We started by drawing out a diagram for the aluminum frame of the pontoons, taking into account the size of the pontoons, the ease of manufacture, the practicality, and other external variables (expanding of pontoons, tightness of fit, etc.)
We then went downstairs to create a mockup of the frame using aluminium, in order to learn about the tools and think about a workflow for construction that would allow us to be efficient and practical.
We looked through many nearby shops that sold metal to source steel, however we only found one shop that sold steel - and at a high price tag ($150). We purchased 2.5 meters of the steel angle bar. The cheapest shop sold 2 metres worth of aluminum angle bars for $63.
To make the new steel truss, we used the same aluminium strips as in the previous prototype. It took roughly an hour and a half to finish a metre of the frame (3 people).
We also looked at steel beams to support the mouth of the oyster: steel seems to be the safest option as well.
It's important to note that we cannot afford mess-ups when using steel but we can easily replace aluminium bars at a low cost (even though we will try our best not to).
Points to note:
- Use a sharp pencil to draw the holes
- Use the pillar drill to make the holes (more accurate, easier to operate)
- Use the angle grinder to file down the edges
- We will be going with aluminium for the frame
- The riveting machine will be used to put in the rivets