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Tonkputer by Nev@Lehmä

Tonkputer by Nev@Lehmä Preparation M

Preparation M

Let's have a closer look at the milk churn.

Tonkputer by Nev@Lehmä Preparation M Tonkputer by Nev@Lehmä Preparation M
The surface was covered with scratches, many over 1mm deep but luckily there weren't any major dents. Even though I knew it was made of aluminium, it was still much lighter than I thought it would be when I picked it up. I decided to leave the handles in place but the chain connecting the churn and the cap would be removed.

What are my project plans then? Since aluminium is easy to polish compared with steel, I decided to polish the upper part and the base to mirror shine. I wanted a large, curved perspex window and an aluminium frame for it. Since the whole project has a cow theme I decided to cover the middle part of barrel with cow-like cloth. In the border of polished surface and the cloth there would be black aluminium mouldings mounted with shiny hex bolts. The same bolts would also be used mounting the window frame.

Let's get moo-ving

Tonkputer by Nev@Lehmä Preparation M Tonkputer by Nev@Lehmä Preparation M
The first step was to cut two holes in the main body: one for the window in the front, and a smaller slot in the back for the rear ATX motherboard connectors. Cutting straight lines on curved surfaces can be tricky, but use the old rule of measure twice; cut once, make sure your piece is held down with a vice, or an assistant, and use a steady hand.

In this instance, I used a combination of angle grinder, jigsaw, Dremel, and iron saw to make these cuts. I use a file to smooth the edges for a neater finish, and so I wouldn't cut myself.


Tonkputer by Nev@Lehmä Preparation M Tonkputer by Nev@Lehmä Preparation M
I think the task of sanding / polishing probably took the most time of all for this project. As I said before, the churn had over 1mm deep scratches that had to be sanded away. Though it is made from aluminium, the sanding wasn't easy at all. Unlike isolated blemishes, I couldn't just work on the small area around the scratch - I had to sand a large area around it to avoid making a dent.

I started with a 60-grit paper (only it took dozens of work hours) and continued with 80, 120, and 180 grits, finally working my way up to 240 and 360 grits; the lower the grit number, the coarser the sandpaper is, if you didn't know. The pictures here show the sanding at 80-grit level - compare it with the previous pair of photos (above right) and you will see how much work it was.