Trellis Craft
How to Make Your Own Copper Pipe Garden Ornaments
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The technique described below is an alternate way to measure the seven sections of the coiled copper tube for the "Spiral from Copper Tube" project on page 135 of the Trellis Craft Book.

The technique shown in the book is correct IF you can get SEVEN half-circles from the coil of tube.

If the 10 foot tube you buy is coiled differently, and you cannot get seven half-circles by the technique shown in the book, then you will need to measure each of the seven pieces instead.

You need to measure lengths along the curve of the tube. The easiest way I have found to do this is to use a piece of solder marked at the lengths given below. First straighten a piece of solder and mark it with the seven measurements. Then you can bend the solder along the centerline of the coiled tube, and transfer the measurements from the solder to the tube.

If you don't have solder, other alternatives are to use a piece of string in the same way, or mark the measurements on masking tape and apply the tape to the coiled tube, or use a cloth dressmaker's measuring tape.

Tube section number
Length of tube, measured along the curve
1

20 3/8"

2
19 1/4"
3
18"
4
16 7/8"
5
15 5/8"
6
14 1/2"
7
13 1/4"

Be careful when you buy coiled copper tube!

Usually coiled soft copper tube is described in the same way as straight hard copper pipe. In other words, what is called "1/2 inch" copper tube uses the same fittings as "1/2 inch" straight copper pipe.

But I have noticed one manufacturer's labels at one of the home centers that stresses the OUTSIDE DIAMETER of the tube for some reason. So they call the tube "5/8 inch O.D. copper coil" and then underneath that they say "1/2 inch nominal size". This is what I call 1/2 inch copper tube in the book. (Remember "nominal size" means what something is called. You want tube called "1/2 inch".)

If you were to mistakenly buy a coil of "1/2 inch O.D. copper coil" you would actually be getting 3/8 inch nominal size tube, and it would not match 1/2" fittings.

You want to buy 1/2 inch nominal size tube if you are using 1/2 inch fittings. Ignore the "outside diameter" or O.D. and look for the nominal size.