Originally Posted By: turtlevette
The Bechtel people told me they used STP on the turbine shaft of a 635 MVA coal fired unit I worked on back in the early 80s, when under construction. I guess they had to rotate it ever so many days so it wouldn't permanently have a bend. I thought they were hicks but it sounds like that's a thing. As I remember, they had to take it all apart before startup to clean everything as the STP had almost hardened.
Don't see any chance of the STP hardening, there's no apparent mechanism for it...Lucas is better, as the ZDDP isn't really good for the white metal bearings, (but mixed in with 20,000 gals of turbine oil is pretty not much of an issue).
After you've done the alignments, you need to partially disassemble everything and do systemic oil flushing to get all the footprints, pocket lint and gauge wire out of the system before you run it up.
The brightstock type lubes are only used when jacking oil is unavailable, as often safety rules won't let you have energy sources into the workspace, and the thick stuff is a workaround...besides, if you use jacking oil, it takes an hour or so for the shaft to settle after a move, and if you are aiming for 0.001" alignment, you need to let it settle.
Originally Posted By: turtlevette
I used to use the STP in my engine with thick oil probably 20W-50. When I tore it down it had a layer of goop where the oil does not move much.
I'm anti thick oil these days.
I'm not pro 20W-50, and especially not 20W-50 with STP in it anymore...210 tonnes of turbine (886MVA) is quite happy on 6-10cst oil at 100C...also quite happy running a straight weight.