I have a fairly large sign 240x30 that I am splitting into three sections. During install can I butt the 3 pieces next to each other. An expansion joint will make the sign horrible. It is half inch thick. Any thoughts anyone?
"Field seams" are not difficult to create and work well if done right.
Glue a vertical strip of plastic to the backside of one of the faces, allowing half the srtip's width to extend beyond the edge of the face. The next face slides loose against the edge of the first face in front of the added strip so that the strip covers the seam from behind. If you are using white acrylic, use clear acrylic for the seam piece, the thinner the better. I like 1/16th or 1/8th for the plastic. The thicker the seam strip is, the more visible it will be. Add a strip of white translucent vinyl to the front of the seam strip, and even if the crack tries to open a little, the strip covers it to prevent a light leak.
You may need to cut the seam strip at its top and bottom to make sure it clears retainers. And if both, or all three faces are suspended from hanging bars, they will hang flat and usually stay together. On the other hand, if the faces rest on the bottom retainer for support, there is more chance for a light leak as the faces try to sag. Even large channel letters can be fabricated with seams this way.
One shop I worked at when I was younger had a standing rule that any face over eight feet in length was to have a vertical field seam—always. This allowed one worker to safely service the sign without help.
Brad in Kansas City
