Making a H-D Fuel Tank Pattern

Snap Fab Tech

So you've decided to fabricate your own Harley-Davidson custom gas tank for a motorcycle project. Excellent! However, going about that job is easier said than done if you want the tank to look right (if you want to to look ugly and out of proportion, that's easier).

Enter the paper pattern. Drawing one of these out before you start cutting and shaping sheet metal will give you the blueprint you need to fabricate the gas tank you want. Today we're going to talk about how to create a paper pattern for duplicating an existing Harley-Davidson gas tank. Here's the step-by-step process to get you started on the road to your very own custom fabricated tank!

steps 1 & 2

Step 1 & Step 2

Big Joe

Step 1: This month we’re going to look at the basics of pattern making to replicate a traditional Harley-Davidson fuel tank.

Step 2: Go to your local print shop or newspaper printer and ask for a newsprint end roll; they’re cheap.

Step 3 & 4

Steps 3 & 4

Big Joe

Step 3: Some other materials used in pattern making are painter’s tape, fine-line tape, magnets, and a pencil or permanent marker.

Step 4:  Using the fine-line tape, the first step is to break up the tank into manageable parts to shape.

Step 5

Step 5

Big Joe

Step 5:  The number of pieces needed to construct this fuel tank will be determined by your level of experience in metal shaping and tools you have available to you.

Steps 6 & 7

Steps 6 & 7

Big Joe

Step 6:  Using the sections we created with fine-line tape, we start the pattern-making process.

Step 7: Cut a piece of the pattern paper large enough to pattern a section. With magnets, start smoothing the pattern paper on the flatter profiles of the tank.

Step 8

Step 8

Step 8: Where the fuel tank has a tighter radius or curve, you will tuck/fold/pleat the paper to help it lay over the curves holding the pattern down with magnets.

Big Joe

Steps 9 & 10

Steps 9 & 10

Big Joe

Step 9:  With the pattern paper now shaped, you can feel where the fine-line tape resides underneath and trace it with a pencil.

Step 10: Also trace both sides of each fold in the pattern paper.

Steps 11 & 12

Steps 11 & 12

Big Joe

Step 11: Now remove the pattern from the tank and flatten it back out.

Step 12:  For better visibility, all of the pencil lines are traced in black marker.

Steps 13 & 14

Steps 13 & 14

Big Jow

Step 13:  Being able to read a pattern is as important as making accurate patterns. When looking at the folds, we can see by the width of the folds that more “shrink” is needed at the widest part of the fold and less at the narrowest part of the fold.

Step 14:  The length of the folds show us how deep the shrinking needs to go into the pattern.

Steps 15 & 16

Steps 15 & 16

Big Joe

Step 15:  When the folds are farther apart, this section of the pattern will require less shrinking than the section where the folds are close together.

Step 16: If we look at the center of the pattern we’ll see this is the section of the pattern that will require stretching.

Step 17

Step 17

Big Joe

Step 17: The perimeter of the pattern with all the shrinking is where the metal will wrap around the radius of the fuel tank. Boom! That’s the basics of making a paper pattern.