I wanted the five branches of the tree to be sturdy, but also as light as possible. I used 1" PVC pipes as a "bone" for each branch. They needed to be bent into the right shape.
First, I traced the previously made foam core branch pattern/mock up onto a wood board.
Starting at the thinnest part of the branch outline, I placed one end of PVC pipe between two large nails. I softened the PVC with a heat gun and began to bend it, conforming to the curve. I added nails where needed, cradling the pipe in place as I went along heating and bending. Once done, I had a completed jig to make the other four branch "bones" on.
I trimmed the tip of each pipe to size but left an extra 12" length at the base and bent it at a right angle. That portion was used to attach the branches on the trunk by screwing into the furring strip ribs.
Once all the bone pipes were on, I began to build them up. Since each branch had to match keeping to the measurements Vickie was knitting by, I used five Styrofoam balls per pipe as a "template of circumference" (for lack of better words to describe). Each ball was an increment of width in the design plan (5", 4", etc.). I skewered the largest first, ending with the smallest. Each were glued at the appropriate points. Now I had to fill in the gaps.
As I said, I wanted each branch to be a light as possible, so I bridged the spaces between the balls (and helped build up) with cut pieces of pipe insulating foam tubes.
Then I used expanding foam to fill gaps and rough in a more natural shape to the tree. It also created a light weight, but stronger support were the PVC pipe bones were just screwed in. At the base, the foam instantly hid the shelf brackets used to attach the trunk there. I was not concerned about how it looked right now. Building up the empty spaces and fusing parts together was the most important thing at this point. I let it expand away, drips and all.
Once dry, the foam was easily carved into truer branch shapes.
I left about a 1/2" of exposed PVC on the ends. There I added a 4-way pipe joint and curved pieces of pipe as extending branches. Next I started to base coat the tree in paper mache. I used sheets of heavy duty paper "shop" towels dipped in a thin mix of Fix-It-All.
I stopped at this point before I went any further and e-mailed pictures to Vickie so she could get a sense of what the finished tree will look like. It was a very good thing that I did. We discovered there was some miscommunication.
Next in Part Four... remember that Stonehenge scene from the movie Spinal Tap? Kind of like that in reverse.