The Bowl

Tools

· Thin sheet of ply wood

· Laser Pinter

· Ruler

· Felt marker or scraper

· Pencil

· Approximately 400 x 400mm piece of aluminium

· Guillotine

· Tin Snips

· Sand Bag

· Rubber mallet

· Metal hammer

· Dolly

Step 1, Laser Cutting:

The first step in making the bowl involved preparing 2 sets of guides, that would help you measure your bowl and mould it to the right shape.

· A set 3 rings (concentric rings)

· A female radius guide

With Martin’s help, we were able to use the laser printer to cut these guides out of thin sheets of plywood.

Step 2, Cut your rough, square piece of aluminium

Using a felt marker or scraper and a ruler, we then measured out a square of approximately 400 x 400, for our largest to comfortably fit into. Once our square was marked out, carefully use the guillotine to cut it from the longer length of aluminium.

Step 3, Mark out concentric rings

Using the marker or scraper used in step 2, and the concentric rings made in step 1, trace the outer edge of the circles onto your aluminium.

The outer edge of the outer ring represents the diameter at which you are required to cut your aluminium circle.

The two inner two rings serve as useful guides when using the English wheel. These will help you know and concentrate your work on the inner circles where more work will be required, and gradually less and less work as you work towards the outer ring.

Step 4, Cut out your aluminium circle

Using the tin snips, cut along the outer marked line, until you are left with a disc.

Step 5, English wheel or hammer?

Choose your plan of attack, English wheel or hammer. Both methods work by compressing and elongating the aluminium squeezed between the two surfaces, however the English wheel is theoretically a lot faster, as it can squeeze the aluminium in long strides at a time, as opposed to the hammer, which will only mould the aluminium in the area of impact, one hammer strike at a time.

I initially begun my work with the English wheel, but found that the two wheels on the press weren’t aligned, and despite my efforts, changing the wheels and fiddling around, the wheels continued to make an impression into the aluminium, leaving a line.

As a result I chose to give the hammer a go.

Step 6, Shaping through hammering – commencing

Grab the sand bag and place it below your aluminium plate. Aiming for the middle of the plate, use the obtuse end of the plastic hammer to make blunt, wide indentations into the aluminium.

As advised by class tutor, Daniel, it is better work slow and get things done right, then working hard and fast, and later having to try and undo any mistakes made. With this in mind, work slowly making particular effort to land each strike on the intended target.

Start shaping! Start with the obtuse end of the plastic mallet

Once the centre of your bowl starts to bow out, we will try and place this bow into the “side” of the sand bag, this will make hammering easier.

To do this dangle your sand bag in one hand to make all the sand fall into the lower edge. Placing the bag back onto the table, use your fist or the obtuse end of the plastic hammer to deliver a few strikes into the edge of the sand bag where the sand is accumulated. Your aim is to create somewhat of a concave shape in the bag, to receive the hammer blows and mould the aluminium as you go. This will also act as a “catch” to hold your bowl from moving around the sand bag too much.

Holding the plate with your left hand, and the hammer in your right, rotate the bowl after each hammer strike. As you rotate the bowl, your aiming to rotate evenly and steadily so as to keep each hammer strike at an equal distance to the last. This will help you keep track of what areas have been worked, and which areas haven’t. After completing one full rotation of the bowl, move your bowl further up or down the sand bag, and start the process again. Remember, a steady approach means that you are less likely to make an error, and any error should be easier to fix, if you aren’t attacking your bowl with over powering strikes.

Step 7, Measure your curves

Turn your bowl upside down, and, taking your female radius guide, check your progress. This guide measures the curve you have achieved in your bowl. 3 different radiuses have been provided on the one guide, so as to allow the craftsperson to select the radius most aligned to their bowl. This gives the craftsperson a greater range to work in, should they accidentally overwork the radius they were initially targeting.

Your aim here is to continue to work the bowl by repeating steps 6 & 7 until you find minimal to no gap between your selected radius and your bowl.

Step 8, Make a male radius guide (optional)

You may, as I did, find it a little tideous to have to constantly stop hammering, turn your bowl over, chech with the radius guide, turn the bowl over again and continue hammering…

If this is you, you may choose to make a male radius guide, that you can run across the inside of your bowl, thereby removing the need to flip over and flip back your bowl.

This is a simple enough process. Taking your selected radius on the female radius guide, place it over a scrap piece of aluminium and mark the curve onto your scrap piece of aluminium. Making sure you leave enough aluminium for you to hold and grip onto, proceed to cut along the marked line with a set of tin snips.

Cut as close to the line as possible with the tin snips

Using a file, file along the cut until you have an edge that closely aligns to your marked line.

Check your radius guide by placing it into the female guide. If you have no gaps and the curves align, you’re ready for measuring.

Check male guide

Now you can use this guide to help you check and maintain your desired radius without having to flip your bowl over.

The guide helps illustrate the areas still requiring work

Again, the aim here is to work the bowl until you have minimal to no gap between the bowl and the guide.

Nearing the right radious

Step 9, Marking (Optional)

Between stopping to check your radius and getting back to hammering, sometimes you can loose your bearing, and not remember exactly what area needs working.

To assist with this, take a pencil and mark the areas that require work as you measure – but don’t mark the whole bowl in one go; measure and mark a small area at a time, then work this area and return to measuring and marking.

'X' marks the spot

Step 10, Hammer finish

Once you are happy with the curve that your bowl has, it’s time to start applying the hammer finish. Taking the metal hammer and dolly, place your bowl over the dolly, mouth side down.

Metal Hammer & Dolly

Ensuring to start carefully, you aim is to land your hammer strikes as close to the last as possible so as to achieve a look where all hammer strikes overlap and no piece of aluminium is left unworked.