A Bubble Screen Exhibit      The way I built the ones I built:


You need a trough.

A small one could use the plastic or metal trays for paint rollers or for hanging wallpaper.

A wooden box lined with fiberglass can be long and straight, curved, or angled like a mirror in a clothing store.

I once cut a tractor tire in half zigzagging around the center of the tread between the lugs. (Dozens of saber-saw blades later . . . ) It is still in service after some 20 years. No fish-line required.


Place screw eyes in the trough to hold the bottoms of the fish-line. Put some epoxy or silicone sealant in the holes so you don’t create leaks. If the trough is light, you have to hold it down or the fish-lines will lift it. If it is on the floor, anticipate kids tripping over it.


You need a bar.

I like PVC pipe, an inch or so in diameter, with end caps to fit. If you make a three-sided screen, there are 135-degree elbows available. For a circular bubble, I bent ¾” gray electrical conduit using boiling water to soften it. (I made a long boiler with a piece of galvanized pipe and a hot water heating element.) PVC pipe is light enough that it will not seriously injure a child if it drops on him.


Drill small but not snug holes through the ends of the pipe at the distance of your fish-lines.  To make it ride straight on the fish-lines, you can either triangulate the lifting rope or put a Tee and an extension in the center. Curved or angled bars will need three or more points of support.


You need fish-line.

Use heavy weed-eater cord. Fisherman’s knots hold well, but put a bumper (rubber hose or similar) over the knot or the bar will wear it out quickly. The bar will ride up and down the fish-lines, which form the edges of the bubble. Keep the line handy for repairs. You do not need fish-line for a circular bubble ring.


You need a support.

This will hold the tops of the lines and a pulley for the lifting rope. Anticipate that sometime soon, a heavyset twelve year old will attempt to shinny up the rope. Attach it to the ceiling, to a tripod, to a support from the floor, but attach it well. Screw eyes again will hold the fish lines (Thread them through the bar first).


You need a pull rope.

I like nylon. It is soft and flexible and can be thrown in the washing machine when it turns gray. 3/8 inch or so is nice; sear the ends over a flame. Tie knots in the pull side for soapy handholds and to keep it from running the wrong way through the pulley.            Gordon McDonough


Bubble screen sketches