Introduction: @Techshop Menlo Park: Creating a Decal for a Multi-curved Surface With a Template

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Ever since I got my little British bike I've been wanting to put a Union Jack decal on the tank. My first attempt failed miserably because I didn't account for the curvature of the tank at all. My second attempt also failed miserably because I tried to do my measuring with the decal (not affixed) on the tank. This is the third attempt and I took a different tack. I first created a template of the parts of the tank that would allow the decal to lay flat. Here is how it went...

Step 1: Making a Template

I decided to use wax paper for the template. This was mostly due to the opacity of wax paper allowing me to see the tank while tracing the template. Also the wax paper would lay on the surface of the tank in much the same way as the decal. This way I could see the spots where the decal would get creases and avoid them. It was also very easy to cut the hole for the fuel cap.

I laid the wax paper over the tank and taped it down with some masking tape. First I marked out the hole for the fuel cap.

Next I placed on hand on the center of the tank and slid the other hand down the wax paper until I went passed my desired decal size or the wax paper started to bunch up.

Marking these spots allowed me a general idea of the limits for my decal. This allowed me to draw a smooth shape for the outline of the decal.

Step 2: Applying the Template to the Decal

I've already written an Instructable on making decals so I'll skip that part. This was a two-layer decal so it was a little more fun to make and align.

Since my Union Jack is 4 parts on a red background I was able to make it larger than if it were one solid piece. In making my template I tried to account for the spaces between the decal sections. This also meant that the sections didn't need to be exactly the same size since it wasn't symmetrical.

With this in mind I laid the template over the decal to observe how it was best suited to the tank and the cut. Once I decided on the decal layout I cut it out.

Applying it was the hard part. First I cleaned the tank. Then I peeled off one of the quarters and sprayed a liberal coat of Rapid Tack on the decal adhesive side. This made it much easier to apply to the tank and maneuver into the desired position. I did make a small mistake in trying to cover a chip in the paint. It upset the alignment of my decal. It didn't cause the decal to wrinkle or bunch though so I am happy with the result. I'll fix this in the next version.

Thanks for reading.