Well I replaced 12 2.75″, 1 4.5″ and 1 6.0″ Viton seals with the Teflon gaskets. Even though my finger tips are numb from the star nuts, I must say these gaskets rule. They seat perfectly and they are as smooth as a baby’s bottom. In the process of replacing one of the 2.75″ ports, it was obvious that the Viton seal was mis-seated. Still gave a decent vacuum (10-6), but I’m glad it’s out of there.
So the cage is now unwired from the electrical feed-through. Fundamental laws of topology and conflict with the replacement of the seals on the feedthrough… The main chamber seal still isn’t closed until I get the cage reconnected to the electrical feed through. But since I have to use the hoist to do that, I’ll leave that task until tomorrow night.
Still, all these gaskets in the system created a large area of out-gassing Viton. Replacing this Viton with Teflon can only be a very, very good thing. I also should remember to get some Everclear to clean up the few fingerprints on the cage. Since I’ll have the chamber open and all. . .
Well, the very kind Michael Hettrick has sent my order of Teflon gaskets for the beast and tomorrow I’ll go about replacing all the Viton gaskets. The main seal will still be copper, and there will be the one Viton gasket at the base. I’m hoping that since this gasket is at the base, next to the pump, it won’t have a huge effect on the pressure of the system – we’ll see. Currently I can get the base pressure down to 10-6 Torr. If I can get an order of magnitude decrease in the base pressure, then I should be doing okay.
Moving forward, at least.