Plaster Models for School Project ("Plaster- Mache")

My step daughter needed help making models for a school project showing the evolutionary stages of a whale. I showered her a technique I call "Plaster- Mâché " It follows the same concept as papier-mâché, but uses Plaster of Paris which gives you much more versatility when sculpting the model. This instructable also includes creating display stands for these models.

Materials

- Newspaper

- Masking Tape

- Paper Towels

- Plaster of Paris

- Sandpaper (various grits)

- Assorted Paints

- Clear Coat

- Wood Trim (for stands)

- 1/4" Wood Dowels (for stands)

- Wood Stain (for stands)

- Wood Glue (for stands)

 

Tools

 

- Saw/Mitre box

- Drill w/ 1/4" bit

- Scissors (optional)

 

Most home improvement stores have a good variety of wood trim styles. We chose a nice chair rail design that was about 3" wide and 1/4" deep.    Cut the trim into the length you will need for your model. We used 14". Then cut the dowels to the height you want the model to stand. Keep in mind the dowel will go partially inside of the model.   Drill two 1/4" holes in each trim piece and then glue the dowels in place. We glued them from the bottom, so that no excess glue would show from the top. Once the glue dries stain the pieces and set aside.

Using the masking tape and newspaper, rough out the basic model shape. Try not to use too much masking tape as the plaster binds to the newspaper easier than tape. Don't worry about making the model "perfect" at this point, that will be done with the plaster.

Tear (or cut) the paper towels into 1" wide strips

Mix up a plaster into a "runny milkshake" consistency. It should be a little more runny than if you followed the package instructions. We don't want it hardening too quickly!

Saturate a strip of paper towel in the plaster mix, and then apply to the model as if you were putting a cast on it. Continue doing this until the entire model is covered.

When the plaster mix begins to thicken, start taking some and coat the model with it. Ideally none of the texture from the paper towel should be visible. You want the plaster to be thick enough that you can sand it without exposing the paper towel itself.

After this step you will need to let the models sit for a few days until they have FULLY dried. They will feel lighter and will not be cool/moist to the touch. If you are in a time crunch, you can let them spend a few hours in the oven at the very lowest setting (170F typically) to speed up the water evaporation.

Sand the imperfections out of the models. The more time you spend on this step the better your final product will be. If needed, you apply thickly mixed plaster to build up or patch areas on the model. When completed, wipe the models off with a damp paper towel. If there is plaster dust left on the model you'll have a hard time getting the paint to stick.

Paint the models as required. I would suggest using acrylic paint, but really anything will work. Once the paint dries be sure to finish with 1 or 2 clear coats. This step is very important to keep the paint from flaking off over time. After the clear coat dries you can finish any detailing to the models. We used heads off from sewing pins for the eyes. On one model we also used flocking and faux fur to give it the look/feel we needed. (Note: to apply flocking dilute some elmer's glue with water, paint it on, and then liberally cover with flocking )

Finally, CAREFULLY mark and drill 1/4" holes into the models matching the dowel spacing on the stands. Glue in the dowels and you are done!

If you've enjoyed this instructable please rate it!  Also, be sure to check out my other instructables!