If you have a pile of cracked plastic wiffle balls rolling around the garage like I did, this is one of those oddly satisfying little projects that turns them into something genuinely useful. In this tutorial, I’m turning melted-down wiffle ball plastic plus two simple pantry staples into sturdy, shatter-resistant drain grates that work well for light-duty outdoor drains, potting bench runoff trays, and garden splash areas.
I love projects like this because they use up something that would usually get tossed, and they’re quick enough to squeeze in on a Saturday afternoon between errands and meal prep. This one is best for confident DIYers who are comfortable working carefully with heat and making simple molds, and it’s especially handy if you need a custom grate size that’s hard to find in stores.
Materials
6 cracked plastic wiffle balls, standard 2.75-inch size
Instructions
1. Wash the cracked wiffle balls with warm soapy water, rinse them well, and let them dry completely so no dirt or moisture gets trapped in the melted plastic.
2. Cut the wiffle balls into small pieces about 1/2 to 1 inch wide; smaller pieces melt more evenly and are much easier to pack into the mold.
3. Stir the baking soda and cornstarch together in the metal bowl until evenly combined; this dry mix helps reduce sticking and gives you a simple packing medium while shaping.
4. Lightly grease the inside of the ring molds with a thin film of neutral cooking oil, then set them on a parchment-lined, heat-safe flat surface.
5. Toss the plastic pieces with 2 tablespoons of the baking soda and cornstarch mixture so they’re lightly coated, then pack them loosely into each ring mold.
6. Heat the packed plastic carefully until it softens and begins to fuse, then press it down with the rolling pin or glass jar while wearing heat-resistant gloves to flatten it into a grate blank about 1/4 inch thick.
7. Sprinkle a little more of the dry pantry mixture over the top if the surface feels sticky, then use the end of a spoon handle or a narrow dowel to open or reform drainage holes while the plastic is still soft.
8. Let the pieces cool fully in the molds until firm, then remove them and trim any rough edges with the shears for a neat fit.
9. Test each grate over your drain opening and sand or trim the perimeter slightly if needed so it sits flat without rocking.
10. Set the finished grate in place and check water flow with a quick rinse to make sure the openings are large enough to drain well while still catching debris.
Variations & Tips
Size adjustment: Use different ring mold diameters to match the drain you’re covering. I always measure the opening first and make the grate about 1/4 inch wider so it sits securely.
Hole pattern: For faster drainage, make fewer larger openings; for catching leaves and bigger debris, create more small holes. I like testing with a cup of water before calling it done.
Color mixing: If your wiffle balls are different colors, you can mix them for a speckled look. White balls usually give the cleanest, most uniform finished grate.
Best use: These work best in light-duty household or garden situations rather than high-load areas. I’d use them for utility and convenience, not anywhere that needs code-rated hardware.
Smoother finish: If the edges look rough after cooling, warm them slightly and press with parchment paper for a cleaner surface. It’s a small extra step, but it makes the finished piece look much more polished.
Make extras: Since you’re already setting everything up, make two or three at once for planters, tray drains, or backup replacements. That’s usually my approach with small projects like this—I’d rather batch it once than dig everything back out later.