1. Choose a stable and lightweight board such as ¼ inch foam board. A large board will produce a more easily seen rainbow. Ours is 30" wide by 36" high.
2. Mask off a 2-inch border to keep a free area for handling; then spray paint the board with flat black paint. Allow the paint to dry thoroughly.
3. Using a spray adhesive with a broad and uniform spray (we used 3M Photo Mount Adhesive) lightly spray a uniform coat across the entire board. Apply a second coat at 90 degrees to the first coat. Make sure the adhesive does not have time to dry before applying the glass beads!
4. Let the board dry for 2 minutes and quickly broadcast the glass beads uniformly over the entire board. Then add additional beads to a depth of ½ inch or more.
5. Let the board dry for 24 hours, then remove the excess beads. Tapping the board lightly should get rid of most of the excess.
CAUTION - the beaded surface is quite fragile. Avoid touching the beads if at all possible.
Our glass beads are Ballotini Impact Beads, stock size AD (0.0041 - 0.0083 inches diameter.) They were purchased from:
MS Abrasive Equipment, Inc.
3910 Prospect Ave, Unit L
Yorba Linda, CA 92886
714.528.8893
www.msabrasive.com
Jack Horne, July 2003