How to Cast a Resin Slot Car

Exact replicas of this body can be reproduced in resin.

Many exact resin replicas of a master slot car body can be made for very little cost as long as you start with a carefully prepared mold. An existing car body can be the master or an original master body can be carved out of wood, clay or plastic. Whichever is used, the master should be as flawless as possible since even tiny marks will be reproduced. The materials and equipment needed for resin casting are available from most hobby supply stores.

Things You'll Need

• Sandpaper
• Filler putty
• Plastic or styrene sheet
• Exact-o knife
• Super glue
• Modeling clay
• Paper cup
• Popsicle stick
• Silicon rubber mold material
• Rubber to rubber mold release
• Liquid resin mix

Instructions

Creating the Mold

1. Sand the master body carefully and fill any blemishes with modeling putty.

2. Cut pieces from plastic sheet for a box large enough to hold the car and the mold material. Cut an over-sized piece for the base.

3. Fill the inside of the master body completely with modeling clay. The clay should fit tightly to the edges of the windows and lower body. Carefully clean any clay from the outer surface of the master.

4. Make a bed of clay a little larger than the mold box and set the bottom of the clayed-up master firmly on the bed. The lower body edges must be completely exposed.

5. Set the clay bed onto the mold box base. Trim the bed to the size of the box and assemble the box sides around the bed. Glue their edges together.

6. Mix part of the silicon mold material in a paper cup. Carefully pour it into the mold box to cover the roof of the car plus enough for a sturdy mold. Allow the silicon to set overnight.

7. Flip the box over and remove the plastic base. Completely remove all of the clay from the lower half of the box.

8. Apply mold release to the underside of the upper mold half.

9. Mix the rest of the mold material and pour into the mold box. Allow the second mold to set overnight.

10. Disassemble the mold box, separate the mold halves and remove the master body.

Casting a Slot Car Body

1. Mix the resin material in a plastic cup, carefully following instructions. Slowly pour the resin into the upper mold half, filling the cavity.

2. Press the lower mold half into the cavity. Squeeze excess resin material out the sides and make sure no air is trapped. Allow the resin to fully set.

3. Separate the mold halves and remove and clean the newly cast body.

Tips & Warnings

• Cleanliness is important every step of the way when casting with resin. Any flaw or spec of dirt can be reproduced in a resin casting.

References

• Alumilite Corporation: Molding a Slot Car
• Alumilite Corporation: Casting a Slot Car

Resources

• Read this Article in Spanish