Thermite, Part 2 (5 comments)
After the shortcomings we saw last time, some changes were made to the thermite delivery apparatus.
- Twice as much thermite.
- Coarser aluminum powder for a slower, longer burn.
- Disks were surrounded on all sides to give the molten iron a wider damage window.
- Thermite was placed directly on the disks; no melting/pouring necessary.
- Thermite delivery mechanism had much taller sides to stop quite so much material from flying out the top.
We ended up using a PVC pipe to hold the thermite powder. Knowing it wouldn't stand up well against the heat, I looked around and found an aluminum pipe. Then I remembered that the whole point of the exercise is to burn aluminum and opted for the PVC.
Mel tripped the ignition while my dad and I photographed. I was on still photography and in a stroke of luck, managed to snap a photo just as the lower thermite store ignited.
There's also video.
20070319-thermite2.wmv, 428x240, 28 seconds, 1.87MB
It worked much better than last time.
In the immediate aftermath, the liquid metal had flowed down past the drives and was heating them from underneath and something in the drives was making a pretty green flame.
After admiring that for a few minutes, we kicked off the bricks that had supported the PVC pipe and knocked the cinder block onto its side. As I'd been hoping, the bottom was still glowing red hot.
After a few more minutes of cooling, the cinder block came apart and the remains of the disks spilled out.
From the looks of things, the heat hardened the platters to the point of brittleness and most of them shattered. A few of them developed a nice iridescent shine as well.
All in all, this round was a success. The platters cracked and broke, and the rare earth magnets that are used to drive the disk heads lost their magnetism. Any of the platters' magnetic coating that didn't burn off is certainly demagnetized beyond the limits of data recovery.
The kerberos disks are satisfactorily trashed, but that might not be the end of things. I'll likely be retiring the campus PH servers in not too long, and they have social security numbers...