Casting Plaster Plaques

Casting plaster plaques out of plaster of paris is a cheap way to get things to look nice - almost like those expensive ceramic objects of art you may like to look at. This is easy enough for children to do on their own once they have been shown by an adult.

You will need to gather some basic supplies before you begin casting plaster plaques. You will likely have to buy some plaster of paris, unless you have some left over after some plaster repair work at your house. Since it is a white chalky dust or powder you don't want this near food or in anyone's mouth. You need newspaper or garbage bags to spread on your work area - as there will be spills.

You need molds! The easiest way to get them is to collect them after a meal from a fast food restaurant or food booth in a mall. The plastic molds that hold your sandwich, or salad, - or the oval ones that hold a baked potato, many of those containers have great potential. Check them over for embedded or embossed recycle designs, usually on the lower layer. If that's the case, it would spoil your plaque, so cut or tear that part away, and use the other half.

Ready? Let's start.

When you have spread newspaper or garbage bags on work area, and laid your washed molds ready, pour about half a cup of water. . . .

Now pour the water into the container you will use to mix your plaster. (Don't plan to use it for food again after this, so be sure to ask permission before you take anything from the family kitchen). It's the ratio that makes the difference, so I like to use a yogurt cup for all my measuring, but a styrofoam cup will do.

Gradually shake the powdered plaster into the water. The amount can vary a bit, but the ratio is usually 4 parts plaster to 1 part water. So a half cup of water will take 2 full cups of plaster. However, do this slowly as you keep stirring - because sometimes it takes less and if you have dumped in all the plaster at once, you will have hard lumps, and your plaque will be a disappointment.

Your goal is to get the plaster to be smooth and creamy like sour cream or yogurt. By the way, NO metal spoon; the metal will be damaged. Use a plastic spoon.

You should not add more water at this point, but you can carefully add more plaster of paris - if the mixture appears too runny. Stirring will often cause the plaster to thicken too, so pausing a minute or two may save you further plaster and stirring. Experience is the best guide. (I've learned a lot from my fist flops).

Now you get to pour the creamy, still flowing plaster into your waiting molds. Try to do this evenly, although you can pick up the corner of the mold and give it a light thump-thump on the table and it will cause the plaster of paris to flow to a nice smooth, level surface.

It is smart to have extra small molds on hand so you can use up the remaining plaster on something useful. Here I like to keep lids on hand as they will make some extra round plaques. Also, if you can get some candy molds (remember, they are wasted for future food use), pouring plaster into those small spaces will give you fridge magnets to paint later.

It can happen that the plaster is starting to harden or set before you have finished getting it into the mold. So this is a time to work a little more nimbly. Smooth down the lumps with the spoon. Pick up the mold and give it a tap-tap on the table.

Quickly, before the plaster gets too set, you need to make a loop with a twist-tie and twist to make a good, sturdy hanger then spread out the ends a bit. Now gently press the ends and the twisted joint into the wet plaster about where the hanger will need to be for the plaque to hang on the wall. Try to get the loop to be far enough down so it will not show above the plaque when it is hanging on the wall.

We wanted one to hang the long or portrait way, and the other to hang in the landscape view.

Here you see that we had some extra plaster left so we poured it into a plastic tub's lid to get an extra plaque made. Notice the groove or ditch around the edge? That will create a nice frame for our plaque!

If you have lined up a number of plaques, you may have to rinse out your mixing container, and make another batch of plaster. Then pour some more.

Pouring your plaster plaques will be a separate craft session from when you paint them. This is because the plaster plaques need a few days to dry out very thoroughly so there is no moisture in them. Painting on damp plaster only causes them to break.

This sunburst plaque has a sunny base coat of acrylic paint. You only need to wait a few minutes before you carry on with the words or pictures you want to paint onto your plaque.

There! Now this plaque has a simple design with a message. This is where the artist in you can shine.

And if you don't care for a design, just wait for it to dry and then paint over it and try something else.

This is one of the extra lid plaques turned into a nice name plaque for a girl who loves mauve and purple.

See how much art fun you can have when you have poured, or cast plaster plaques to paint? When you get some really nice ones made you can give them as gifts.

Where to Find Plaster of Paris

Some people wonder where to buy plaster of paris. You can buy it in small cartons at almost any craft supply store, but it will be less expensive if you go to a hardware or building supply store. And if you are going to be making lots and lots of plaster crafts, (as I did for VBS for three years), find a wholesale building supply store, and ask for a large sack of plaster of paris. When I did that, a 20 kg sack cost $11 whereas a craft store carton with only a fraction of the plaster cost anywhere from $5 to 10. It pays to do some comparison shopping in your area.