The leak on the actuator arm bellows has been attempted to be sealed using UHV vacuum seal spray. The spray had the opposite to the desired effect and the leak rate increased. When spraying with helium the leak rate had increased to 1e-9 mbar l/s. After lunch a second application of the vacuum seal spray was attempted, however the leak was not sealed. The base leak rate had also increased to the 1e-10 level up from in the morning and yesterday. With the leak increasing in size and risk of a full failure, we are no longer able to move forward with the bakeout. 

The chamber has been vented and we will move forward with plans for replacing the bellow tomorrow. 

Attached plot shows the most current pumpdown.