Creating a rigid plaster cast of a horses back is inexpensive, and the resulting model minimizes the guesswork when shopping for a properly fitting saddle.

This procedure uses old-fashioned plaster casting tape and plaster of Paris for reinforcement. The tape is unrolled over the horses back, from one side, over the spine and down the other side starting at the front of the horse and moving towards the loin, moving the roll 2 inches each time so that there is a generous overlap.

REQUIREMENTS

• 3 or 4 rolls of Specialist 4 or 6 inch wide Fast Setting Plaster Bandage (not asbestos)
• Small bucket of warm water
• Sponge
• Felt tipped marker
• Carpenters level
• Level working area
• 2 or 3 people and 1 horse

PREPARATION

I suggest practicing the casting technique with a leg wrap before using the casting tape because the plaster sets quickly.

Two people can make a cast is the horse is well mannered, but it's helpful to have a third person hold the horse and the bucket of water to make it easy for the casters to wet their hands.

Sketch the cast on the horses back using a felt tip marker, then place a saddle on the horses back to ensure that the cast is the correct size.

The ideal cast covers the area that supports a saddle tree.

If you make the cast too large, you'll need more plaster tape to ensure that it will be strong enough to support a saddles weight. A cast that is too small won't capture enough of the back and shoulder to ensure a good saddle fit.

PROCESS

Choose a location with a flat, level surface where the horse can stand square.

The front feet must be aligned for the cast to capture the shoulder shape accurately.

Open the packages of casting tape, leaving the rolls in the foil until needed.

Fill the small bucket with tepid/slightly warm water. The water should be tepid; the warmer the water, the faster the plaster will set.

Wet the horses back, making sure the hair is thoroughly soaked; the cast will stick to dry hair! Keep your hands damp while working with the casting tape.

Place a roll of tape in the bucket, let water soak through the roll, raise it out of the bucket and squeeze out excess water

The first person unrolls 12 inches of tape from the base of the shoulder to the withers, defining the front edge of the cast on their side, then hands the roll to the second person on the opposite side.

Each new layer of tape overlaps the previous layer by at least 2/3 of the width of the roll.

The second person unrolls the tape on their side, going down the shoulder, then back up and over the withers to the first person.

Smooth the tape down with damp hands to remove wrinkles after passing the roll to the other person. Continue each new roll where the old one ended.

Make the back edge at the loin 3 layers thick, then continue the process moving towards the withers to reinforce the cast. Continue until all the tape is used. Smooth the whole cast lightly with damp hands, removing obvious wrinkles.

Once the cast is very firm but not dry, carefully lift it & pop it off the horses back. Don't bend it or remove it completely. It should rest on the horses back until rigid, but needs to be loosened from the hair as it becomes firm. If the cast dries completely without being lifted, it will stick to the horses hair; if it's pulled up too soon or removed completely it'll distort. I tap the cast to see if it sounds solid and test the edge until it feels firm.

Once rigid, it should be carefully set aside for 15 -30 minutes to dry completely.

FINISHING

Place the cast back on the horse and check the fit. Mark the mid-line (at the spine) of the back with a felt marker, and sketch where the girth sits on your horse to ensure that the saddles rigging fits the horse.

Casts can be reinforced from underneath with plaster of Paris for a sturdier model for fitting Western saddles

Use

When using the cast at a tack store to shop for saddles, place it on a saddle tree and level it with pads before placing saddles on it. The cast can be placed in an upside down saddle, but fit should be verified on a tree to ensure that the saddle can sit level on a horse.

Thanks to Steve Ray Gonzales of SR Saddles for sharing this process!