
i don't think i have access to that :(
Why not? There are lots of mold release agents/compounds, including some that you can make for yourself. And Amazon has plenty of choices...

https://www.amazon.com/s?k=mold+rel...ture-scomp&tag=amz-mkt-fox-us-20&ref=aa_scomp

1665082127387.png
 
  • #5
inspacewithcallisto said:
tried to make a mold with Plaster of Paris
No idea what you plan to do, just in case: plaster of Paris won't survive high temperatures.
 
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  • #6
inspacewithcallisto said:
Summary: I need something that will dissolve PLA but won't affect plaster of paris.

I'm trying to make a mold because I want to add something to some jewelry. I 3D printed the symbol that I wanted, and tried to make a mold with Plaster of Paris.
Hey wait a minute... Can you just 3D print the negative halves of the item you want to mold? In essence, 3D print the 2 halves of the mold and use it (with mold release compound!) to mold whatever your symbol/thing is.

https://3d.formlabs.com/moldmaking-...XPwhF9gGK1-cQcgnhePLgeABHGjJkFowaAh3IEALw_wcB

1665096613245.png
 
  • #7
You can also print in PVA and use water to dissolve it.

BoB
 
  • #8
PLA is soluble in dioxane, acetonitrile, chloroform, methylene chloride, 1,1,2-trichloroethane and dichloroacetic acid.

Plaster of paris is not soluble in any of these with the exception of dichloroacetic acid. I would use methylene chloride.
 
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  • #9
I'm behing the curve here. What material is your final piece?
 
  • #10
It would either be gold or silver?
 

1. What is the difference between PLA and Plaster of Paris?

PLA (polylactic acid) is a biodegradable plastic derived from renewable resources such as corn starch or sugarcane. Plaster of Paris, on the other hand, is a white powder made from gypsum that hardens when mixed with water. PLA is commonly used in 3D printing, while Plaster of Paris is primarily used for creating casts and molds.

2. Can PLA and Plaster of Paris be used together?

Yes, PLA and Plaster of Paris can be used together in certain applications. For example, PLA can be used as a support material in 3D printing when creating molds made from Plaster of Paris. However, it is important to note that PLA may react with the water in Plaster of Paris, so it is best to use a barrier such as a release agent or coating to prevent any unwanted reactions.

3. Are PLA and Plaster of Paris safe to use?

Both PLA and Plaster of Paris are generally considered safe to use. PLA is biodegradable and non-toxic, making it a popular choice for environmentally-friendly products. Plaster of Paris is also non-toxic, but it can cause minor skin irritation if it comes into contact with the skin. It is important to follow proper safety precautions when working with Plaster of Paris, such as wearing gloves and a mask.

4. How long does it take for PLA and Plaster of Paris to dry or harden?

The drying or hardening time for PLA and Plaster of Paris can vary depending on factors such as temperature and humidity. PLA typically takes 24-48 hours to fully harden, while Plaster of Paris can take anywhere from 20 minutes to several hours to dry depending on the thickness of the plaster and the environment it is in.

5. Can PLA and Plaster of Paris be recycled?

Both PLA and Plaster of Paris can be recycled, but the process may differ for each material. PLA can be recycled by melting it down and using it to create new products, while Plaster of Paris can be recycled by breaking it down into a powder and using it as a soil amendment. It is important to check with your local recycling facilities for specific guidelines on recycling these materials.

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