20/06/2012

Tinning

Okay, as you may know, copper is not suitable to be used with foodstuffs unless lined, usually with stainless steel (industrial process) or tinned (by hand, or hot dip-tinned industrially). I contacted few manufacturers, but, because these companies concentrate on big orders, I was not able to get it done, well I would have to wait for three months... So for the assessment, I wanted to give a hand tinning a try. I didn't know what to expect...


Here I got standard plumbers flux, tin, leather cloth and a test piece.
The flux is brushed on to the metal - tin melted and carefully pored on to heated surface. It was a bit hard to do it by myself, as I had to keep the torch in one hand, the ladle with the tin in other, and somehow use the cloth too. Also, I realised that I had to somehow rotate the metal, to try to get the tin to spread on to the surface. 

Well, it wasn't as easy as I thought. The test piece surface is convex, which obviously makes it harder to handle. But still, the tin just stayed in a liquid lump, like mercury, and just dropped from the surface on to the brick and set. No signs of trying to take its place on surface. 

This test piece was little more realistic. Again, poured the molten metal in and tried to move the tin around and then wipe the excess off. NO, it just didn't want to do it. Stayed in a molten lump and then just set. It seemed that the flux just kept evaporating too fast, which meant that the tin wasn't able to run well. 
Michael Rowe - Conditions for Ornament no 30

I was feeling frustrated after the failed attempt to do tinning. I contacted Michael Rowe, the  Senior tutor of Metalwork programme in RCA. Some of his work is tin-lined. Mr. Rowe was very kind and emailed me back explaining how I could get better results. He told me about this particular tin, that I should use. I am not sure if it is a secret, so I won't tell what it is, but I can say that it works!! 

tinning samples. Look at the amazing bubbly surface!! It looks like the surface is sweating.

Already much better result!

And here, I have tried on another test piece, this time, inside the vessel, the kind of surface that I would need to do the tinning. I ended up with burns and not still very satisfactory surface... I would need more and more practice in order to master tinning.

I decided not to tin the double walled surface myself. Too big risk of ruining the whole piece. Back to square one. Time to contact hot-dip tinning manufacturers.  

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