Design.... this will be her project to learn these processes.
This was a two day workshop. Very labor intensive and challenging. To
learn process you need a good project and Shawn McCurdy had a few different
ideas that appealed to her. I always encourage each participant to draw
the designs with as much detail as possible. We decided on a great rendering
that she had for a birdbath. Something that I thought would be achievable
in a two day workshop.
first order of business was to cut the top basin and the base
out of 3/16" aluminum sheet using the plasma cutter. The
top basin is 22" square and the base is 18" square.
annealed the pieces with the OA torch, using the "paint
stick" method of determining heat, then cooled them with
the hose. While annealing, the pieces were suspended between
2 supports and they slumped or warped downward, which gave me
some shape for free!
Originally we had planned to use the treadle hammer to shape
the base and top. However, we quickly decided that a smooth
surface would look a lot better so I dished them entirely by
hand, using a wooden support and dead blow hammer. My arm is
supports were made from flat bar stock (1.5" by 1/4"
I think). I sketched out a representation of my design and we
measured the length of a representative leg, which turned out
to be about 4.5'. After cutting the bar to that length and shaping
each end to a point with the bandsaw, the first thing to do
was texture the whole piece using fullering dies in the power
hammer. It makes easy work of this!
the top end was bent into a support for the basin and the bottom
end into a support to attach to the base. Then the in between
part was bent and curved by stretching various sides on the
power hammer. (Did I say I liked the power hammer!) Repeat for
three more legs.
Assembly was the tough part. The supports all had to be the
same height. Tweaking the height was easy enough by putting
more or less bend into a piece, but that usually threw off the
position of the top or bottom horizontal end...eventually we
got it close and, starting from the bottom, welded it up. Wherever
legs touched they were tacked together to help stiffen the whole
Once we got all four legs put together with the base and basin,
we decided that it needed an extra piece, both to fill in some
of the negative space in the center plus to tie the legs together
in a few more places.
I made a spiral-y piece out of a short length of aluminum bar
that was left over, and we fitted it into the mid-section of
What's left to do? I need to go over the entire surface with
a scotchbrite pad and polish out some scratches. Then I'll clear
coat it, at least on the outside. I'm not sure how Permalac
reacts to immersion in water - anyone? I'm thinking now that
I'll leave the inside of the basin uncoated and just wax it
Here's Shawn McCurdy and her finished aluminum bird bath.
project would not only let Shawn anneal and dish some sheet
aluminum, to make the base and the bowl. But also, do some forging
of some aluminum bar stock, for the decorative vertical elements
that support the bowl. And once all the elements were made...It
left a challenging fabrication phase. Challenging because the
forged elements were very "free form and organic",
which really complicates the fabrication of a piece like this.
This was all part of the plan.