Tutorial - The bowl
The bowl is a fairly basic, uniform shape which requires a number of skills and techniques to be created efficiently. I have selected this task because these techniques provide a strong foundation for metal working, and at the end of the task you end up with something that is actually useful. As I have already made this piece, this tutorial will guide you through the process, with the aid of additional resources I have created. The end product should hopefully look something similar to below:
Step one:
- Before we begin we need to first identify the tools needed to create the bowl. I have included photos and labels of all the tools I used however others might be useful if these are not available at the time.
Tin snips Nylon point mallet and timber mould
Body mechanic hammer Nylon edge mallet
Round dolly male component U-dolly male component
English Wheel
Step two:
- Select your piece of sheet metal and decide on the size of the circle. Obviously the larger the circle the larger the bowl. Find the centre of the sheet by dissecting the metal with two opposing diagonal lines as shown in the photo. From here you can scribe the circumference ready for the next stage of the process.
Step Three:
- Once the circle is complete, using the tin snips, trim around the edges carefully so as not to ruin the perfect shape or remove too much material. Try to not waste material if possible. Then similar to the photo, draw an inner circle purely to act as a guide for yourself to know where to begin the forming.
- As this secondary example was created purely for this tutorial, I didn't trim the edges, a classic example of 'do what I say not what I do.' The arrows seen here are the direction which the mallet is to be struck.
Step Four:
- Set the metal up on the timber mould over the hollowed section. Using the nylon pointed mallet, strike the metal along the inner line. This needs to be forceful enough to create a ripple or wave rather than just an indentation. The smaller the inner circle the deeper the bowl will be. This process can be quite tricky and will take some getting used to. If the ripple effect is not quite forming or you make a mistake don't give up, the process is only just beginning and the imperfections will be fixed further down the track. Bare in mind that in the video I'm only using one hand as the other is recording, not ideal and two hands should be used for support and safety.
- That ripple effect is a permanent deformation and with that comes strength and rigidity, and the beginning stages of the bowl shape. Continue this method along the whole circumference of the inner circle. As you can see, the shape won't be perfect, but at this stage that's not important. As metal is deformed, the strength increases drastically, you will notice how rigid the bow is even at this early stage.
Step five:
- The ripples are now surrounding the edges but these need to be flattened and smoothed out. Transferring the piece to the sandbag, and at a slight angle, use the large round end of the nylon mallet and reasonable force to hammer out the waves. Continue this too around the whole circle till happy.
Step six:
- Once again using the large round end of the nylon hammer, hammer out the centre down into the sand bag or wooden mould. The sandbag provides more support and less risk however the wooden mould is faster, comes down to personal preference. I did a bit of both for mine, and you don't want to risk thinning of the metal too much that it splits. Case in point:
- Continue this process as seen in the video until you get the depth required.
- Working from the centre out, using the round end of the nylon hammer work the metal in concentric circles. Using the basis that the centre is the bottom point, try to get some uniformity in the metal, and as you work outwards the bowl recess will form deeper and deeper. I took my time during this stage to get an extremely smooth curve, and the more time you spend the better the result. If there are large deformations, you can use the cast metal dolly forms and the body mechanic hammer to get these out however be careful as the metal on metal can damage the surface. I didn't require this as I spent so much time with the nylon mallet and the sand bag.
Step seven:
- Now that 95% of the bowl shape has been formed, it's time to get the surface perfect. Using the English Wheel (when you find it available for use), make sure the bottom wheel selected (anvil wheel) is the round profile. These can easily be replaced simply by lifting them out. Using a back and forth motion, play around with the fit, a tighter fit will stretch the metal more and deform it easily. A medium pressure is sufficient if the surface is similar to mine in the image above. The English wheel does the same job as the body mechanic hammer however for larger areas and more efficiently. The pressure can be adjusted by spinning the bottom handle which raises and lowers the bottom wheel whilst the top wheels stays still.
- The more the bowl is rolled, the better the surface texture is, so this could take a while. I went in on a quite day and achieved the above finish after around half an hour. You will notice that a really glossy sheen is achieved and a uniform round shape. Make sure to not just roll in the one spot and working methodically, make your way around the whole bowl.
Step eight:
- The final step is of course the most simple, and that's finishing. Firstly, the edges of the bowl might still be slightly rough from trimming and therefore need to be filed and sanded down. There are large boards with sandpaper attached in the workshop which can be secured in the vice and used to twist and slide the bowl along to achieve a level edge. There is also brasso in the workshop which is to be applied with a cloth or rag and rubbed into the surface. This will leave a dark residue which then needs to be wiped off, leaving behind a gleaming surface for a very useful and quality bowl. Final photos of the finished product can be seen below.
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