by Russ » Tue Jul 20, 2010 8:31 pm
That is an interesting one. As you say, it was heated to beyond boiling point, so it would have been a gas under pressure, looking for a way out of the void in the frame.
So why didn't it come back out of the way it came in? Maybe the engineering types here can answer this one, but given that there must be a way into the void at lake bed temperature and pressure, then what happens to that way in at room temperature, which its been at since it came out of the lake, not just at the oven temperature? And what sort of pressure does a given volume of water generate when turned to steam at 200C?
Is it expected behaviour for any low temperature, high pressure opening to seal up at ambient pressure and temperature, and stay sealed at high temperature, and the much higher pressure of steam compared to water? If you can move a whole train or very large ship just with the power of steam, then why didn't the steam find / blast its way out in the oven?
I can remember an experiment back in 'O' level Physics whereby a washer with a small gap through it was heated, but instead of the gap closing, it stayed as a gap because the ring expanded radially, i.e. outward much more than along the circumference, which it would need to do for the hole to close. Has the opposite happened here, and the presumably tiny hole has closed up at temperatures above lake bottom?
I guess that you're not expecting the Ardox to leak out and show the hole, as if it's there now, then the water would have already leaked through it by evaporation even if was too small for capillary action to bleed it.
What it does show is just how thorough and professional the team are being about the restoration of K7; that's one of the many things that the team doing the work can be proud of.
Mind you it tasted OK to me even after all its been through these past 43yrs, genuine Coniston water alright 
