The white plaster printing materials information page says that 3D-printed objects made of white plaster are "coated in elastomer which gives it added rigidity". What is this elastomer (does it have a trade name)? Can I use a penetrating epoxy as an infiltrant on an elastomer-coated part so that I can sand/polish it? I'd also like to be able to later flood it with resin, so as to give it compressive strength (it's hollow, to save on costs), so I can use it as part of a compression mold for composites.
This is my first time working with/ordering a 3D-printed part, so I'm not sure how strong it will be or what my finishing options are.