Silicone oil?

[vortex-5]

I noticed that silicone oils is recommended when rubber contact is possible. I also noticed that when mixed surfaces such as metal on plastic silicone is recommended due to the plastic safe nature of it.

after trying it on my bike jockey pullies I noticed that it seems a lot slipperier than the same application non detergent 30 and 20 weight oil.

So is there a reason silicone is a poor choice for metal on metal contact or is it just that silicone oil is more expensive vs mineral oils?

 

[kneesahn]

It’s not a good metal to metal lubricant.

 

[Jetronic]

steel on steel it can cause galling, but that's likely not an issue with different metals.

 

[HankHill]

steel on steel it can cause galling, but that's likely not an issue with different metals.

We used pure silicone vacuum grease on all our vacuum furnaces. It lubricated the gaskets on the doors, a nice smooth thin layer would keep keep a little bit higher vacuum in the chamber than without. I've about three tubes laying in my garage in various locations that would take me hours to find. I use it on my weather seals sparingly to keep them in decent shape. It also is non reactive with materials and gases we used in materials research.

High Vacuum Silicone Grease

 

[Jetronic]

I use it to help sealing aswell, but the grease has a very high viscosity (5000 cSt). This could help in preventing galling, but nonetheless I can't think of any place I use it as a lubricant steel on steel.