Squeaking clean! OK, now we start opening the roughing valve. You will see when the pump starts kicking into action as we evacuate the air from the vessel. It takes about 20 minutes to open the valve fully. We have two pumps. The roughing pump is at the back there. This is the line evacuating the tank and the diffusion-pump will come in later to get good vacuum. Right, 40 minutes later, and let’s see what the pressure is. Right, 10-to-the-minus-one [Torr]. That’s actually where we can start diff-pumping. Now we close the roughing valve and open the backing valve. You can hear a slight change [in the sound from the backing pump] as we are now evacuating the diff-pump itself. But there is still a valve in here that prevents … it from working this way. OK, so now we have evacuated the diff-pump enough. and we can now open the butterfly valve. Now we are roughing through the diff-pump but we haven’t started the diff-pump yet – that’s the next step. What we do now is open the water flow. We run the water through all these cooling pipes. There’s a heater down below that heats some oil The oil boils and the vapours of the oil reaches the speed of sound in a funny funnel system and that gets directed down onto the sides of the pump which is now water-cooled. The oil re-condense and taking molecules with it. This is the way the pump works [without any moving parts] Right, 15 minutes later and now you can see the diff-pump really kicking in, moving to 10-to-the-minus-two So if we switch to the other … range you can see the vacuum drop quite dramatically now. You can actually see it moving! [speeded up] We can now also switch on this gauge and it should start to register soon as the vacuum reaches 10-to-the-minus-2 it should start to come up on this gauge [speeded up] OK, its about two hours later and the vacuum has moved … from there … to there, one decade. Tomorrow morning we’d hopefully be ending up there somewhere. OK, another 4 hours later about and you can see it moved to nearly 2-to-the-minus-5. Right, overnight … next morning now. and you can see way down! exactly were we wanted it, so we can now go over to aluminising. So we start by dialling up 8 Amps and as the coils warm up, you can see the current fall. and as the coils warm up, you can see the current fall. As the aluminium melts on, on each coil, you will see the current go up Yes, there’s the one [coil] firing – and there’s the other one firing [too] And as the aluminium melts off you see the current return again. The aluminium adds to the conductivity of the tungsten And now its all clean … and we can turn it back. This is a view into the side porthole. The mirrors can be seen on the left. All valves closed. Closed … diff-pump is off …. and we can open up! Now we can release the vacuum on the tank. Slowly open this valve to let the air back in. Also make sure all the bolts are loose. Now for the big reveal! NOT BAD! Looks pretty good! The tank has two porthole windows which we look through. These will of course also aluminise. So these can be replaced – it is removable. You can take out the glass and take off the alumimium.