You can create the arch as a backdrop piece for photo ops, or as something your guests will walk through. If you plan for people to walk through the arch, consider the height of your guests. If you don’t know the height of your guests, 6–7 feet (180–210 cm) is a good size. You may want to look for an area that offers some support for the arch, such as an existing doorway. The arch should be self-standing, but any additional support can be helpful.
To determine the size of your arch, you will need a long piece of rope or twine, a tape measure, a marker, and a rock. You may also need the help of a friend and a ladder or step-stool.
The most common size of beach ball is 11. 2 inches (28 cm), but they are also available in 16 inches (41 cm), 24 inches (61 cm), and other sizes. Inner tubes are available in a wide variety of sizes and thicknesses. You may need to purchase a few inner tube options and then measure them blown up. (The measurements on the package generally refer to the diameter of the inner tube, whereas you need to know the thickness. )
So 20 feet (6. 1 m) is 240 inches (610 cm). This is the total size of your arch. Your bases subtract 20 inches (51 cm), which leaves 220 inches (560 cm). The center beach ball (the one that makes the total number odd) subtracts 16 inches (41 cm), which leaves 204 inches (520 cm). Each beach ball-inner tube pair equals 22 inches (56 cm), and 204 inches (520 cm) divided by 22 inches (56 cm) equals 9. 27, which we can round up to 10. (If you round down, you won’t have an even number. ) For a 20 foot (6. 1 m) arch with these beach balls and inner tubes, you will need about 11 balls, 10 small inner tubes, and 2 larger inner tubes.
Arch 2 larger inner tubes An even number of smaller inner tubes An odd number of beach balls Latex glue (available at craft stores or online) An air pump to blow up balls and inner tubes
Remember, the order goes: a large inner tube at the base (on each side), followed by pairs of beach balls and small inter tubes.
Apply a thin layer of latex glue to the bottom base inner tube, and press 1 of your beach balls against it. Apply pressure for 20-30 seconds. Apply a thin layer of latex glue to the beach ball, and press 1 of your small inner tubes against it. Again, apply pressure for 20-30 seconds. Alternate between sides: do a few layers on the left, then a few layers on the right. Be sure to gentle curve the balls and inner tubes in the shape of an arch. Have your friends hold the arch in place as you connect the 2 sides. The top/center of the arch will need the most support. Be sure to glue the balls/tubes with the inflation tabs sticking out. This will allow you to add air as needed, and help with take down.
This step is optional, but advisable, especially if your arch will be outdoors.
Next time you use the arch, you may need to use latex glue to re-secure any connection that may have come loose.
