Bowling Ball Fountain

Step 5 Joining the Balls

I originally intended to connect the balls with metal rods and epoxy. However, I decided not to bother with epoxy. I'll explain why a little bit later.

To join the balls we need to determine how long we want our rods to be. I chose a rod length of 6 inches, which means 3 inches of each rod will be in each ball. I have no logical basis for this length choice. It was arbitrary and based on my gut instinct that this would provide enough strength to hold the balls together.

Once I chose my length I marked it on the rods and clamped the individual rods into my bench vise. I then used my reciprocating saw with a metal cutting blade to cut the rods into 6 inch pieces. I didn't much care about the finish of the rods as they are going to be buried in a bowling ball. If you do care, or just don't enjoy your saw jumping like mad, use a hack saw to cut a starter notch in the rod. This will leave you with a cleaner cut and the saw won't jump as much. Repeat this process until you have the number of rods you need.

WIth your rods done it is now time to drill holes to receive them. First determine the diameter of your rods and then get drill bits of corresponding size. Next mark the placement of your rods around the central tubing hole. Drill out these holes to the proper depth with the appropriately sized bit. WIth that done do a test fitting. If the rod doesn't do in as deeply as it should there may be dust jamming up the works. Working the rod back and forth will help get the dust out, or you can tip the ball over and try and knock the dust loose.

Now we need to drill corresponding holes in the next ball. I tried several different ways and none was as accurate as I'd like. The fastest way was to use the holes I drill in the first ball as a template for the second. I set the butt of the marker in the hole and brought the other ball close up in the orientation I wanted it in. Then I would drill the hole in the new ball and place the rod. This let me keep it a little more stable as I marked the next two holes.

To do the holes for the middle (grey) and top (black) ball I tried using a template. I drilled the holes in other side of the middle ball, making sure they were offset from the holes in the other side used to join the middle ball to the bottom ball. This way the holes won't intersect and weaken the linkage.

I then created a rough paper triangle template to transfer the hole positions onto the the other ball. Just remember to flip the template over. The holes will be mirrored to each other when the balls are sitting side by side. Then mark the positions and drill the holes.

Once all the holes were drilled in the first two balls I brought them together. I first fed the water tubing through the central hole. This kept the balls in a good position while I put the rods in the holes. It should be a tight fit. I used a flashlight and a pair of pliers to guide/pull the tubing through the hole. Next I made sure the rods were in the proper holes and pushed the balls together as far as they would go. Then I used a 5 pound hand sledge hammer to "persuade" them to close the gap.

Now if my drilling had been really precise they would have slipped together with little to no trouble. However, since my accuracy was lacking I ended up having to use the 5 pound sledge hammer to persuade them. This is the reason I didn't use epoxy. I figured if I had to beat them into close proximity they were unlikely to work loose. Repeat this procedure to attach the last ball.