Introduction: Weatherproof Padlock

I live in Alaska. I keep a padlock on the gate to my backyard to prevent someone from accidentally letting my dog out. I have discovered that if I leave the lock uncovered, soon I can't get it open to take the trash around. The recent Instructable on alternate uses for tennis balls inspired me.

Note and Disclaimer: Working with sharp objects (scissors and box cutters) and heat can be dangerous. Exercise caution when using the box cutter on the tennis ball. Always cut AWAY from your body and hands. Melted nylon burns like the dickens. Take every precaution to ensure that you do not touch any melted nylon or allow it to drip on your skin. It burns and sticks. All of this is the voice of experience talking. Adult supervision is a must. I probably should have had some......

Step 1: Materials and Tools

This is not a complicated project, so the list of materials and tools is relatively small.

Tennis Ball x 1

Type III Nylon (Paracord) 4 or 5 Feet



Box Cutter


Lighter (Not Pictured)

Step 2: Preparing the Tennis Ball and Cord

Mark the tennis ball with a straight line from on side to the opposite side. Use the box cutter to slice the tennis ball so it makes an opening when the sides are squeezed. Use the box cutter to start a small hole in the center of the side of the ball opposite the opening. Use the punch to push the end of the Type III Nylon through the ball and out through the slit opening. Tie an overhand knot to prevent the cord from slipping out of the tennis ball.

Step 3: Optional Key Lanyard

The lock on my gate is not so much about security as it is about preventing the inadvertent release of my dog. I have to take the trash/recycling cans through this gate weekly. I'm always having to go back in to get the key. I decided to leave a length of cord beyond the knot to act as a lanyard for the key. I slid the key on, tied a double overhand knot to secure the key. I even used the lighter to "burn" the knot. Be careful to heat the nylon just enough to make it bind, not melt. I plan on tucking the key up inside the tennis ball before placing the body of the lock inside.

Step 4: Installation

Find a convenient place to loop the cord so that the tennis ball hangs slit down. If the slit is facing up, like just placing a tennis ball on the lock hanging there, then the snow and water will fall in and freeze your lock. The captive water in the tennis ball would only make the problem worse. Place the lock into the tennis ball to adjust the length of the cord. Tie a loop in the cord next to the tennis ball. Then loop the cord around the convenient point and tie to secure. I used three alternating half hitches with a locking knot in the running end. I burned knot to prevent unraveling.

If you live in a place that freezes, I hope you can find this useful. Thanks for this opportunity to share.