A recent thread motivated me to do a little research into assembly lubes related to turbo applications. Obviously, turbo systems operate at higher temperatures than NA components, with temps reaching 1600F in high-performance applications, and 1300-1400F being common.
I have always made it a habit to use the proper assembly lubes, anti-seize, thread sealers, thread-locker, etc. In the case of the turbo system, I initially assumed moly based assembly lubes and anti-seizes would be acceptable, but realized that it loses it's effectiveness at around 700F, and the moly actually becomes corrosive at 1000F, well within the normal operating range of a turbo application.

I recently found some copper-based Loctite C-5A anti-seize which is rated up to 1800F. I thought that was a good solution but found out that at elevated temperatures, the copper-based antiseize could actually become corrosive to stainless steel.

Further research indicated that a nickel based anti-seize/lubricant is more appropriate, especially with stainless steel fasteners. The nickel-based formulas offer protection up to 2400F, well beyond the range of applicable turbo applications. Besides being the appropriate anti-seize for a fastener on the hot side of the turbo system, it is also appropriate for the wastegate puck lubrication.

 

dude are you an engineer??

 

No, I'm not an engineer. I jus like to research the details in order to make the most informed decisions possible. I intially used moly assembly lube on the wastegates when I reassembled them. If I had run it like that, over time the moly would have become corrosive to the wastegate shaft due to the high heat. Luckily, I found out about this and I disassembled the wastegate, cleaned the moly off, and used the appropriate nickel anti-seize/lube.

The one I found is made by Loctite, here's the Technical Data Sheet for it. I found it at a local industrial supply warehouse.


Something else I just read that I didn't know:

A stainless steel must contain at least 12% chromium, but lean chromium steels can still show rust on the surface. Using 18% chromium will make a more rust resisting stainless steel.

Exposing any stainless steel to oxygen at temperatures above 1200F will cause the chromium to join oxygen and therefore leave the surface depleted in chromium - if it falls below 12% the surface will show rust.

 

As far as I know there are only 2 antisiezes that are actually good for this application, that's the nickle and ceramic based ones. Unfortunatly I haven't found a good source for either locally.

The silvery stuff that you find at most autoparts stores is acutally aluminum/copper based. I hate the stuff, nothing is a bigger pain in the butt to get off of stuff. Supposedly the ceramic stuff is fairly easy to clean up (never seen it in person).