To create mold for concrete using PLA

[Fazil Marakkat 0]

Hello everyone,

 

   i am interested in making concrete cast using PLA mold/template, but I have concern with the cast removal, do you know any lubricants to be used? What would be other challenges in doing so? 

[fergazz 60]

I believe that this video can help you: 

 

[fergazz 60]

5 hours ago, Fazil Marakkat said:

but I have concern with the cast removal, do you know any lubricants to be used?

you should find a release agent to separate the concrete to the mold...

[geert_2 557]

You need to make sure you have no undercuts, and that all side walls have draft (=wider opening at the top). Otherwise the models get stuck.

 

If in doubt, make the walls out of multiple parts, and provide strong flanges with holes to screw them together.

 

Provide big openings for pouring in the liquid, and openings for venting air. Make sure no air can get trapped.

 

Weight could also be a problem in big models: make the walls thick enough, and provide extra supports where required (like the beams on the sides of castles and cathedrals).

 

And heat development: I don't know how hot concrete gets, but gypsum gets warm and could melt PLA moulds.

 

For release agents, you will have to google. Not only do you need to find one that works well in combination with concrete, but it also should not inhibit the curing. Try on small test pieces first. Silicon oil might work.