Tuesday, January 31, 2017

SBC 9 - A New Challenge

This is the post that I should have made yesterday and was too wiped to get it done. Read on and you'll see why.

Day 1

I'm picking up another gauntlet. Wendy Edsall-Kerwin has offered a challenge for several years - make a bowl (or complete it) on Super Bowl Sunday. I wanted to do this last year but we were in the middle of moving house. But this year I can say "challenge accepted!"

On Sunday I sketched out an idea for a bowl and tried to figure out how long it would take to complete. My guess was one day to raise it from sheet, another day to chase in the flutes. A day to etch a design into the vertical part of the bowl. Another day to solder on a rim, polish, and apply a patina. Apply the gold size to the interior the same day and then a few hours the next morning to apply gold leaf. All told, a little more than 4 days. That gives me some wiggle room since Officer Murphy is always on duty and he is The Law.
The original sketch. Measurements are wrong.

The border design.
There was one potential pitfall. I didn't have any half-round copper wire in a large gauge (6 or 10) so I'd have to order some or figure out something else to do. As it turned out, I ended up ordering some.

I got started about 11:30 am by annealing a 6 inch diameter disk of 16 gauge copper that I already had on hand. That was the first goof. I normally use 18 gauge, a little lighter. 16 gauge is just enough heavier that I had to work harder than I wanted to get the metal to move.

The first step is to lay out concentric circles as guides for hammering. The circles go on what will be the outside of the vessel. But the first pass for forming is to dish the bowl a little, working with a plastic auto body mallet and a hollow cut into a tree stump. Dishing works from the inside of the piece.
Hammer guides scribed in.
Dishing stump and mallet.
After that I started raising. I didn't bother to anneal between dishing and the first round of raising. I hadn't moved the metal that much, the guidelines were still clear, and I thought I could get away with it. It went well and I bouged the shape into some semblance of regularity with a leather mallet and a large (5" ball) steel sphere stake, then took it to the hot bench to anneal and pickle it.
Ready to raise.

After round 1.
From then on it was round after round of raising, bouging, annealing and pickling. I tried to take photos at each round but apparently missed some. After round 2 I spent some time setting the foot and beginning to define it. I refined it a little over the next several rounds and was then able to leave it alone. As the bowl rose, I took note of where the profile was supposed to transition from hemisphere to vertical. When I got close to that point I started to planish the hemisphere part so that I could get it nice and round and smooth. I used a smaller (3" ball) steel sphere stake for that.
After round 2.

Round 6

Round 7

Round 8

Round 9
By 7 o'clock I had raised the bowl through nine rounds and was exhausted and hungry. It was obvious that I was not going to get the raising done in one day. Rather than push myself when I was too tired and risk making a mistake, I called it a day.

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