Making a Sign Blank

A friend of mine paints and makes vinyl decals for signs. He had a project that required making a sign out of some form of polyurethane or foam board. The material was about 1-1/2" thick. He had drawn the outline of sign but didn't have the equipment to cut out the shape he wanted so he asked me to cut it out for him. My main concern was that I wanted to make sure the sign was perfectly uniform - a mirror image from side to side but I didn't really want to use a quarter sheet of plywood on making a single template. Instead I made two templates - one with half the top pattern on it and the other with the entire side.

I got a bit ahead of myself in that I cut the rough shape following the outline using my jigsaw before I created the templaes. When I laid out the templates on the outline I realized that the original outline sketch was not a perfect match side to side. It was close enough that in the end I managed to get the completed blank cut with mirror images side to side while staying within a 1/32" from his original sketch lines at the points where the lines came closest to the template. Lesson learned, always create the templates and validate the layout side to side before cutting. Using the templates I cleaned up the shape using a 2" edge trim bit in my router. The material cut very easily though it left a sand like residue on everything. I finished off the sign blank using a 1/4" round over bit to ease the edges. My friend requested this as apparently the paint won't stick as well to sharp edges.

The photos below shows the finished sign blank - I even splurged, I hired a super model to hold the sign while I took the picture. I don't think the super model was impressed with the gig though, but she at least smiled for the second photo. From start to finish it probably took about 3hrs. The bulk was in drawing the shapes onto the templates and then cutting and refining the templates so they had smooth curves. I'm pretty pleased with the way the sign blank came, it really looks good.