How can I waterproof a sculpture made out of plaster of paris?

Answer 1

Waterproofing will be difficult but it is possible to make the sculpture water resistant by spraying a clear coat of wax or latex over it

Answer 2

Plaster Of Paris Waterproof

Answer 3

Hey Lawrence,

Thinking literally out of the box, you could use water proof plaster. See first site.

Then, if you use the classic because it is cheap, what you want to do is prevent water from entering the poors of the plaster.

I think the best solution is step 8 of the third web site below. Here is the text:

"Waterproofing: Your plaster disk needs to be waterproofed. You should waterproof the back and sides. The front depends upon the use:

* If this disk is for a tile tool, put one coat of epoxy on the front of the tool (you will use a second coat to adhere the tiles)
* If this disk is for a pitch lap, the pitch will adhere best to the raw plaster, so only waterproof about ¼" of the front edge, but not the front itself.

We use epoxy glue to waterproof at Stellafane, it is rugged and durable, but that can be expensive in small quantities. Polyurethane finish is a less expensive alternative. In any case, plaster is very porous, and it may take several coats of whatever you choose to get a durable, waterproof finish. Since you will be dunking your tool in water buckets, do a very good job at waterproofing - Plaster will disintegrate if it gets wet!

Note that some people have found 5-minute epoxy setups up too fast to soak in well on a first coat, and may peel off under heavy use. Slow drying epoxy has plenty of time to soak into the plaster, and therefore usually takes two coats."

Answer 4

Give it a couple of coats of liquid acrylic varnish or gel. It will completely dry in a few days and be completely waterproof.