I cleaned the 10" to 4.5" CF Zero Length Reducer Flange and the two 10" to 2.75" CF Zero Length Reducer Flanges on the Demonstrator IFO Vacuum Cube from duct tape and its residue with wipes, acetone, and a bit of isopropanol. The 10" to 4.5" CF Zero Length Reducer Flange has some grime that I partially removed. I tightened the bolts on the 4.5" CF Flange to 27 Nm which seemed to give a steel to steel contact such that the copper gasket wasn't visible. I tightened the bolts on the 2.75" CF Flanges to 18.6 - 19 Nm which gave a steel to steel contact. Next steps are to install the 10" to 6" Zero Length Reducer Flange, the 6" 6 way cross and all of the vacuum parts off of it.