Last week I mentioned briefly that putting the tanks back together, welding the steel, is a much more difficult job than cutting them in two (not to mention very highly skilled).

The process of maneuvering the two halves into position and the spot welding is slow, precise and painstaking. As you can perhaps make out from today’s video every small weld is made centimeter by centimeter, re-aligning the metal between each fusion – it really is very exacting work. Once the circle is complete the result is a line of hundreds of individual spot welds that form the new joint. The welds are then hammered flat, with two men working simultaneously, perfectly co-ordinated, one inside the tank and the other outside – it’s really fascinating to watch.

After the hammering comes the final clean up. This is a two part process. Firstly comes the grinding, when the small humps and bumps of the join are removed, leaving a comparatively smooth, flat surface. Finally comes the polishing, when the tank is left with nothing more than a ‘brushed metal’ effect is visible (masking tape is used the give this brushed effect perfectly straight edges). Et voila! Job done!

Of course, now that the new jacket is in place it simply needs to be connected and tested. The odd fact is that this work is not carried out by the same people that made the tank modifications. Connecting to the cold water system will be carried out by either a plumber or refrigeration engineer in the coming days.